Anthropology.net

Fellow blogger, Simon Greenhill of HENRY, and co-authors published a cool paper evaluating language evolution that just came out in today’s issue of Science. The premise behind the paper, “Languages Evolve in Punctuational Bursts,” is simple to follow. By comparing related versions, or homologs, of common words between the following language families: Indo-European, Bantu, and Austronesian, changes in languages can be tracked through the fate of certain words, just as mutations in key genes can tell a species’ history.

The team selected the homologous words from a Swadesh list, one of several linguistic lists of vocabulary where the words have “basic.” Swadesh lists are used is used in lexicostatistics, a way of quantitative language relatedness assessment as well as glottochronology, a method to assess and date language divergence dating. Swadesh lists were used in this study because they are changed very little over time and are rarely borrowed, making them good clues about how one language relates to another.

In my own head, I’ve built my own set of Swadesh lists and compared them to languages I’ve come across. I wish I thought about making some sort of formal study out of my observations. I guess Simon et al. beat me to the punch! Here’s a couple of examples from a cross Indo-European language family comparison that I’ve conjured up…. The words for father and mother in English, Spanish padre and madre, Farsi (Persian) pedar and madar. Despite many borrowings, English the much younger languages is much phonetically different from Latin languages in this example, and even more derived from the Farsi homologs.

Using this sort of comparative vocabulary data, Simon et al. were able to construct phylogenetic trees to show how new languages sprouted from root languages. Furthermore, applying the same mathematical models that showed that biological speciation can occur in bursts, to language to conclude that lineages with many “nodes,” or offshoots, change faster over time than language families that have few offshoots. And most of this acceleration occurs right around time the new languages separated from their ancestral lines.

I love these sorts of comparisons, especially because punctuated equilibria is fresh on my mind. As recent as last week has there been an explosion of discussion on punctuated equilibrium on Sandwalk, the Loom and Greg Laden’s blog. But anyways, I must hand it to Simon Greenhill and his coauthors who gracefully integrated an evolutionary biological concept into a linguistic anthropological scope. It really doesn’t matter whether the replicators are genes or words, the same approaches can be used to analyze the data and explain the model.

One last thing, do read Simon’s blog post describing his project and involvement as well as the Nature News coverage on the paper.

Atkinson, Q.D., Meade, A., Venditti, C., Greenhill, S.J., Pagel, M. (2008). Languages Evolve in Punctuational Bursts. Science, 319(5863), 588-588. DOI: 10.1126/science.1149683

If you don’t follow my other blog but are interested in tool use, I just blogged about gorillas who have been seen using clumps of grass and branches as weapons as well as the new research which links macaque tool use and mirror neurons at Primatology.net.

John Hawks also covered the macaque & mirror neuron linkage too, so check out his write up too!

I’ve got a couple pseudo-science, evolutionary psychological news bits to share with you. The first is coverage of Alan Harvey music evolutionary theory that he presented at the Annual Australian Neuroscience Meeting. From the article,

“[Alan Harvey] says music is not just a pretty sound, but also a way of communicating that is just as important as language… [and] music has been central to the evolution of the modern mind.”

I really can’t think of a way to go about proving that the ability to make and appreciate music has been positively selected in humans. In Harvey’s mind, the reason why we see music in all human cultures is indicative of its selective advantage. But that’s not convincing enough for me.

I’ve been thinking about ways to show scientific basis for this hypothesis. Perhaps comparing and contrasting activity in the auditory association area of the brain, the Wernicke’s area, in the temporal lobes of different non-human primates and humans from different cultural backgrounds subjected to music will elucidate how much more activity is required to process and associate music. Anyways, that’s just one possible experiment. The rest of Harvey’s thoughts are summarized in this 2006 transcript, “History of language and music in humans,” where he mentions the book, “The Singing Neanderthals.”

To be really honest, I know little about the music throughout human evolution. The aptly titled book, “The Origins of Music” or this paper, “Music, Cognition, Culture, and Evolution,” maybe a nice place to start informing myself of this topic. I think one of our frequent commenters, Victor Grauer, will do better justice if he decides to cover this news bit.

The next pseudo-scientific topic is about, “what evolution can say about why humans kill — and about why we do so less than we used to?”

I feel as if this topic has been talked about ad nauseam, so I really don’t know why I’m giving it special coverage. I guess its because I find the ‘homicide adaptation theory’ the article describes as a dumbed-down reiteration of game theory, the theory that says individuals will choose strategies that will maximize their return. Here’s what’s actually said of the the ‘homicide adaptation theory’ from the book “The Innate Mind,”

“The theory proposes that, over evolutionary history, humans have repeatedly encountered a wide range of situations in which the benefits of killing another person outweighed the costs — particularly when the assessed costs of murder are low, success is likely and other non-lethal options have been closed off.”

The article goes on to describe the violence we see in non-human primates and compare that to human violence behavior. There’s also a run down on the history of violence. Some discussion is given to concept, the culture of violence.

I think these two news bits aren’t incredibly insightful but they are interesting topics to think about. How can one go about explaining behaviors as beneficial adaptations? I don’t wanna rehash the argument behind sociobiology as an adaptionist program, because Lewontin did a great job addressing this shortcoming in sociobiological/evolutionary psychological thinking… But I can’t help but to think, why do these behaviors have to be considered through an adaptive framework? In other words, why can’t these behaviors just be features of being human?