Tag: Current Biology

Remarkable dancing birds: a cure for Parkinson’s?

April 30, 2009 • 12:13 pm

In his various works, Darwin always thought that the roots of many human behaviors and emotions lay in our relatives.  So, for example, the rudiments of human morality could be seen in the social behaviors of our primate relatives.  But until now nobody has seen any animal with behavior indicating a predisposition to produce or respond to music.  Until now.  The newest issue of Current Biology has an article on two species in which individuals are able to move to a musical beat.  This behavior appears unique in the animal kingdom.  One bird is a sulfur-crested cockatoo,  “Snowball” (seen below), who really shakes a leg, and the other is Alex, an African grey parrot who moves his head to a beat. You can also see videos of both behaviors on the BBC Science page that reports on this phenomenon.

the authors conclude:

The discovery of synchronization to music in a nonhuman animal shows that a fundamental aspect of music cognition is shared with other species and provides valuable clues about the neurological substrates of this aspect of music. The finding also suggests the utility of developing animal models of movement to music. Such models could have relevance to the study of human movement disorders (including Parkinson’s disease), symptoms of which have been shown to be alleviated by moving with a musical beat.  More generally, it appears that comparative studies of other species can be a powerful approach for gaining insight into the neurobiological and evolutionary foundations of our own musical abilities.

Title, authors, and summary below.   Thanks to Matthew Cobb for calling this to my attention.

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Experimental Evidence for Synchronization to a Musical Beat in a Nonhuman Animal

Aniruddh D. Patel1,,,John R. Iversen1,Micah R. Bregman1,2andIrena Schulz3

1 The Neurosciences Institute, 10640 John Jay Hopkins Drive, San Diego, CA 92121, USA
2 Department of Cognitive Science, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
3 Bird Lovers Only Rescue Service, P.O. Box 552, Dyer, IN 46311, USA

The tendency to move in rhythmic synchrony with a musical beat (e.g., via head bobbing, foot tapping, or dance) is a human universal [1] yet is not commonly observed in other species [2]. Does this ability reflect a brain specialization for music cognition, or does it build on neural circuitry that ordinarily serves other functions? According to the vocal learning and rhythmic synchronization hypothesis [3], entrainment to a musical beat relies on the neural circuitry for complex vocal learning, an ability that requires a tight link between auditory and motor circuits in the brain [4,5]. This hypothesis predicts that only vocal learning species (such as humans and some birds, cetaceans, and pinnipeds, but not nonhuman primates) are capable of synchronizing movements to a musical beat. Here we report experimental evidence for synchronization to a beat in a sulphur-crested cockatoo (Cacatua galerita eleonora). By manipulating the tempo of a musical excerpt across a wide range, we show that the animal spontaneously adjusts the tempo of its rhythmic movements to stay synchronized with the beat. These findings indicate that synchronization to a musical beat is not uniquely human and suggest that animal models can provide insights into the neurobiology and evolution of human music [6].


Summary

WEIT reviewed in Current Biology

March 24, 2009 • 10:48 am

I must be on a roll — another review of WEIT, and a good one, by Tom Tregenza in the latest issue of Current Biology.   Tregenza works at the University of Exeter, where he (like me) studies speciation, as well as sexual selection and mimicry in cephalopods.

From his review:

Like many biologists, I occasionally panic that if the appeal of religious dogma can prevail over such a well-supported and rigorously tested theory as Darwin’s, then it can only be a matter of weeks before we’re all wearing sandals and the next breakthrough in oncology is expected to come from making offerings to a parsnip with a resemblance to the Virgin Mary. At such times, I vow that I will drag myself out of my ivory tower and try to explain what I do to the (surely fairly rational?) man in the street. Similarly, reading the manifestos of those seeking election to offices of the European and American Evolution Societies, there is universal agreement that evolutionary biologists need to do more to explain their work to the public. The fact is, however, that we’re still not very good at delivering on these good intentions. So, it is terrific to see a biologist of Jerry Coyne’s standing writing a book with the specific aim of explaining to any reasonably bright reader just why the theory of evolution is no more in doubt than the theory that tides are caused by the moon.

Coyne acknowledges the existence of religious accounts of biology, but by and large, doesn’t get sucked into addressing the arguments put forward by the religious proponents of intelligent design. This allows the book to stand as a scholarly, yet delightfully readable account of the state of the art, avoiding the tedious and fatuous debates beloved of the proponents of ‘intelligent design’. . . .

If I was being picky, I might comment that his explanation of the difference between selection favouring traits that act for the good of a gene (ubiquitous), or for the good of the species as a whole (very rare) might have warranted more than a couple of pages (since this is a distinction that is frequently misunderstood). But in general, this is a book that is a pleasure to read, and that even professional biologists will find energising and exciting. The fact that Darwin’s theory makes so many predictions, none of which has ever been falsified, and the prospect of the mountain of supporting evidence becoming ever higher, makes it easy to make a further prediction: it is only a matter of time before the religious proponents of intelligent design make it a fundamental tenet of their ideology that the pattern of life has been made that way specifically to fool biologists. In which case, evolutionists can take comfort in knowing that the creator specifically had them in mind at every step of the process.

On re-reading The Origin

February 13, 2009 • 6:44 am

The journal Current Biology asked a group of us to re-read Darwin’s great book and write a few paragraphs of response; the collection, which is quite intriguing, is here. Besides my take (which is, as I’ve already mentioned, a defense of the term “Darwinism”), there are pieces by Bob May, Matt Ridley, Peter Lawrence, Matthew Cobb, Christine Nüsslein-Volhard, Mark Ptashne, Simon Conway Morris, Marlene Zuk, Andrew Berry, and Hopi Hoekstra.

It’s particularly interesting to contrast the ending of Matthew Cobb’s piece (he is an evolutionary biologist at Manchester) with that of Conway Morris’s (he is a paleontologist at Cambridge). Conway Morris, who is of course religious, contends that the human mind is not explainable by evolution, while Cobb thinks that our minds are on an evolutionary continnum with those of animals. (This of course parallels a famous disagreement between Darwin and Wallace, who had the views of Cobb and Conway Morris respectively).

Conway Morris of course wrote Life’s Solution: Inevitable Humans in a Lonely Universe, a very large book which, by presenting hundreds of pages of examples of evolutionary convergence (a worthwhile task, with lots of good stuff), argued that the evolution of humans was inevitable. I have argued against this view, asserting that our complex intelligence arose only once, and so is neither an example of evolutionary convergence nor inevitable.