Arquivo da tag: Formigas

¿Adiós al Servicio Meteorológico? Un biólogo argentino predice el clima estudiando hormigas (y acierta) (La Nación)

Jorge Finardi anticipa lluvias y tormentas a partir del comportamiento de insectos

LA NACION

JUEVES 26 DE ENERO DE 2017 • 17:44

¿Chau Servicio Meteorológico? El biólogo argentino que predice el clima estudiando hormigas

¿Chau Servicio Meteorológico? El biólogo argentino que predice el clima estudiando hormigas. Foto: Archivo 

Jorge Finardi predice el clima a través de las hormigas. Estudia sus movimientos, los registra, los compara y llega a la conclusión, por ejemplo, de que mañana a la tarde lloverá. Y acierta. Esta semana, Finardi anticipó con su método el calor sofocante del lunes, la tormenta del martes, y la caída de la temperatura del miércoles. Nada mal.

Finardi es químico, biólogo, y lleva adelante la cuenta de Twitter @GeorgeClimaPron. En ella, comunica sus pronósticos climatológicos. En una entrevista con LA NACION, explica su sistema.

-¿Cómo funciona tu método de análisis?

-En primer lugar, determino el grado de actividad de las hormigas en una escala del 1 al 10. Para armar la escala tengo en cuenta la cantidad de interacciones entre las hormigas, el número de hormigas involucradas, y el tipo y tamaño de carga que llevan, además, de la clase de hormiga que trabaja.

-¿Y de qué manera se relaciona con el clima? ¿Más actividad es indicativa de lluvia?

-En parte sí, pero depende de la carga que lleven. Por ejemplo, cuando las hormigas llevan palitos y barritas, es porque tienen que fortalecer el hormiguero, debido a que se aproxima lluvia o frío. Cuando hay movilización de tierra es porque se viene una lluvia fuerte. Cuando llevan cereal, viene frío, porque el cereal fermenta dentro del hormiguero y produce calor para que nazcan los hongos que ellas comen.

Para las altas temperaturas, por otro lado, se acondicionan los túneles: las hormigas empiezan a abrir “chimeneas”, que son como agujeritos esparcidos dentro del hormiguero, que puede llegar a tener metros de profundidad. Cuando pasa eso, se viene una ola de calor.

-¿Cómo te interesaste por el tema?

-Desde los tres años me paso horas mirando las hormigas y todo tipo de insectos. Por otro lado, mi profesión me ayudó a profundizar estos temas, y también a hablar con gente de edad avanzada que vive en el campo y no se fija en los pronósticos. No los necesita. Así avancé. Así y con un poco de prueba y error. Al principio introduje hormigas en un terrario para poder observarlas más cómodo. Pero ellas se comportaban de otra manera, por el aislamiento. Ahora las sigo con una cámara.

-¿Además de las hormigas, analizás otros insectos?

-Sí. Las arañas, por ejemplo, tienen la capacidad de detectar actividad eléctrica, cuando aparecen y están muy activas. Las libélulas pueden anticipar una tormenta o viento. Las cigarras anuncian calor. Los gallos, cuando cantan a media noche, anuncian neblinas. También hay que prestar atención a las hormigas cuando están desorientadas, porque pueden captar actividad sísmica a grandes distancias.

-¿Este tipo de análisis es científico?

-No. Hay que destacar que el método no es científico, no es positivista, pero sí es cualitativo, experimental y observacional. Y sirve. Los hombres estamos acá desde el período cuaternario, pero las hormigas, por ejemplo, están desde la época de los dinosaurios. Están muy adaptadas, son muy sensibles a los cambios de ambiente. Y la naturaleza, así, nos habla, nos presenta síntomas. Hay que saber leerlos.

Anúncios

The Ant, the Shaman and the Scientist: Shamanic lore spurs scientific discovery in the Amazon (Notes from the Ethnoground)

NOVEMBER 22, 2011

When he pointed to the tree trunk and said the scars were from fires set by invisible forest spirits, I had no idea this supernatural observation would lead to a new discovery for natural science.  Mariano, the eldest shaman of the Matsigenka village of Yomybato in Manu National Park, Peru, had first showed me the curious clearings in the forest that form around clumps of Cordia nodosa, a bristly tropical shrub related to borage (Borago officinalis).  Both the Matsigenka people and tropical ecologists recognize the special relationship that exists between Cordia and ants of the genus Myrmelachista: the Matsigenka word for the plant is matiagiroki, which means “ant shrub.”

 SupaiChacra2
Maximo Vicente, Mariano’s grandson, standing by a 
swollen, scarred trunk near a Cordia patch.

For scientists, the clearings in the forest understory around patches of Cordia are caused by a mutualistic relationship with the ants.  Cordia plants provide the ant colony with hollow branch nodes for nesting and bristly corridors along twigs and leaves for protection, while the ants use their strong mandibles and acidic secretions to clear away competing vegetation.  Local Quechua-speaking colonists refer to the clearings as “Devil’s gardens” (supay chacra).  For the Matsigenka, these clearings are the work of spirits known as Sangariite, which means ‘Pure’ or ‘Invisible Ones’.  Matsigenka shamans like Mariano come to these spirit clearings and consume powerful narcotics and hallucinogens such as tobacco paste, ayahuasca (Banisteriopsis), or the Datura-like toé (Brugmansia).[1]

 SupaiChacra
A “Sangariite village clearing” (igarapagite sangatsiri)
in the upland forests of Manu Park.

With the aid of visionary plants, the shaman perceives the true nature of these mundane forest clearings: they are the villages of Sangariite spirits, unimaginably distant and inaccessible under ordinary states of consciousness.  While in trance, the shaman enters the village and develops an ongoing relationship with a spirit twin or ally among the Sangariite, who can provide him or her with esoteric knowledge, news from distant places, healing power, artistic inspiration, auspicious hunting and even novel varieties of food crops or medicinal plants.[2]  As proof of the existence of these invisible villages, Mariano pointed out to me the scars on adjacent tree trunks all around large, dense Cordia patches: “The scars are caused by fires the Sangariite set to clear their gardens every summer,” he explained.

 jaguarshaman
Mariano wearing a cotton tunic with designs taught him by the
Sangariite spirits during an ayahuasca trance.

Douglas Yu, an expert on ant-plant interactions, was researching Cordia populations in the forests around Yomybato.[3]  I told him of Mariano’s observations about the Sangariite villages, and pointed out the distinctive marks on adjacent trees.  In his years of research, Yu had never noticed the trunk scars.  Intrigued, he cut into the scars and found nests teeming with Myrmelachista ants that appeared to be galling the trunks to create additional housing.  As detailed in a 2009 publication in American Naturalist[4], this case is the first recorded example of ants galling plants, reopening a century-old debate in tropical ecology begun by legendary scientists Richard Spruce and Alfred Wallace. The discovery of Myrmelachista‘s galling capability also helped Yu understand how this ant species persists in the face of competition by two more aggressive ant types, Azteca and Allomerus, that can also inhabit Cordia depending on ecological conditions.

 DougYuAnts
Douglas Yu carries out research on ant-plant
interactions in the Peruvian Amazon.

My ongoing collaborations with Yu and other tropical biologists in indigenous communities have highlighted how important it is to pay attention to local people’s rich and often underappreciated knowledge about forest ecosystems: sometimes even those elements of folklore that appear quaint or “unscientific” contain astute insights about natural processes.

 AntGall
Cross section of a tree trunk galled by Myrmelachista ants
(photo: Megan Frederickson).

— This article was first published online on Nov. 7, 2011 with Spanish and Portuguese translations by O Eco Amazônia.

References:

[1] G.H. Shepard Jr. (1998) Psychoactive plants and ethnopsychiatric medicines of the Matsigenka. Journal of Psychoactive Drugs 30 (4):321-332; G.H. Shepard Jr. (2005) Psychoactive botanicals in ritual, religion and shamanism. Chapter 18 in: E. Elisabetsky & N. Etkin (Eds.), Ethnopharmacology. Encyclopedia of Life Support Systems (EOLSS), Theme 6.79. Oxford, UK: UNESCO/Eolss Publishers [http://www.eolss.net].

