Just read about an article on phoneme diversity via GNXP and Babel’s Dawn. Hopefully I’ll share some of my thoughts on the paper this weekend as it clearly ties in with work I’m currently doing (see here and here). Below is the abstract:
Human genetic and phenotypic diversity declines with distance from Africa, as predicted by a serial founder effect in which successive population bottlenecks during range expansion progressively reduce diversity, underpinning support for an African origin of modern humans. Recent work suggests that a similar founder effect may operate on human culture and language. here I show that the number of phonemes used in a global sample of 504 languages is also clinal and fits a serial founder-effect model of expansion from an inferred origin in Africa. This result, which is no explained by more recent demographic history, local language diversity, or statistical non-independence within language families, points to parallel mechanisms shaping genetic and linguistic diversity and supports an African origin of modern human languages.
Reference: Atkinson, Q.D (2011). Phonemic Diversity Supports a Serial Founder Effect Model of Language Expansion from Africa. Science 332, 346. DOI: 10.1126/science.1199295.
There is disagreement about whether human political evolution has proceeded through a sequence of incremental increases in complexity, or whether larger, non-sequential increases have occurred. The extent to which societies have decreased in complexity is also unclear. These debates have continued largely in the absence of rigorous, quantitative tests. We evaluated six competing models of political evolution in Austronesian-speaking societies using phylogenetic methods. Here we show that in the best-fitting model political complexity rises and falls in a sequence of small steps. This is closely followed by another model in which increases are sequential but decreases can be either sequential or in bigger drops. The results indicate that large, non-sequential jumps in political complexity have not occurred during the evolutionary history of these societies. This suggests that, despite the numerous contingent pathways of human history, there are regularities in cultural evolution that can be detected using computational phylogenetic methods. [My emphasis].
I don’t have much to add on the subject as I think Razib covered most of the relevant points, plus I haven’t even finished reading the paper yet (I’m hoping to get back into research blogging later this week). I will, however, post one of their figures that shows the dynamic between the rise and fall of political complexity, and how it shows regularity (btw, RJMCMC means Bayesian reversible-jump Markov chain Monte Carlo… if that helps you in any way):
Speaking in Tones: Music and Language Partner in the brain. The first of two really good articles in Scientific American. As you can guess by the title, this article is looking at current research into the links between music and language, such as the overlap in brain circuitry, how prosodic qualities of speech are vital in language development, and the way in which a person hears a set of musical notes may be affected by their native language. Sadly, the article is behind a paywall, so unless you have a subscription you’ll only get to read the first few paragraphs, plus the one I’m about to quote:
In a 2007 investigation neuroscientists Patrick Wong and Nina Kraus, along with their colleagues at Northwestern University, exposed English speakers to Mandarin speech sounds and measured the electrical responses in the auditory brain stem using electrodes placed on the scalp. The responses to Mandarin were stronger among participants who had received musical training — and the earlier they had begun training and the longer they had continued training, the stronger the activity in these brain areas.
Our hypothesis involves the unintended consequences of aesthetic and perceptual laws that evolved to help creatures quickly identify what in their surroundings is useful (food and potential mates) and what constitutes a threat (environment dangers and predators). We believe that these laws indirectly drive many aspects of the evolution of animals’ shape, size and coloration.
It’s important to note that they are not arguing against natural selection; rather, they are simply offering an addition force that guides the evolution of a species. It’s quite interesting, even if I’m not completely convinced by their hypothesis — but my criticisms can wait until they publish an actual academic paper on the subject.
A robotic model of the human vocal tract?Talking Brains links to the Anthropomorphic Talking Robot developed at Waseda University. Apparently it can produce some vowels. Here is a picture of the device (which looks like some sort of battle drone):
Battle Drone or Model Vocal Tract?
Y Chromosome II: What is its structure?Be sure to check out the new contributor over at GNXP, Kele Cable, and her article on the structure of the Y Chromosome. I found this sentence particularly amusing:
As you can see in Figure 1, the Y chromosome (on the right) is puny and diminutive. It really is kind of pathetic once you look at it.
Scientopia. A cool collection of bloggers have banded together to form Scientopia. With plenty of articles having already appeared it all looks very promising. In truth, it’s probably not going to be as successful as ScienceBlogs, largely because it doesn’t pay contributors and, well, nothing is ever going to be as big as ScienceBlogs was at its peak. This new ecology of the science blogosphere is well articulated in a long post by Bora over at A Blog Around the Clock.
