Itetem ta humgopak...Altogether now!...

If you read the paper on musical diversity within and between cultures in todays Proc R Soc, you will search in vain for any idea of what the music actually sounds like. So I had a google. And then I had a totally unrigorous ponder on what I found (I also looked in vain for any proper coverage of this work).

Tom Rzeszutek and his colleagues analyse a corpus of folk songs from '16 Austronesian-speaking aboriginal populations from Taiwan and the northern Philippines'. These include the Paiwan...

Here's a snippet of a rather nice Paiwan love song

What does the fact that this sits so easily on the western ear say about musical diversity - perhaps that the total range of musical possibilities is actually quite small, and that cultures explore musical space (saturate diversity, if you like) quite quickly? Does this also mean that there's a lot of convergent evolution in music, with the same tricks popping up often in different cultures?

Here's another...

Sounds pretty similar to me.

They also analyse the songs of the Ifugao...

What does the fact that the people behind this arrangement can slather their aboriginal song in a jumbo helping of (country and) western cheese, but still recognize it as something Ifugao, say about the features of music that are most important in placing it in a certain culture? And what does the fact that music hybridizes so easily say about the generation and meaning of musical diversity?

The authors quantify the songs using a technique of their own invention called 'CantoCore', based on the cantometrics approach devised in the 1960s by the mighty Alan Lomax. CantoCore 'codes 26 characters related to song structure, including rhythm, pitch, syllable, texture and form'. They than measure the distance between songs by adapting a technique used to measure genetic distance - borrowing the tools of phylogenetics.

When they do this, they find that there's much more musical variation within cultures than between them. Within culture variation accounts for a whopping 98% of the total, in fact.

The 2% difference between cultures is still statistically significant, though. After all, it's easy to distinguish Cuban music from gypsy music, from Indian music, and so on. I'd guess that some aspects of music must be more diagnostic than others to our ears. (I think that CantoCore only analyses songs, so out in the real world you can also throw in instrumentation as a means of recognition.)

What I want to know is if some cultures have more diverse music than others. That's true of genetic diversity, and it reflects our species' history.

So, just as Africans are most genetically diverse, and the rest of us are, give or take, a subset of them, is the same true of music? In Subsaharan Africa, cultural diversity mirrors biodiversity - that is, the places with the most species per square mile also have the highest density of different languages. So perhaps the same goes for tunes.

Do escaped transgenes persist in nature?

Of the things I get worked up over, genetically modified crops aren't that high up the list. (As an aside, I think the UK farm-scale trials of a few years back did a good job in showing that GM crops tended to reduce agricultural biodiversity, but that this was a result of the changes in farming methods associated ith them, rather than any property of the crop per se. Likewise, I think the issues around GM crops are more to do with big agribusiness controlling the food chain, loss of varietal diversity and so on, rather than that the technology is somehow immoral or that eating them is bad for you. It's striking that in places where they don't have the luxury of squeamishness about agriculture, such as India and China, GM is rather less of an issue.)

That said, I think this paper in Molecular Ecology by Suzanne Warwick et al is interesting. They show that herbicide resistance genes from oil-seed rape (Canola) have crossed into a weedy relative, Brassica rapa and set up home there (they've been there for 6 years, apparently).

"Most hybrids had the [herbicide resistance] trait, reduced male fertility, [and] intermediate genome structure", say Warwick et al. Whether they are more or less fit than the wild variety - and what consequences this has for the weediness of B. rapa - they don't say in the abstract. That's clearly something worth studying; I don't think panic is in order, but vigilance is, so well done to these researchers for playing the long game. Although by the time we find out we've created a super-weed it may be a bit late.

Batty like a FoxP2

Back in 2001, FoxP2 was the first gene to be linked to human language. The gene was hunted down by studying a British family with extreme difficulties in forming speech. I wrote about (paywall) this work at the time.

Since then, there's been a bunch of studies on the gene - revealing, for example, relatively large differences between the human sequences and that of other primates. But it was thought that, humans aside, there was relatively little variation in vertebrates.

Well, just goes to show how taxonomically restricted our genetic knowledge is, because a Sino-Anglo team has just discovered that the gene varies lots in bats, which don't talk, but do echolocate. There's a news report about their PLoS One paper here.

To see how the variation between closely related bat species really does dwarf that seen between much more distantly related beasts, check out this figure.

Nice. But FoxP2 is not giving up all its secrets just yet. The pattern of evolution - what's been selected for what - is not clear from the sequences, there's just a lot of difference. And comparing bat sequences with other species doesn't help much

Evidence from birds, which likes bats and people show vocal learning, is shows 'no evidence of specific mutations associated with vocal learning abilities...if variation in FoxP2 has a role in vocal learning then it is not straightforward'. Nor are there clear similarities with whales, which also vocal learn and echolocate.

So what is FoxP2 uP2? If it's a 'language gene' it looks as if it's role isn't in what we think of as the clever stuff of language - grammar and syntax - but in the mechanics: the motor control needed to produce tightly controlled sounds, say. But, as far as I can tell, there's no hard and fast links between the gene sequence and this ability. It's just involved somewhere down the line.

One clue is that FoxP2 is a transcription factor - it's product controls the activity of other genes. Maybe this is why comparing species gives few clues as to how its sequence relates to its function: because it's an information processing gene and not making something like haemoglobin, the structure of which is jolly important, maybe its free to vary more, and to mean different things to different animals.

I don't know how much we know about the genes it regulates - I couldn't see anything in the paper, so I'm guessing not much.