[2] G.H. Shepard Jr. (1999) Shamanism and diversity:  A Matsigenka perspective. In Cultural and Spiritual Values of Biodiversity, edited by D. A. Posey. London: United Nations Environmental Programme and Intermediate Technology Publications.

[3] D.W. Yu, H. B. Wilson and N. E. Pierce (2001) An empirical model of species coexistence in a spatially structured environment. Ecology 82 (6):1761-1771.
[4] D.P. Edwards, M.E. Frederickson, G.H. Shepard Jr. and D.W. Yu (2009) ‘A plant needs its ants like a dog needs its fleas’: Myrmelachista schumanni ants gall many tree species to create housing. The American Naturalist 174 (5):734-740. [http://www.ncbi.nlm.nih.gov/pubmed/19799500]

Posted by Glenn H. Shepard at 10:11 AM

Alternate mechanism of species formation picks up support, thanks to a South American ant (University of Rochester )

21-Aug-2014

 

By Peter Iglinski

A queen ant of the host species Mycocepurus goeldii.

A newly-discovered species of ant supports a controversial theory of species formation. The ant, only found in a single patch of eucalyptus trees on the São Paulo State University campus in Brazil, branched off from its original species while living in the same colony, something thought rare in current models of evolutionary development.

“Most new species come about in geographic isolation,” said Christian Rabeling, assistant professor of biology at the University of Rochester. “We now have evidence that speciation can take place within a single colony.”

The findings by Rabeling and the research team were published today in the journal Current Biology.

In discovering the parasitic Mycocepurus castrator, Rabeling and his colleagues uncovered an example of a still-controversial theory known as sympatric speciation, which occurs when a new species develops while sharing the same geographic area with its parent species, yet reproducing on its own.“While sympatric speciation is more difficult to prove,” said Rabeling, “we believe we are in the process of actually documenting a particular kind of evolution-in-progress.”

New species are formed when its members are no longer able to reproduce with members of the parent species. The commonly-accepted mechanism is called allopatric speciation, in which geographic barriers—such as mountains—separate members of a group, causing them to evolve independently.

“Since Darwin’s Origin of Species, evolutionary biologists have long debated whether two species can evolve from a common ancestor without being geographically isolated from each other,” said Ted Schultz, curator of ants at the Smithsonian’s National Museum of Natural History and co-author of the study. “With this study, we offer a compelling case for sympatric evolution that will open new conversations in the debate about speciation in these ants, social insects and evolutionary biology more generally.”

A queen ant of the parasitic species Mycocepurus castrator.

M. castrator is not simply another ant in the colony; it’s a parasite that lives with—and off of—its host, Mycocepurus goeldii. The host is a fungus-growing ant that cultivates fungus for its nutritional value, both for itself and, indirectly, for its parasite, which does not participate in the work of growing the fungus garden. That led the researchers to study the genetic relationships of all fungus-growing ants in South America, including all five known and six newly discovered species of the genus Mycocepurus, to determine whether the parasite did evolve from its presumed host. They found that the parasitic ants were, indeed, genetically very close to M. goeldii, but not to the other ant species.

They also determined that the parasitic ants were no longer reproductively compatible with the host ants—making them a unique species—and had stopped reproducing with their host a mere 37,000 years ago—a very short period on the evolutionary scale.

A big clue for the research team was found by comparing the ants’ genes, both in the cell’s nucleus as well as in the mitochondria—the energy-producing structures in the cells. Genes are made of units called nucleotides, and Rabeling found that the sequencing of those nucleotides in the mitochondria is beginning to look different from what is found in the host ants, but that the genes in the nucleus still have traces of the relationship between host and parasite, leading him to conclude that M. castrator has begun to evolve away from its host.

Rabeling explained that just comparing some nuclear and mitochondrial genes may not be enough to demonstrate that the parasitic ants are a completely new species. “We are now sequencing the entire mitochondrial and nuclear genomes of these parasitic ants and their host in an effort to confirm speciation and the underlying genetic mechanism.”

The parasitic ants need to exercise discretion because taking advantage of the host species is considered taboo in ant society. Offending ants have been known to be killed by worker mobs. As a result, the parasitic queen of the new species has evolved into a smaller size, making them difficult to distinguish from a host worker.

Host queens and males reproduce in an aerial ceremony, in the wet tropics only during a particular season when it begins to rain. Rabeling found that the parasitic queens and males, needing to be more discreet about their reproductive activities, diverge from the host’s mating pattern. By needing to hide their parasitic identity, M. castrator males and females lost their special adaptations that allowed them to reproduce in flight, and mate inside the host nest, making it impossible for them to sexually interact with their host species.

The research team included Ted Schultz of the Smithsonian Institution’s National Museum of Natural History, Naomi Pierce of Harvard University, and Maurício Bacci, Jr of the Center for the Study of Social Insects (São State University, Rio Claro, Brazil).

Cientistas exploram microbiota de formigas em busca de novos fármacos (Fapesp)

Projeto reúne pesquisadores da USP e de Harvard e foi aprovado na primeira chamada conjunta lançada pela FAPESP e pelo NIH (foto: Michael Poulsen/capa: Eduardo Afonso da Silva Jr.)

11/07/2014

Por Karina Toledo

Agência FAPESP – Como os moradores de grandes cidades bem sabem, ambientes com grande aglomeração de indivíduos são favoráveis à disseminação de patógenos e, portanto, requerem cuidados para evitar doenças.

Se nós humanos podemos contar com vacinas, remédios e desinfetantes para nos proteger, os insetos sociais – como abelhas, formigas e cupins – também desenvolveram ao longo de milhares de anos de evolução suas próprias “armas químicas”, que agora começam a ser exploradas pela ciência.

“Uma das estratégias usadas por insetos que vivem em colônias é a associação com microrganismos simbiontes – na maioria das vezes bactérias – capazes de produzir compostos químicos com ação antibiótica e antifúngica”, contou Monica Tallarico Pupo, professora da Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP) da Universidade de São Paulo (USP).

Em um projeto recentemente aprovado na primeira chamada de propostas conjunta lançada pela FAPESP e pelo National Institutes of Health (NIH), dos Estados Unidos, a equipe de Pupo vai se unir ao grupo de Jon Clardy, da Harvard University, para explorar a microbiota existente nos corpos de formigas brasileiras em busca de moléculas naturais que possam dar origem a novos fármacos.

“Vamos nos concentrar inicialmente nas espécies de formigas cortadeiras, como a saúva, pois são as que têm essa relação de simbiose mais bem descrita na literatura científica”, disse Pupo.

De acordo com a pesquisadora, as formigas cortadeiras se comportam como verdadeiras agricultoras, carregando pedaços de planta para o interior do ninho com o intuito de nutrir as culturas de fungos das quais se alimentam. “Isso cria um ambiente rico em nutrientes e suscetível ao ataque de microrganismos oportunistas. Para manter a saúde do formigueiro, é importante que tenham os simbiontes associados”, explicou Pupo.

Os pesquisadores sairão à caça de formigas em parques nacionais localizados em diferentes biomas brasileiros, como Cerrado, Mata Atlântica, Amazônia e Caatinga. Também fará parte da área de coleta o Parque Estadual Vassununga, no município de Santa Rita do Passa Quatro (SP).

A meta do grupo é isolar cerca de 500 linhagens de bactérias por ano o que, estima-se, dê origem a cerca de 1.500 diferentes extratos. “O primeiro passo será coletar os insetos e fragmentos do ninho para análise em laboratório. Em seguida, vamos isolar as linhagens de bactérias existentes e usar métodos de morfologia e de sequenciamento de DNA para caracterizar os microrganismos”, contou Pupo.

Depois que as bactérias estiverem bem preservadas e catalogadas, acrescentou a pesquisadora, será possível cultivar as linhagens para, então, extrair o caldo de cultivo. “Nossa estimativa é que cada linhagem dê origem a três diferentes extratos, de acordo com o nutriente usado no cultivo e a técnica de extração escolhida”, disse.

Esses extratos serão testados in vitro para avaliar se são capazes de inibir o crescimento de fungos, células cancerígenas e de parasitas causadores de leishmanioses e doença de Chagas. Os mais promissores terão os princípios ativos isolados e estudados mais profundamente.