Universal Grammar haters. Mark Lieberman takes umbrage with claims that Ewa Dabrowska’s recent work challenges the concept of a biologically evolved substrate for language. Put simply: it doesn’t. What their experiments suggest is that there are considerable differences in native language attainment. As some of you will probably know, I’m not necessarily a big fan of most UG conceptions, however, there are plenty of papers that directlydeal with suchissues. Dabrowska’s not being one of them. In Lieberman’s own words:
In support of this view, let me offer another analogy. Suppose we find that deaf people are somewhat more likely than hearing people to remember the individual facial characteristics of a stranger they pass on the street. This would be an interesting result, but would we spin it to the world as a challenge to the widely-held theory that there’s an evolutionary substrate for the development of human face-recognition abilities?
Remote control neurons. I remember reading about optogenetics awhile back. It’s a clever technique that enables neural manipulation through the use of light-activated channels and enzymes. Kevin Mitchell over at GNXP classic refers to a new approach where neurons are activated using a radio frequency magnetic field. The obvious advantage to this new approach being fairly straight-forward: magnetic-fields pass through brains far more easily than light. It means the new approach is a lot less invasive, without the need to insert micro-optical fibres or light-emitting diodes. Cool stuff.
According to these results, then, the simple action of squeezing the ball not only slowed down the participants’ naming of tools, but also slightly reduced their accuracy in naming them correctly. This occured, the authors say, because squeezing the ball involves the same motor circuits needed for generating the simulation, so it interferes with the brain’s ability to generate the mental image of reaching out and grasping the tool. This in turn slows identification of the tools, because their functionality is an integral component of our conceptualization of them. There is other evidence that parallel motor simulations can interfere with movements, and with each other: when reaching for a pencil, people have a larger grip aperture if a hammer is also present than if the pencil is by itself.
On the Origin of Science Writers. If you fancy yourself as a science writer, then Ed Yong, of Not Exactly Rocket Science, wants to read your story. As expected, he’s got a fairly large response (97 comments at the time of writing), which includes some of my favourite science journalists and bloggers. It’s already a useful resource, full of fascinating stories and bits of advice, from a diverse source of individuals.
Some thoughts about science blog aggregation. Although it’s still hanging about, many people, including myself, are looking for an alternative to the ScienceBlogs network. Dave Munger points to Friendfeed as one potential solution, with him setting up a feed for all the Anthropology posts coming in from Research Blogging. Also, in the comments Christina Pikas mentioned Nature Blogs, which, I’m ashamed to say, I haven’t come across before.
New developments in AI. An in-depth article on artificial intelligence over at .CSV. I’m only half-way through the article, but I thought it was worth mention as, the first half at least, is pretty good. H/T: Mind Hacks.
Many English Speakers cannot understand basic grammar. Apparently, “Research into grammar by academics at Northumbria University suggests that a significant proportion of native English speakers are unable to understand some basic sentences”. Language Log and John Hawks have both picked up on the story. Once the paper is released I’ll probably write an in-depth post at GNXP.
Birth Months of World Cup Players. A short, but interesting, post over at GNXP debunking the relevance of your birth month in regards to sporting achievement. I never thought there was any controversy over the issue… But it turns out I was wrong.
Just a quick note: I’m now also blogging over at Gene Expression. It’s actually pretty worthless note, considering the vast body of my visitors are equally divided between those arriving from GNXP and those using the search term Titanoboa. Still, the main point is that I’ll still be updating the site alongside my writings over at GNXP. Sadly for you Titanoboa fans I will be keeping snake-related posts to an absolute minimum.
Science Daily claims: Simple math explains dramatic beak shape variation in Darwin’s finches. Key paragraph: “Using digitization techniques, the researchers found that 14 distinct beak shapes, that at first glance look unrelated, could be categorized into three broader, group shapes. Despite the striking variety of sizes and shapes, mathematically, the beaks within a particular group only differ by their scales.”
Be sure to check out the Kahn Academy — a not-for-profit organisation that provides some great educational resources. For those of you interested in demographics and the quantitative analysis of movement, then here’s a whole section on differential equations.
How reliable are fMRI results? Another question I’m not so sure about. However, Prefrontal.org has a full paper on providing something of an answer. The key sentence: “the results from fMRI research may be somewhat less reliable than many researchers implicitly believe.”
Lastly, Jeff Elman, UCSD professor of cognitive science and co-director of the Kavli Institute for Brain and Mind, presents a lecture on some of the latest research in our ability to use language and why it is so far removed from other animal communication systems: