Should Mother Tongue be Father Tongue?

A new paper, published in Science last week, has reviewed some of the correlations which suggest that language change may be subject to sex-specific transmission. This has been discovered through looking at Y-chromosome DNA types. Modern male DNA (Y-Chromosome) is found to be the DNA from the population who originally spoke the language which has survived, whereas modern female DNA is often not the DNA of the population which spoke the language which has survived.

This evidence has come from, among others, a study by Chaubey (2011) with evidence for the Indian subcontinent. Austroasiatic languages are spoken by tribes with a high proportion of immigrant Y-chromosome DNA from East Asia, but with a high percentage of local female (mitochondrial) DNA. This pattern was also true of the Tibeto-Burman language family in northeastern India.

Other studies found matching correlations in Africa and found that Niger-Congo languages correlate with Y-Chromosome types, but the female DNA, which correlated more with geography (Wood et al. (2005) and de Filippo et al. (2011)).

Sex-biased language change can also be seen in the expansion of the Malayo-Polynesians in New Guinea. New Guinea has populations of Malayo-Polynesian speakers and also populations of Melanesian speakers. Malayo-Polynesian female DNA is about the same in both Malayo-Polynesian speaking areas and Melanesian speaking areas. However, the Malayo-Polynesian Y-Chromosome is found way more in the Malayo-Polynesian speaking areas than the Melanesian speaking areas.

This pattern is also seen in Iceland where the female DNA is mainly British, but the Y-chromosome is mainly Scandinavian. This follows the pattern because the Icelandic language is also Scandinavian.

Forster and Renfrew (authors of the Science paper) show that these findings complement studies such as Stoneking and Delfin who found that in East Asia, it is women who move after marriage rather than men. This means that if a man and woman migrate to a populated area their female offspring will move to other villages when married but their male offspring will remain static meaning that their language will stay in the same place as their Y-Chromosomes.

Is this the only mechanism at work when correlations of sex-specific language change can be seen? Others have hypothesized things such as farming and trade might be a factor. Groups of emigrating agriculturalists may also contribute where men outnumber women and take wives from the local community they were moving to. Men are also biologically capable of passing on and spreading about much more of their DNA than women can. It may also be the case that it is the father’s language rather than the mother’s which will be dominant within a family but I think more research would have to be done on this.

Interestingly the opposite correlation to the ones seen above is seen in Greenland where both the language and female DNA is Eskimo but the Y-Chromosome DNA is European.

Some Links #14: Can Robots create their own language?

Can Robots create their own language? Sean already mentioned this in the comments for a previous post. But as I’m a big fan of Luc Steels‘ work this video may as well go on the front page:

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.

Carried to extremes: How quirks of perception drive the evolution of species. In the second good article, which by the way is free to view, Ramachandran and Ramachandran propose another mechanism of evolution in regards to perception:

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.

What conclusions can we draw from Neanderthal DNA pt.2

ResearchBlogging.org4. Nuclear DNA: Forays into 3 billion base pairs

4.1 Before Vi-80

The Vindija-80 (Vi-80) specimen is an important find for geneticists: it yielded a minimally contaminated sample and provided those first steps into Neanderthal genomics.

Previously, attempts at retrieving ancient nuclear DNA sequences proved to be a notoriously difficult process, plagued with problems of degradation, contamination and chemical damage (Hofreiter et al., 2001). Researchers also need to contend with quantities of nuclear genome available: for every nuclear genome there are approximately several hundred mtDNAs (Green et al., 2008). The severity of these problems, especially contamination, is magnified through Neanderthal genetic similarity with humans (Green et al., 2006). This is troubling because nuclear DNA presents far less variability than mtDNA (Russell, 2002). As a result, huge stretches of nuclear sequences are required to find a significant number of polymorphisms (ibid). Such implications meant that discovering endogenous DNA sequences requires sifting through a large corpus of “[…] more than 70 Neanderthal bone and tooth samples from different sites in Europe and western Asia” (Green et al., 2006, pg. 331).

Continue reading “What conclusions can we draw from Neanderthal DNA pt.2”