“Nesse tipo de pesquisa é comum ter redundância, ou seja, isolar compostos já conhecidos na literatura. Para agilizar a descoberta de novas substâncias ativas vamos usar ferramentas de desreplicação e de sequenciamento genômico”, disse Pupo.

Também farão parte da equipe o bacteriologista Cameron Currie (University of Wisconsin-Madison), Fabio Santos do Nascimento (Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto da USP), André Rodrigues (Universidade Estadual Paulista em Rio Claro), Adriano Defini Andricopulo (Instituto de Física de São Carlos, da USP), James E. Bradner (Harvard Medical School), Dana-Farber (Cancer Institute), Timothy Bugni (University of Wisconsin – Madison) e David Andes (University of Wisconsin – Madison).

A chamada Fapesp/NIH está vinculada ao programa International Biodiversity Cooperative Groups (ICBG), do qual o Brasil participa pela primeira vez.

Início

Segundo Pupo, o projeto colaborativo é uma ampliação do trabalho que vem sendo realizado no âmbito de um Auxílio Regular aprovado em meados de 2013, que também conta com a colaboração de Clardy e de Currie.

“Estamos estudando uma espécie de abelha [ Scaptotrigona depilis] e uma espécie de formiga [Atta sexdens] encontradas no campus da USP em Ribeirão Preto. Nesse caso, exploramos toda a microbiota dos insetos, tanto bactérias quanto fungos, e alguns compostos isolados estão apresentando potencial antibacteriano e antifúngico bastante acentuado”, contou.

O trabalho está sendo desenvolvido durante o doutorado de Eduardo Afonso da Silva Júnior eCamila Raquel Paludo – ambos com Bolsa da FAPESP. Também tem a participação da bolsista de Iniciação Científica Taise Tomie Hebihara Fukuda.

Formigas são mais eficientes em busca do que o Google, diz pesquisa (O Globo)

JC e-mail 4960, de 27 de maio de 2014

O estudo mostrou que insetos desenvolvem complexos sistemas de informação para encontrar alimentos

Todos aprendemos desde pequenos que as formigas são prudentes, e que enquanto a cigarra canta e toca violão no verão, esses pequenos insetos trabalham para coletar alimento suficiente para todo o inverno. No entanto, segundo estudo publicado na revista Procedimentos da Academina Nacional de Ciências, elas não só são precavidas, mas também “muito mais eficientes que o próprio Google”.

Para chegar a essa inusitada conclusão, cientistas chineses e alemães utilizaram algorítimos matemáticos que tentam enxergar ordem em um aparente cenário caótico ao criar complexas redes de informação. Em fórmulas e equações, descobriu-se que as formigas desenvolvem caminhos engenhosos para procurar alimentos, dividindo-se em grupos de “exploradoras” e “agregadoras”.

Aquela formiga encontrada solitária que você encontra andando pela casa em um movimento aparentemente aleatório é, na verdade, a exploradora, que libera feromônios pelo caminho para que as agregadoras sigam o trajeto posteriormente com um maior contigente. Com base no primeiro trajeto, novas rotas mais curtas e eficientes são refinadas. Se o esforço for repetido persistentemente, a distância entre os insetos e a comida é drasticamente reduzida.

– Enquanto formigas solitárias parecem andar em movimento caótico, elas rapidamente se tornam uma linha de formigas cruzando o chão em busca de alimento – explicou ao The Independent o co-autor do estudo, professor Jurgen Kurths.

Por isso, segundo Kurths, o processo de busca de um alimento realizado pelos insetos é “muito mais eficiente” do que a ferramenta de pesquisa do Google.

Os modelos matemáticos do estudo podem ser igualmente aplicados a outros movimentos coletivos de animais, inclusive em humanos. A ferramenta pode ser útil, por exemplo, para entender o comportamento das pessoas em redes sociais e até em ambientes de transporte público lotado.

(O Globo com Agências)
http://oglobo.globo.com/sociedade/ciencia/formigas-sao-mais-eficientes-em-busca-do-que-google-diz-pesquisa-12614920#ixzz32vCQx2oB

Ciência busca fármacos em formigas (O Estado de São Paulo)

JC e-mail 4958, de 23 de maio de 2014

Pesquisa apoiada pelo NIH e Fapesp vai estudar bactérias que vivem na carapaça dos insetos e têm capacidade de destruir fungos

A busca por moléculas naturais capazes de combater doenças em seres humanos sempre foi um trabalho “de formiguinha” da ciência, envolvendo a coleta, isolamento e análise de milhares de compostos de plantas, animais e micróbios da natureza, que precisam ser testados, um a um, sobre uma grande variedade de alvos terapêuticos. No caso de um novo projeto de pesquisa anunciado ontem, porém, essa expressão ganha sentido literal.

Cientistas do Brasil e dos Estados Unidos vão, literalmente, enfiar a mão em formigueiros e coletar formigas por todo o País em busca de novas moléculas capazes de destruir fungos, parasitas e, quem sabe, até células cancerígenas. Não nos insetos propriamente ditos, mas nas bactérias que vivem sobre suas carapaças e impedem que suas colônias subterrâneas sejam contaminadas por fungos nocivos à sua sobrevivência.

O projeto foi aprovado “com louvor” num edital conjunto dos Institutos Nacionais de Saúde dos Estados Unidos (NIH) e da Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp), cujo resultado foi anunciado ontem pelo presidente do NIH, Francis Collins, em sua primeira visita ao Brasil. O projeto está previsto para durar cinco anos, e o valor de financiamento ainda não foi divulgado oficialmente pelas instituições.

Mônica TallaricoPupo, da Faculdade de Ciências Farmacêuticas da Universidade de São Paulo (USP) em Ribeirão Preto, é a pesquisadora principal do lado brasileiro. Jon Clardy, de Harvard, lidera pelo lado americano.

A meta, segundo Mônica, é isolar cerca de 500 linhagens de bactérias simbiontes de formigas por ano, para serem testadas contra fungos infecciosos (que atacam, principalmente, pacientes com sistema imunológico comprometido), parasitas tropicais (em especial, os da doença de Chagas e leishmaniose) e células tumorais.

“Vamos começar pelas formigas agricultoras”, diz ela, que já desenvolve um projeto semelhante, de menor escala, com formigas saúvas. Agora, serão coletadas amostras de várias espécies, de biomas brasileiros: Amazônia, Cerrado, Mata Atlântica e Caatinga.

Fazendeiras. O termo “agricultoras” refere-se ao fato de essas formigas cultivarem “plantações” de fungos dentro de seus formigueiros. Os pedaços de folhas que elas carregam para dentro das colônias não é alimento para elas, mas para os fungos – que, por sua vez, são o verdadeiro alimento das formigas.

Como todo bom agricultor, as formigas não querem que suas plantações sejam contaminadas por pragas – neste caso, fungos oportunistas, que não servem de alimento para elas. E quem evita que elas carreguem esporos desses fungos para dentro dos formigueiros são bactérias que vivem em suas carapaças e destroem rapidamente esses organismos.

A meta dos cientistas é estudar essas bactérias e descobrir as moléculas que elas usam para destruir os fungos. Feito isso, a esperança é que algumas dessas moléculas sirvam como base para o desenvolvimento de novos fármacos.

A vantagem com relação a projetos semelhantes, que buscam moléculas com ação farmacológica na biodiversidade, é que a “triagem inicial de bactérias já foi feita pelas formigas”, aponta Mônica.

Collins falou com entusiasmo do projeto nesta quinta-feira, 22, na Fapesp. “Não é uma ideia incrível?”, disse. “Uma série de compostos completamente novos poderá emergir dessa pesquisa.” O projeto recebeu a melhor nota entre todos que foram submetidos ao NIH no edital.

(O Estado de São Paulo)
http://www.estadao.com.br/noticias/vida,ciencia-busca-farmacos-em-formigas,1170284,0.htm

Could Ants Teach the Biofuel Industry a Thing or Two? (Quest)

Post by  , Producer for on Sep 26, 2013

Leafcutter ants, native to Central and South America, can't digest the leaves they rely on for food, so they cultivate these gardens of fungi and bacteria to break down plant matter for them.

Leafcutter ants, native to Central and South America, can’t digest the leaves they rely on for food, so they cultivate these gardens of fungi and bacteria to break down plant matter for them. Photo courtesy of Alex Wild; used with permission.

In the lobby of the Microbial Sciences building at the University of Wisconsin, leafcutter ants in adisplay colony hike back and forth. Improbably large leaf fragments wobble on their backs as the ants ferry them between a dwindling pile of oak leaves and a garden of fungus studded with leaves in assorted states of decay.

Made up of a single species of fungus and a handful of bacterial strains, the fungus garden breaks down the ants’ leafy harvest through an efficient natural process. It’s a process that researchers believe could be a model for producing biofuel in a more sustainable way.

As we transition away from petroleum dependence, ethanol-based biofuel has risen to the forefront as one of the most accessible sources of renewable energy. It’s produced by fermenting plant sugars, which are strung together into long chains called polysaccharides. Before the fermentation process can begin, these chains have to be snipped apart, a process that varies in difficulty depending on the type of plant being used.

Polysaccharide chains found in corn kernels — the primary biofuel crop in the U.S. — are relatively simple to break up. But corn depletes the soil and guzzles water and fertilizer, and using it for fuel siphons calories from the food supply to gas tanks.

On the other hand, perennial grasses and agricultural “waste” like cornstalks offer a biofuel source that has a lighter impact on the environment. But these woodier fibers — referred to as“cellulosic” biomass — are a tangle of robust polysaccharides that are trickier to deconstruct. Further complicating this problem, the molecular structure of plant biomass isn’t uniform. What breaks down the polysaccharides near the surface of a cornstalk or blade of grass might not work at all on those buried more deeply.

DSC_0025

University of Wisconsin researcher Frank Aylward peers into one of the lab’s many leafcutter ant colonies.

But finding efficient ways to extract energy from plants and other forms of biomass is not a new problem. In fact, it’s a problem that Earth’s plant eaters solved millions of years ago. And according to University of Wisconsin researcher Frank Aylward, if you’re looking for a model system, you can’t do better than leafcutter ants.

They may not have the imposing mien of herbivores like giraffes or elephants, but in Central and South America, leafcutter ants dominate, munching through more of the region’s foliage than any other organism.

But the ants can’t digest leaves by themselves — they have to rely on the garden’s microbes. “We sort of think of the fungus gardens as being an external gut,” Aylward explains. The garden digests biomass and reconstitutes its molecules in little nutrient packets holding a cocktail of carbohydrates, lipids, and proteins.

“The ants are essentially doing what we want to do with biofuel,” says Aylward. “They’re taking all of this recalcitrant plant biomass that’s full of all of these really complicated polymers and they’re degrading it and converting it into energy.” The transformation from leafy greens to energy source is mediated by hundreds of enzymes produced by the fungus garden’s microbes. If these enzymes chow down so efficiently on the leaves of Central America, Aylward and his coworkers wondered, could they be just as effective at breaking apart the sugars of cellulosic biomass in an industrial setting?

One model for a commercial biofuel process patterned after the fungus garden could entail splicing the genetic codes for the garden’s most effective enzymes into other microbes, prompting them to churn out biomass-digesting proteins.

But first, scientists needed to identify which enzymes the garden uses to digest leaves for the ants and which microbial residents produce them. By sequencing the genomes of the fungus and bacteria and comparing that data to the garden’s enzyme soup, Aylward and his coworkers were able to identify a fungus called Leucoagaricus gongylophorus as the garden’s biomass-degrading workhorse.

Aylward extracts a fragment of the fungus garden. This segment was near the surface, and still shows visible leaf matter; the biomass  in the garden sinks as it's broken down.

Aylward extracts a fragment of the fungus garden. This segment was near the surface, and still shows visible leaf matter; the biomass in the garden sinks as it’s broken down.

They also found that the fungus calibrates its enzyme cocktail for different stages of leaf decay. The biomass profile changes at each level in the garden — the freshest leaves sit near the top and the mostly decomposed waste material at the bottom. And Aylward found that the garden’s enzymes changed, too. That insight could provide the biofuel industry with some clues about which enzymes might excel early in the polysaccharide-decomposition process and which ones to apply later on.

Incidentally, this division of labor also reveals which enzymes the garden deploys together at each level. This is a huge boon to anyone designing industrial applications, since enzymes tend to work much better in specific combinations — and the garden has had 50 million years of symbiosis with the ants to find the most efficient combinations.

Aylward has already been approached by companies interested in synthesizing some of the garden’s enzymes and using them in biofuel production.

“It’s difficult to think that we can actually find a process that improves on nature,” Aylward points out, “so it probably makes sense to learn from it.”

Ants and Carnivorous Plants Conspire for Mutualistic Feeding (Science Daily)

May 22, 2013 — An insect-eating pitcher plant teams up with ants to prevent mosquito larvae from stealing its nutrients, according to research published May 22 in the open access journal PLOS ONE by Mathias Scharmann and colleagues from the University of Cambridge and the University Brunei Darussalam.

The carnivorous pitcher plant Nepenthes bicalcarata (A) and the ant Camponotus schmitzi (B) team up to fight fly larvae (C) that steal the plant’s prey. (Credit: Scharmann M, Thornham DG, Grafe TU, Federle W (2013) A Novel Type of Nutritional Ant–Plant Interaction: Ant Partners of Carnivorous Pitcher Plants Prevent Nutrient Export by Dipteran Pitcher Infauna. PLoS ONE 8(5): e63556. doi:10.1371/journal.pone.0063556)

The unusual relationship between insect-eating pitcher plants and ants that live exclusively on them has long puzzled scientists. The Camponotus schmitzi ants live only on one species of Bornean pitcher plants (Nepenthes bicalcarata), where they walk across slippery pitcher traps, swim and dive in the plant’s digestive fluids and consume nectar and prey that fall into the trap. Though the benefits to the ants are obvious, it has been harder to tell what exactly the plants gain. However, plants that harbor the insects grow larger than those that do not, suggesting a mutualistic relationship exists between the two.

In this new study, researchers demonstrated a flow of nutrients from ants to their plant hosts, and found that plants colonized by insects received more nitrogen than those that did not host ants. Ants appeared to increase the pitchers’ capture efficiency by keeping traps clean, and also protected the plants by actively hunting mosquito larvae that otherwise bred in pitcher fluids and sucked up plant nutrients.

“Kneeling down in the swamp amidst huge pitcher plants in a Bornean rainforest, it was a truly jaw-dropping experience when we first noticed how very aggressive and skilled theCamponotus schmitzi ants were in underwater hunting: it was a mosquito massacre!” says Scharmann. “Later, when we discovered that the ants’ droppings are returned to the plant, it became clear that this unique behaviour could actually play an important role in the complex relationship of the pitcher plant with the ants.”

Based on these observations, the authors suggest that nutrients the pitchers would have otherwise lost to flies are instead returned to them as ant colony wastes. They conclude that the interaction between ants, pitcher plants and mosquito larvae in the pitcher represents a new type of mutualism, where animals can help mitigate the damage caused by nutrient thieves to a plant.

Journal Reference:

  1. Mathias Scharmann, Daniel G. Thornham, T. Ulmar Grafe, Walter Federle. A Novel Type of Nutritional Ant–Plant Interaction: Ant Partners of Carnivorous Pitcher Plants Prevent Nutrient Export by Dipteran Pitcher Infauna.PLoS ONE, 2013; 8 (5): e63556 DOI:10.1371/journal.pone.0063556

The Ant-Driven Landscape (Quest)

http://science.kqed.org

Post on Mar 14, 2013 by  from 

In this part of California we may thank our lucky stars for being free of Burmese pythonsbrown recluse spidersor Africanized honeybees. But during the last few decades, while most of us weren’t paying attention, much of California was taken over by ants from Argentina.

Argentine ants, Linepithema humile, love the environment of our homes and gardens. The soil is watered regularly, there’s warmth nearby in the winter, and it almost never floods. The species is aggressive, and unlike most ants they don’t fight each other’s colonies. Recent research suggests that even though they’re genetically diverse, Argentine ants always smell the same to each other, so undistracted by internal wars they combine forces and simply overwhelm most other ant species.

But our different kinds of native ants are crucial members of the local ecosystem. Some eat corpses, while others scavenge the ground for dead plant matter. Some live like farmers, cultivating certain fungus species by feeding them plant materials. Some depend on specific plants, which benefit from the attention. (KQED has acool gallery of Bay Area native ant species and their lifeways.)

When the Argentine ants move in, all of those specialized services are handicapped or disappear. There’s plenty of reading out there about the effect of these ants on ecosystems, but as a geologist I wonder about their effect on bioturbation, the processes by which living things stir the soil. Ground-dwelling animals have profound effects on soil: the way it breathes, circulates water and cycles nutrients. Ants and worms are the most important of these.

Among the various ant species, Argentine ants are small and their nests are shallow. That means, for instance, they’re not capable of building the piles of coarse sand and gravel, brought up from meters below the ground, that desert red ants made in this example from Nevada.

Photos by Andrew Alden

Photos by Andrew Alden

Fortunately Argentine ants have trouble where it’s dry and cold, so gold prospectors in the Mojave can continue their practice of sampling buried rocks from anthills. But around here, how does the soil respond when the deep-digging ant species are gone? I also wonder about the various bee species that dig holes in the ground, like these ones I spotted on a San Mateo County seacliff.

bees

As scientists learn more about invasive species, it’s clear that no matter wherever they live, people need to raise their game and learn defensive practices: call it eco-hygeine.

Consider the earthworms of Minnesota. Did you know that in Minnesota and much of its neighboring states there aren’t any native earthworms? Since the ice age glaciers melted, some 10,000 years ago, the earthworms haven’t managed to crawl north fast enough, and the forests there are adapted to worm-free soils that consist of raw glacier sediment with a thick layer of organic matter on top. Worms eat all that stuff and dig it into the dirt. That’s why we love them in most places, but in Minnesota the worms brought in with nursery plants and baitworms thrown away during fishing trips are ruining the woods. Up there, the Great Lakes Worm Watch is trying to raise consciousness and fight the problem.

Around here, we have to think more about our ants. At Stanford University’s Jasper Ridge Biological Preserve they’ve been monitoring the Argentine ant invasion and are learning what limits them: cold, dry ground and ant species with strong defenses. Volunteers all over the Bay Area can act locally by gathering data through theBay Area Ant Survey, coordinated by the California Academy of Sciences.

There has been a lot of talk lately about “Anthropocene time,” a name for the geological time period that includes the present and future. It represents a concept I might call the human-driven planet: our actions and influences have become as important as natural forces in governing the planetary environment. The root “anthropo-” refers to human causes, but for teaching purposes it may be better just to look down at our feet and think “ant-” instead. Because humans brought the invaders here.

By the way, Argentine ants are well controlled with boric acid bait. I’ve had lasting success with this simple method.

Epigenetics Shapes Fate of Brain Vs. Brawn Castes in Carpenter Ants (Science Daily)

Feb. 13, 2013 — The recently published genome sequences of seven well-studied ant species are opening up new vistas for biology and medicine. A detailed look at molecular mechanisms that underlie the complex behavioral differences in two worker castes in the Florida carpenter ant, Camponotus floridanus, has revealed a link to epigenetics. This is the study of how the expression or suppression of particular genes by chemical modifications affects an organism’s physical characteristics, development, and behavior. Epigenetic processes not only play a significant role in many diseases, but are also involved in longevity and aging.

Florida carpenter ants – minor (left) and major (right). (Credit: Courtesy Brittany Enzmann, Arizona State University)

Interdisciplinary research led by Shelley Berger, PhD, from the Perelman School of Medicine at the University of Pennsylvania, in collaboration with teams led by Danny Reinberg from New York University and Juergen Liebig from Arizona State University, describe their work in Genome Research. The group found that epigenetic regulation is key to distinguishing one caste, the “majors,” as brawny Amazons of the carpenter ant colony, compared to the “minors,” their smaller, brainier sisters. These two castes have the same genes, but strikingly distinct behaviors and shape.

Ants, as well as termites and some bees and wasps, are eusocial species that organize themselves into rigid caste-based societies, or colonies, in which only one queen and a small contingent of male ants are usually fertile and reproduce. The rest of a colony is composed of functionally sterile females that are divided into worker castes that perform specialized roles such as foragers, soldiers, and caretakers. InCamponotus floridanus, there are two worker castes that are physically and behaviorally different, yet genetically very similar.

Lead author Daniel F. Simola, PhD, a postdoctoral researcher in the Penn Department of Cell and Developmental Biology, explains that “the major is also called a soldier, and it has a much larger head, so the force of its mandibles can break larger prey. It does more nest and colony defense.”

The minor caste, on the other hand, is smaller and more numerous. “They do most of the nursing within a colony, take care of the young, and they will also go out and collect most of the food,” says Simola. “On average, 75 to 80 percent of the foraging activity is done by the minors.” The minor also has a considerably shorter lifespan than the major caste, making the ant castes a good model for longevity studies as well as behavioral studies.

But how do such marked differences arise when both the major and the minor castes share the same genome? “For all intents and purposes, those two castes are identical when it comes to their gene sequences,” notes senior author Berger, professor of Cell and Developmental Biology. “The two castes are a perfect situation to understand how epigenetics, how regulation ‘above’ genes, plays a role in establishing these dramatic differences in a whole organism.”

To understand how caste differences arise, the team examined the role of modifications of histones (protein complexes around which DNA strands are wrapped in a cell’s nucleus) throughout the Camponotus floridanus genome, producing the first genome-wide epigenetic maps of genome structure in a social insect. Histones can be altered by the addition of small chemical groups, which affect the expression of genes. Therefore, specific histone modifications can create dramatic differences between genetically similar individuals, such as the physical and behavioral differences between ant castes.

“These chemical modifications of histones alter how compact the genome is in a certain region,” Simola explains. “Certain modifications allow DNA to open up more, and some of them to close DNA more. This, in turn, affects how genes get expressed, or turned on, to make proteins. These modifications establish specific features of different tissues within an individual, so we asked whether there are also overall differences in histone modifications between the brawny majors and the brainy minors that might alter specific features of the whole organism, such as behavior.”

In examining several different histone modifications, the team found a number of distinct differences between the major and minor castes. Simola states that the most notable modification, “both discriminates the two castes from each other and correlates well with the expression levels of different genes between the castes. And if you look at which genes are being expressed between these two castes, these genes correspond very nicely to the brainy versus brawny idea. In the majors we find that genes that are involved in muscle development are expressed at a higher level, whereas in the minors, many genes involved in brain development and neurotransmission are expressed at a higher level.”

These changes in histone modifications between ant castes are likely caused by a regulator gene, called CBP, that has “already been implicated in aspects of learning and behavior by genetic studies in mice and in certain human diseases,” Berger says. “The idea is that the same CBP regulator and histone modification are involved in a learned behavior in ants — foraging — mainly in the brainy minor caste, to establish a pattern of gene regulation that leads to neuronal patterning for figuring out where food is and being able to bring the food back to the nest.”

Simola notes that “we know from mouse studies that if you inactivate or delete the CBP regulator, it actually leads to significant learning deficits in addition to craniofacial muscular malformations. So from mammalian studies, it’s clear this is an important protein involved in learning and memory.”

These findings have established the crucial role of genome structure in general, and histone modifications in particular, in determining the acquisition of organism-level characteristics in ant castes. The research team is looking ahead to expand the work by manipulating the expression of the CBP regulator in ants to observe effects on caste development and behavior. They also hope to refine the technique of mapping histone modifications so that specific tissues, such as a brain from a single ant, can be analyzed, rather than using pooled samples, as in the current study.

Berger observes that all of the genes known to be major epigenetic regulators in mammals are conserved in ants, which makes them “a fantastic model for studying behavior and longevity. Ants provide an extraordinary opportunity to explore and understand the epigenetic processes that underlie many human diseases and the aging process.”

Berger is also the director of the Penn Epigenetics Program. The research was supported by a Howard Hughes Medical Institute Collaborative Innovation Award, a postdoctoral training grant from the Penn Department of Cell and Developmental Biology, and a postdoctoral fellowship from the Helen Hay Whitney Foundation.

Journal Reference:

  1. D. F. Simola, C. Ye, N. S. Mutti, K. Dolezal, R. Bonasio, J. Liebig, D. Reinberg, S. L. Berger. A chromatin link to caste identity in the carpenter ant Camponotus floridanusGenome Research, 2012; DOI:10.1101/gr.148361.112

Edward O. Wilson: The Riddle of the Human Species (N.Y.Times)

THE STONEFebruary 24, 2013, 7:30 pm

By EDWARD O. WILSON

The task of understanding humanity is too important and too daunting to leave to the humanities. Their many branches, from philosophy to law to history and the creative arts, have described the particularities of human nature with genius and exquisite detail, back and forth in endless permutations. But they have not explained why we possess our special nature and not some other out of a vast number of conceivable possibilities. In that sense, the humanities have not accounted for a full understanding of our species’ existence.

So, just what are we? The key to the great riddle lies in the circumstance and process that created our species. The human condition is a product of history, not just the six millenniums of civilization but very much further back, across hundreds of millenniums. The whole of it, biological and cultural evolution, in seamless unity, must be explored for an answer to the mystery. When thus viewed across its entire traverse, the history of humanity also becomes the key to learning how and why our species survived.

A majority of people prefer to interpret history as the unfolding of a supernatural design, to whose author we owe obedience. But that comforting interpretation has grown less supportable as knowledge of the real world has expanded. Scientific knowledge (measured by numbers of scientists and scientific journals) in particular has been doubling every 10 to 20 years for over a century. In traditional explanations of the past, religious creation stories have been blended with the humanities to attribute meaning to our species’s existence. It is time to consider what science might give to the humanities and the humanities to science in a common search for a more solidly grounded answer to the great riddle.

To begin, biologists have found that the biological origin of advanced social behavior in humans was similar to that occurring elsewhere in the animal kingdom. Using comparative studies of thousands of animal species, from insects to mammals, they have concluded that the most complex societies have arisen through eusociality — roughly, “true” social condition. The members of a eusocial group cooperatively rear the young across multiple generations. They also divide labor through the surrender by some members of at least some of their personal reproduction in a way that increases the “reproductive success” (lifetime reproduction) of other members.

Leif Parsons

Eusociality stands out as an oddity in a couple of ways. One is its extreme rarity. Out of hundreds of thousands of evolving lines of animals on the land during the past 400 million years, the condition, so far as we can determine, has arisen only about two dozen times. This is likely to be an underestimate, due to sampling error. Nevertheless, we can be certain that the number of originations was very small.

Furthermore, the known eusocial species arose very late in the history of life. It appears to have occurred not at all during the great Paleozoic diversification of insects, 350 to 250 million years before the present, during which the variety of insects approached that of today. Nor is there as yet any evidence of eusocial species during the Mesozoic Era until the appearance of the earliest termites and ants between 200 and 150 million years ago. Humans at the Homo level appeared only very recently, following tens of millions of years of evolution among the primates.

Once attained, advanced social behavior at the eusocial grade has proved a major ecological success. Of the two dozen independent lines, just two within the insects — ants and termites — globally dominate invertebrates on the land. Although they are represented by fewer than 20 thousand of the million known living insect species, ants and termites compose more than half of the world’s insect body weight.

The history of eusociality raises a question: given the enormous advantage it confers, why was this advanced form of social behavior so rare and long delayed? The answer appears to be the special sequence of preliminary evolutionary changes that must occur before the final step to eusociality can be taken. In all of the eusocial species analyzed to date, the final step before eusociality is the construction of a protected nest, from which foraging trips begin and within which the young are raised to maturity. The original nest builders can be a lone female, a mated pair, or a small and weakly organized group. When this final preliminary step is attained, all that is needed to create a eusocial colony is for the parents and offspring to stay at the nest and cooperate in raising additional generations of young. Such primitive assemblages then divide easily into risk-prone foragers and risk-averse parents and nurses.

Leif Parsons

What brought one primate line to the rare level of eusociality? Paleontologists have found that the circumstances were humble. In Africa about two million years ago, one species of the primarily vegetarian australopithecine evidently shifted its diet to include a much higher reliance on meat. For a group to harvest such a high-energy, widely dispersed source of food, it did not pay to roam about as a loosely organized pack of adults and young like present-day chimpanzees and bonobos. It was more efficient to occupy a campsite (thus, the nest) and send out hunters who could bring home meat, either killed or scavenged, to share with others. In exchange, the hunters received protection of the campsite and their own young offspring kept there.

From studies of modern humans, including hunter-gatherers, whose lives tell us so much about human origins, social psychologists have deduced the mental growth that began with hunting and campsites. A premium was placed on personal relationships geared to both competition and cooperation among the members. The process was ceaselessly dynamic and demanding. It far exceeded in intensity anything similar experienced by the roaming, loosely organized bands of most animal societies. It required a memory good enough to assess the intentions of fellow members, to predict their responses, from one moment to the next; and it resulted in the ability to invent and inwardly rehearse competing scenarios of future interactions.

The social intelligence of the campsite-anchored prehumans evolved as a kind of non-stop game of chess. Today, at the terminus of this evolutionary process, our immense memory banks are smoothly activated across the past, present, and future. They allow us to evaluate the prospects and consequences variously of alliances, bonding, sexual contact, rivalries, domination, deception, loyalty and betrayal. We instinctively delight in the telling of countless stories about others as players upon the inner stage. The best of it is expressed in the creative arts, political theory, and other higher-level activities we have come to call the humanities.

The definitive part of the long creation story evidently began with the primitive Homo habilis (or a species closely related to it) two million years ago. Prior to the habilines the prehumans had been animals. Largely vegetarians, they had human-like bodies, but their cranial capacity remained chimpanzee-size, at or below 500 cubic centimeters. Starting with the habiline period the capacity grew precipitously: to 680 cubic centimeters in Homo habilis, 900 in Homo erectus, and about 1,400 in Homo sapiens. The expansion of the human brain was one of the most rapid episodes of evolution of complex organs in the history of life.


Still, to recognize the rare coming together of cooperating primates is not enough to account for the full potential of modern humans that brain capacity provides. Evolutionary biologists have searched for the grandmaster of advanced social evolution, the combination of forces and environmental circumstances that bestowed greater longevity and more successful reproduction on the possession of high social intelligence. At present there are two competing theories of the principal force. The first is kin selection: individuals favor collateral kin (relatives other than offspring) making it easier for altruism to evolve among members of the same group. Altruism in turn engenders complex social organization, and, in the one case that involves big mammals, human-level intelligence.

The second, more recently argued theory (full disclosure: I am one of the modern version’s authors), the grandmaster is multilevel selection. This formulation recognizes two levels at which natural selection operates: individual selection based on competition and cooperation among members of the same group, and group selection, which arises from competition and cooperation between groups. Multilevel selection is gaining in favor among evolutionary biologists because of a recent mathematical proof that kin selection can arise only under special conditions that demonstrably do not exist, and the better fit of multilevel selection to all of the two dozen known animal cases of eusocial evolution.

The roles of both individual and group selection are indelibly stamped (to borrow a phrase from Charles Darwin) upon our social behavior. As expected, we are intensely interested in the minutiae of behavior of those around us. Gossip is a prevailing subject of conversation, everywhere from hunter-gatherer campsites to royal courts. The mind is a kaleidoscopically shifting map of others, each of whom is drawn emotionally in shades of trust, love, hatred, suspicion, admiration, envy and sociability. We are compulsively driven to create and belong to groups, variously nested, overlapping or separate, and large or small. Almost all groups compete with those of similar kind in some manner or other. We tend to think of our own as superior, and we find our identity within them.

The existence of competition and conflict, the latter often violent, has been a hallmark of societies as far back as archaeological evidence is able to offer. These and other traits we call human nature are so deeply resident in our emotions and habits of thought as to seem just part of some greater nature, like the air we all breathe, and the molecular machinery that drives all of life. But they are not. Instead, they are among the idiosyncratic hereditary traits that define our species.

The major features of the biological origins of our species are coming into focus, and with this clarification the potential of a more fruitful contact between science and the humanities. The convergence between these two great branches of learning will matter hugely when enough people have thought it through. On the science side, genetics, the brain sciences, evolutionary biology, and paleontology will be seen in a different light. Students will be taught prehistory as well as conventional history, the whole presented as the living world’s greatest epic.

