HENRY

National Geographic reeports that:

One of the world’s rarest creatures, Attenborough’s long-beaked echidna, appears to be alive and well, conservationists say. It is also reportedly quite delicious.

Echidna, Feared Extinct, Is Alive and “Tasty,” Hunters Tell Scientists

Languages have often been used to judge people, and a series of experiments by Kinzler et al, the native language of social cognition (doi:10.1073/pnas.0705345104), shows that this prejudice emerges early in development.

To start with, the authors showed a group of 5-6 month old infants two videos of adult females speaking American English. In the second video, however, the sound was played backwards. Despite the reversed speech having a similar temporal structure and sound spectrum, the infants preferred the “natural” speech condition.

They then did a similar experiment, but compared a video of American English to a video in Spanish. Once again, the infants (a new group of them), preferred to watch the person speaking in English - the language they were familiar with.

To test the effects of this bias on social interactions, the authors took a group of slightly older infants (10 months), and shown videos in English and French. Once the speaking was over, the ladies on the videos silently offered the infants a toy. Once again, the infants preferred the speakers of their own language, and tried to get the toy off them instead of the other speaker. So - the infants social interactions were heavily influenced by their language.

To follow this finding up, the authors took some young English-speaking children (5 years old), and showed them photographs of two unfamiliar children. The children then heard the unfamiliar children speak in French or English. When asked who they would rather be friends with, the children strongly preferred the child who spoke the same language as they did. Moreover, in another experiment, the authors showed that the children preferred speakers who had the same accent as them, over a speaker who spoke English, but had a different accent.

All in all, these results quite strongly point to an early developing social preference for speakers of the same language. Depressing, eh?

The Gileadites captured the fords of the Jordan leading
to Ephraim, and whenever a survivour of Ephraim said,
“Let me go over,” the men of Gilead asked him, “Are
you an Ephraimite?” If he replied, “No,” they said, “All
right, say Shibboleth.” If he said, “Sibboleth,” because
he could not pronounce the word correctly, they seized
him and killed him at the fords of the Jordan. Forty-two
thousand Ephraimites were killed at that time.

Judges 12:5– 6.

Altruism is another one of those things that people have used to pretend that humans are unique. However, a brand spanking new paper in PLoS Biology today shows experimental evidence that chimpanzees spontaneously and repeatedly perform altruistic acts towards both humans and other chimps. The authors argue that:

Taken together, the current results indicate that the altruistic tendency seen in early human ontogeny did not evolve in humans de novo. The roots of human altruism may go deeper than previously thought, reaching as far back as the last common ancestor of humans and chimpanzees. Undoubtedly, humans are exceptional with respect to the breadth in which they help, displaying helping across diverse contexts already early in infancy. But, as demonstrated here, humans are not unique, because chimpanzees have the capacity to use a newly acquired skill to help a conspecific as well. This helping occurs spontaneously and repeatedly, even in a novel situation when no reward is expected and no previous rewarding could have trained them to act accordingly.

Awwww.. you can read more at PLoS  Biology: Spontaneous Altruism by Chimpanzees and Young Children (doi:10.1371/journal.pbio.0050184)

Back in business, with the new issue of PRS B. First up is Sampietro et al (doi:10.1098/rspb.2007.0465) who used phylogeographic analyses on mtDNA samples (HVRI) from 11 Neolithic remains from Granollers (Catalonia, northeast Spain) dating to around 5500 years ago. They found that their results were consistent with long-term genetic continuity in the Iberian peninsula since Neolithic times, and argue that this is indicative of a dual model of Neolithic spread in Europe: acculturation in Central Europe followed by demic diffusion (i.e. population spread) into southern Europe.

This is followed by an intriguing paper which uses “fractal network theory” to investigate the complex structure of hunter–gatherer social networks (doi:10.1098/rspb.2007.0564):

In nature, many different types of complex system form hierarchical, self-similar or fractal-like structures that have evolved to maximize internal efficiency. In this paper, we ask whether hunter-gatherer societies show similar structural properties. We use fractal network theory to analyse the statistical structure of 1189 social groups in 339 hunter-gatherer societies from a published compilation of ethnographies.

We show that population structure is indeed self-similar or fractal-like with the number of individuals or groups belonging to each successively higher level of organization exhibiting a constant ratio close to 4. Further, despite the wide ecological, cultural and historical diversity of hunter-gatherer societies, this remarkable self-similarity holds both within and across cultures and continents. We show that the branching ratio is related to density-dependent reproduction in complex environments and hypothesize that the general pattern of hierarchical organization reflects the self-similar properties of the networks and the underlying cohesive and disruptive forces that govern the flow of material resources, genes and non-genetic information within and between social groups.

Our results offer insight into the energetics of human sociality and suggest that human social networks self-organize in response to similar optimization principles found behind the formation of many complex systems in nature.

Finally, here’s another example of rapid evolution at work. This time, it’s butterflies (Hypolimnas bolina) in Samoa, who’ve developed a “suppressor” gene to defeat Wolbachia. For those of you who aren’t familiar with the creepiness that is Wolbachia, which is a bacteria that is passed along female insects. To help itself breed, it deliberately screw up sex ratios in host species (in this case by selectively aborting male fetuses) to help itself survive.

The outcome of this selective “pruning” by Wolbachia, meant that in 2001, males made up a grand total of 1% of the butterfly population. However, in the last 5 years, the number of males has shifted back to 40% of the population, as a result of strong selection for host suppressor genes in less than 10 generations.

The original paper is in Science: Extraordinary Flux in Sex Ratio (doi:10.1126/science.1143369) and the BBC has a nice article: Butterfly shows evolution at work.

The BBC is reporting that the number of moles a person has, is  a good indicator of how quickly they  age. Apparently, the more moles a person has, the longer their telomeres, and the slower their rate of ageing. It’s not all good news, however, mole-laden people have increased risks of skin cancers like melanoma.

More at BBC News…

More bulletpoints - since I’m still conferencing:

• John Hawks discusses a paper in Science, “Middle Paleolithic Assemblages from the Indian Subcontinent Before and After the Toba Super-Eruption”, that discounts the theory that the Mount Toba eruption wiped out the majority of the human population around 74,000 years ago.
• Semantic Compositions went to see the new Transformers movie, and, whilst he enjoyed himself, he was beset by niggling doubts about how Megatron learnt to speak English and discusses the evidence in light of standard language acquisition theories.
• Evolution in Action:
  

    It started with a biologist sitting on a grassy river bank in York, eating a sandwich. It ended in the discovery of a “scruffy little weed with no distinguishing features” that is the first new species to have been naturally created in Britain for more than 50 years.

• Q: How come no one knows where Genghis Khan is buried?

I’m currently in New Caledonia, at the 7th International Conference on Oceanic Linguistics, so can be considered away from keyboard (et sur la plage!), but here’s a few bullet-points to tide you over.

The biologists are still managing to poke holes in creationut Behe’s new book, Jerry Coyne goes another round, as well as the lies creationists are spreading about Haldane’s “dilemma”.

..and in, uh, urine related news:

Female mice make new brain cells when they detect a dominant male’s urine, researchers have found. The discovery gives a clue as to how the chemical messages shape their receiver’s taste in mates.

…more at Powerful urine is mind-altering

National Geographic has a shiny website up about the Genographic Project

Fi has a brief rundown on our cultural phylogenetics session at Evolution 2007, whilst those of you in England and near beaches (i.e. the crazy), should watch out for the arrival of the Rubber Ducky floatilla.