We will also, I believe, take a more serious look at our place in nature. Exalted we are indeed, risen to be the mind of the biosphere without a doubt, our spirits capable of awe and ever more breathtaking leaps of imagination. But we are still part of earth’s fauna and flora. We are bound to it by emotion, physiology, and not least, deep history. It is dangerous to think of this planet as a way station to a better world, or continue to convert it into a literal, human-engineered spaceship. Contrary to general opinion, demons and gods do not vie for our allegiance. We are self-made, independent, alone and fragile. Self-understanding is what counts for long-term survival, both for individuals and for the species.

Edward O. Wilson is Honorary Curator in Entomology and University Research Professor Emeritus, Harvard University. He has received more than 100 awards for his research and writing, including the U. S. National Medal of Science, the Crafoord Prize and two Pulitzer Prizes in non-fiction. His most recent book is “The Social Conquest of Earth.”

*   *   *

Interview with Edward O. Wilson: The Origin of Morals (Spiegel)

February 26, 2013 – 01:23 PM

By Philip Bethge and Johann Grolle

American sociobiologist Edward O. Wilson is championing a controversial new approach for explaining the origins of virtue and sin. In an interview, the world-famous ant reseacher explains why he believes the inner struggle is the characteristic trait of human nature.

Edward O. Wilson doesn’t come across as the kind of man who’s looking to pick a fight. With his shoulders upright and his head tilting slightly to the side, he shuffles through the halls of Harvard University. His right eye, which has given him trouble since his childhood, is halfway closed. The other is fixed on the ground. As an ant researcher, Wilson has made a career out of things that live on the earth’s surface.

There’s also much more to Wilson. Some consider him to be the world’s most important living biologist, with some placing him on a level with Charles Darwin.

In addition to discovering and describing hundreds of species of ants, Wilson’s book on this incomparably successful group of insects is the only non-fiction biology tome ever to win a Pulitzer Prize. Another achievement was decoding the chemical communication of ants, whose vocabulary is composed of pheromones. His study of the ant colonization of islands helped to establish one of the most fruitful branches of ecology. And when it comes to the battle against the loss of biodiversity, Wilson is one of the movement’s most eloquent voices.

‘Blessed with Brilliant Enemies’

But Wilson’s fame isn’t solely the product of his scientific achievements. His enemies have also helped him to establish a name. “I have been blessed with brilliant enemies,” he says. In fact, the multitude of scholars with whom Wilson has skirmished academically is illustrious. James Watson, one of the discoverers of the double helix in DNA is among them, as is essayist Stephen Jay Gould.

At 83 years of age, Wilson is still at work making a few new enemies. The latest source of uproar is a book, “The Social Conquest of Earth,” published last April in the United States and this month in a German-language edition. In the tome, Wilson attempts to describe the triumphal advance of humans in evolutionary terms.

It is not uncommon for Wilson to look to ants for inspiration in his writings — and that proves true here, as well. When, for example, he recalls beholding two 90-million-year-old worker ants that were trapped in a piece of fossil metasequoia amber as being “among the most exciting moments in my life,” a discovery that “ranked in scientific importance withArchaeopteryx, the first fossil intermediary between birds and dinosaurs, and Australopithecus, the first ‘missing link’ discovered between modern humans and the ancestral apes.”

But that’s all just foreplay to the real controversy at the book’s core. Ultimately, Wilson uses ants to explain humans’ social behavior and, by doing so, breaks with current convention. The key question is the level at which Darwinian selection of human characteristics takes place. Did individuals enter into a fight for survival against each other, or did groups battle it out against competing groups?

Prior to this book, Wilson had been an influential champion of the theory of kin selection. He has now rejected his previous teachings, literally demolishing them. “The beautiful theory never worked well anyway, and now it has collapsed,” he writes. Today, he argues that human nature can only be understood if it is perceived as being the product of “group selection” — a view that Wilson’s fellow academics equate with sacrilege. They literally lined up to express their scientific dissent in a joint letter.

Some of the most vociferous criticism has come from Richard Dawkins, whose bestselling 1976 book “The Selfish Gene” first introduced the theory of kin selection to a mass audience. In a withering review of Wilson’s book in Britain’s Prospect magazine, Dawkins accuses a man he describes as his “lifelong hero” of “wanton arrogance” and “perverse misunderstandings”. “To borrow from Dorothy Parker,” he writes, “this is not a book to be tossed lightly aside. It should be thrown with great force.”

SPIEGEL recently sat down with sociobiologist Wilson to discuss his book and the controversy surrounding it.

SPIEGEL: Professor Wilson, lets assume that 10 million years ago some alien spacecraft had landed on this planet. Which organisms would they find particularly intriguing?

Wilson: Their interest, I believe, would not have been our ancestors. Primarily, they would have focused on ants, bees, wasps, and termites. Their discovery is what the aliens would report back to headquarters.

SPIEGEL: And you think those insects would be more interesting to them than, for example, elephants, flocks of birds or intelligent primates?

Wilson: They would be, because, at that time, ants and termites would be the most abundant creatures on the land and the most highly social creatures with very advanced division of labor and caste. We call them “eusocial,” and this phenomenon seems to be extremely rare.

SPIEGEL: What else might the aliens consider particularly interesting about ants?

Wilson: Ants engage in farming and animal husbandry. For example, some of them cultivate fungi. Others herd aphids and literally milk them by stroking them with their antennae. And the other thing the aliens would find extremely interesting would be the degree to which these insects organize their societies by pheromones, by chemical communication. Ants and termites have taken this form of communication to extremes.

SPIEGEL: So the aliens would cable back home: “We have found ants. They are the most promising candidates for a future evolution towards intelligent beings on earth?”

Wilson: No, they wouldn’t. They would see that these creatures were encased in exoskeletons and therefore had to remain very small. They would conclude that there was little chance for individual ants or termites to develop much reasoning power, nor, as a result, the capacity for culture. But at least on this planet, you have to be big in order to have sufficient cerebral cortex. And you probably have to be bipedal and develop hands with pulpy fingers, because those give you the capacity to start creating objects and to manipulate the environment.

SPIEGEL: Would our ancestors not have caught their eye?

Wilson: Ten million years ago, our ancestors indeed had developed a somewhat larger brain and versatile hands already. But the crucial step had yet to come.

SPIEGEL: What do you mean?

Wilson: Let me go back to the social insects for a moment. Why did social insects start to form colonies? Across hundreds of millions of years, insects had been proliferating as solitary forms. Some of them stayed with their young for a while, guided them and protected them. You find that widespread but far from universal in the animal kingdom. However, out of those species came a much smaller number of species who didn’t just protect their young, but started building nests that they defended …

SPIEGEL: … similar to birds.

Wilson: Yes. And I think that birds are right at the threshold of eusocial behaviour. But looking at the evolution of ants and termites again, there is another crucial step. In an even smaller group, the young don’t only grow up in their nest, but they also stay and care for the next generation. Now you have a group staying together with a division of labor. That is evidently the narrow channel of evolution that you have to pass through in order to become eusocial.

SPIEGEL: And our ancestors followed the same path?

Wilson: Yes. I argue that Homo habilis, the first humans, also went through these stages. In particular, Homo habilis was unique in that they already had shifted to eating meat.

SPIEGEL: What difference would that make?

Wilson: When animals start eating meat, they tend to form packs and to divide labor. We know that the immediate descendants of Homo habilis, Homo erectus, gathered around camp sites and that they actually had begun to use fire. These camp sites are equivalent to nests. That’s where they gathered in a tightly knit group, and then individuals went out searching for food.

SPIEGEL: And this development of groups drives evolution even further?

Wilson: Exactly. And, for example, if it now comes to staking out the hunting grounds, then group stands against group.

SPIEGEL: Meaning that this is the origin of warfare?

Wilson: Yes. But it doesn’t take necessarily the forming of an army or a battalion and meeting on the field and fighting. It was mostly what you call “vengeance raids”. One group attacks another, maybe captures a female or kills one or two males. The other group then counterraids, and this will go back and forth, group against group.

SPIEGEL: You say that this so called group selection is vital for the evolution of humans. Yet traditionally, scientists explain the emergence of social behavior in humans by kin selection.

Wilson: That, for a number of reasons, isn’t much good as an explanation.

SPIEGEL: But you yourself have long been a proponent of this theory. Why did you change your mind?

Wilson: You are right. During the 1970s, I was one of the main proponents of kin selection theory. And at first the idea sounds very reasonable. So for example, if I favored you because you were my brother and therefore we share one half of our genes, then I could sacrifice a lot for you. I could give up my chance to have children in order to get you through college and have a big family. The problem is: If you think it through, kin selection doesn’t explain anything. Instead, I came to the conclusion that selection operates on multiple levels. On one hand, you have normal Darwinian selection going on all the time, where individuals compete with each other. In addition, however, these individuals now form groups. They are staying together, and consequently it is group versus group.

SPIEGEL: Turning away from kin selection provoked a rather fierce reaction from many of your colleagues.

Wilson: No, it didn’t. The reaction was strong, but it came from a relatively small group of people whose careers are based upon studies of kin selection.

SPIEGEL: Isn’t that too easy? After all, 137 scientists signed a response to your claims. They accuse you of a “misunderstanding of evolutionary theory”.

Wilson: You know, most scientists are tribalists. Their lives are so tied up in certain theories that they can’t let go.

SPIEGEL: Does it even make a substantial difference if humans evolved through kin selection or group selection?

Wilson: Oh, it changes everything. Only the understanding of evolution offers a chance to get a real understanding of the human species. We are determined by the interplay between individual and group selection where individual selection is responsible for much of what we call sin, while group selection is responsible for the greater part of virtue. We’re all in constant conflict between self-sacrifice for the group on the one hand and egoism and selfishness on the other. I go so far as to say that all the subjects of humanities, from law to the creative arts are based upon this play of individual versus group selection.

SPIEGEL: Is this Janus-faced nature of humans our greatest strength at the end of the day?

Wilson: Exactly. This inner conflict between altruism and selfishness is the human condition. And it is very creative and probably the source of our striving, our inventiveness and imagination. It’s that eternal conflict that makes us unique.

SPIEGEL: So how do we negotiate this conflict?

Wilson: We don’t. We have to live with it.

SPIEGEL: Which element of this human condition is stronger?

Wilson: Let’s put it this way: If we would be mainly influenced by group selection, we would be living in kind of an ant society.

SPIEGEL: … the ultimate form of communism?

Wilson: Yes. Once in a while, humans form societies that emphasize the group, for example societies with Marxist ideology. But the opposite is also true. In other societies the individual is everything. Politically, that would be the Republican far right.

SPIEGEL: What determines which ideology is predominant in a society?

Wilson: If your territory is invaded, then cooperation within the group will be extreme. That’s a human instinct. If you are in a frontier area, however, then we tend to move towards the extreme individual level. That seems to be a good part of the problem still with America. We still think we’re on the frontier, so we constantly try to put forward individual initiative and individual rights and rewards based upon individual achievement.

SPIEGEL: Earlier, you differentiated between the “virtue” of altruism and the “sin” of individualism. In your book you talk about the “poorer and the better angels” of human nature. Is it helpful to use this kind of terminology?

Wilson: I will admit that using the terminology of “virtue” and “sin” is what poets call a “trope”. That is to say, I wanted the idea in crude form to take hold. Still, a lot of what we call “virtue” has to do with propensities to behave well toward others. What we call “sin” are things that people do mainly out of self-interest.

SPIEGEL: However, our virtues towards others go only so far. Outside groups are mainly greeted with hostility.

Wilson: You are right. People have to belong to a group. That’s one of the strongest propensities in the human psyche and you won’t be able to change that. However, I think we are evolving, so as to avoid war — but without giving up the joy of competition between groups. Take soccer …

SPIEGEL: … or American football.

Wilson: Oh, yes, American football, it’s a blood sport. And people live by team sports and national or regional pride connected with team sports. And that’s what we should be aiming for, because, again, that spirit is one of the most creative. It landed us on the moon, and people get so much pleasure from it. I don’t want to see any of that disturbed. That is a part of being human. We need our big games, our team sports, our competition, our Olympics.

SPIEGEL: “Humans,” the saying goes, “have Paleolithic emotions” …

Wilson: … “Medieval institutions and god-like technology”. That’s our situation, yeah. And we really have to handle that.

SPIEGEL: How?

Wilson: So often it happens that we don’t know how, also in situations of public policy and governance, because we don’t have enough understanding of human nature. We simply haven’t looked at human nature in the best way that science might provide. I think what we need is a new Enlightenment. During the 18th century, when the original Enlightenment took place, science wasn’t up to the job. But I think science is now up to the job. We need to be harnessing our scientific knowledge now to get a better, science-based self-understanding.

SPIEGEL: It seems that, in this process, you would like to throw religions overboard altogether?

Wilson: No. That’s a misunderstanding. I don’t want to see the Catholic Church with all of its magnificent art and rituals and music disappear. I just want to have them give up their creation stories, including especially the resurrection of Christ.

SPIEGEL: That might well be a futile endeavour …

Wilson: There was this American physiologist who was asked if Mary’s bodily ascent from Earth to Heaven was possible. He said, “I wasn’t there; therefore, I’m not positive that it happened or didn’t happen; but of one thing I’m certain: She passed out at 10,000 meters.” That’s where science comes in. Seriously, I think we’re better off with no creation stories.

SPIEGEL: With this new Enlightenment, will we reach a higher state of humanity?

Wilson: Do we really want to improve ourselves? Humans are a very young species, in geologic terms, and that’s probably why we’re such a mess. We’re still living with all this aggression and ability to go to war. But do we really want to change ourselves? We’re right on the edge of an era of being able to actually alter the human genome. But do we want that? Do we want to create a race that’s more rational and free of many of these emotions? My response is no, because the only thing that distinguishes us from super-intelligent robots are our imperfect, sloppy, maybe even dangerous emotions. They are what makes us human.

SPIEGEL: Mr. Wilson, we thank you for this conversation.

Interview conducted by Philip Bethge and Johann Grolle

Argentine Invasion (Radiolab)

Monday, July 30, 2012 – 10:00 PM

From a suburban sidewalk in southern California, Jad and Robert witness the carnage of a gruesome turf war. Though the tiny warriors doing battle clock in at just a fraction of an inch, they have evolved a surprising, successful, and rather unsettling strategy of ironclad loyalty, absolute intolerance, and brutal violence.

Drawing of an Argentinte Ant

(Adam Cole/WNYC)

David Holway, an ecologist and evolutionary biologist from UC San Diego, takes us to a driveway in Escondido, California where a grisly battle rages. In this quiet suburban spot, two groups of ants are putting on a chilling display of dismemberment and death. According to David, this battle line marks the edge of an enormous super-colony of Argentine ants. Think of that anthill in your backyard, and stretch it out across five continents.

Argentine ants are not good neighbors. When they meet ants from another colony, any other colony, they fight to the death, and tear the other ants to pieces. While other kinds of ants sometimes take slaves or even have sex with ants from different colonies, the Argentine ants don’t fool around. If you’re not part of the colony, you’re dead.

According to evolutionary biologist Neil Tsutsui and ecologist Mark Moffett, the flood plains of northern Argentina offer a clue as to how these ants came to dominate the planet. Because of the frequent flooding, the homeland of Linepithema humile is basically a bootcamp for badass ants. One day, a couple ants from one of these families of Argentine ants made their way onto a boat and landed in New Orleans in the late 1800s. Over the last century, these Argentine ants wreaked havoc across the southern U.S. and a significant chunk of coastal California.

In fact, Melissa Thomas, an Australian entomologist, reveals that these Argentine ants are even more well-heeled than we expected – they’ve made to every continent except Antarctica. No matter how many thousands of miles separate individual ants, when researchers place two of them together – whether they’re plucked from Australia, Japan, Hawaii … even Easter Island – they recognize each other as belonging to the same super-colony.

But the really mind-blowing thing about these little guys is the surprising success of their us-versus-them death-dealing. Jad and Robert wrestle with what to make of this ant regime, whether it will last, and what, if anything, it might mean for other warlike organisms with global ambitions.