BIRD`S   EVOLUTION           

The genomes of 48 species of birds reveal the biological Big Bang after the extinction of the dinosaurs

The mass of information is matched only by the web of government transparency, but hopefully better understood. After four years of work coordinated a team of 200 scientists from 80 institutions in 20 countries has sequenced (read) the genomes of 48 species of birds, leaving the innermost secrets of the evolution of birds in view of anyone who can watch . The results are presented in technical articles 29, eight in   Science, and clarify almost all enigmas surrounding the 10,000 species descended from dinosaurs of the Cretaceous now hovering overhead.

What is the common ancestor of birds, crocodiles and dinosaurs? Is the exuberance and diversity of the result of an endless trial period birds and error that occurred before the fury of the Earth swept the great reptiles of his presence? Or rather a Big Bang evolutionary came just to fill the void left by the extinction of those beasts? What has in common vocal learning in birds and humans? For that matter, why birds lost teeth?

Avian Filogenómico The Consortium is led by Guojie Zhang, the National Gene Bank of China, Erich Jarvis, Duke University, and Thomas Gilbert, the Natural History Museum of Denmark. It has received important contributions Toni Gabaldon group, the Center for Genomic Regulation (CRG) in Barcelona and the University Pompeu Fabra. The complete list of the 29 items in   Science,   Genome Biology,   GigaScience   and other scientific journals   Duck, ostrich, emu, crow, ibis, falcon, eagle, woodpecker and so 48 species of birds have not been chosen for its availability or for their economic value -there hen takes the cake, and it was sequenced in decade bridge- but represent all major evolutionary branches of the 10,000 species of birds. This is the "major genomic study of a single class of vertebrates to date," said Zhang notes. "Just a sampling of this scale," says Gilbert, "you can begin to explore the true genomic diversity of an entire class of vertebrates".

There have been previous attempts to clarify the evolutionary tree of birds comparing twenty genes among some lineages and others, but the results were difficult to interpret, or directly contradictory. "Not that 20 genes are few," says Toni Gabaldon from Barcelona, ​​"is that genes were not sufficient to solve the problem."

It is the largest genomic study of a single class of vertebrates that has been done to date

A gene is a DNA segment (gattacca ...) containing the information to produce a protein ("encodes" a protein, in the jargon). And these "code sequences" have a false story about the evolution of birds. The reason is that extensive experience convergences: two different species 'find' the same code sequences when they have similar lifestyles. Seem relatives, neighbors when they are alone with similar needs. "Only the non-coding genome gives us the true evolutionary clock" concludes Gabaldon.

With high-resolution genomic magnifier, it is now clear that what we call "waterfowl" are not a homogenous group, but three lineages that evolved independently: another case of evolutionary convergence. Now is also seen that the common ancestor of songbirds, parrots, woodpeckers, owls, eagles and hawks was a predator, the kind of beast that sits on top of their food chain, and theirs are the lion, Nile crocodile and tiger sharks. The beautiful singing of birds is a product of "nature red in tooth and claw" Tennyson said.

Duck, ostrich, emu, crow, ibis, falcon, eagle, woodpecker and so 48 species of birds have been chosen to represent all the major evolutionary branches of the 10,000 species of birds

All this diversification and all   Neoaves, which actually accounts for 95% of the current avian variety, have been dated to the time of the aftermath of the extinction that ended the Cretaceous 66 million years ago, and that not only swept the dinosaurs except the avian dinosaurs and flying descendants who are under present birds, but also most of all animal species existing at the time.

The genomes show that the evolutionary diversification of birds occurred in a biological Big Bang no more than 10 million years after the extinction. And not for a long process full Cretaceous, as claimed other very recent rival theories.

Finally: do you have anything in common vocal bird and human learning? Certainly yes. Not that share a common evolutionary origin, but because, once again, the two brains found similar solutions to similar problems. Encode the world as a sequence of sounds, process and produce them in imitation of the bird in front of you seems to be a very specific problem that only supports one type of solution, at least in this valley of tears. Any day see a crocodile singing: but do not trust what he says.

JAVIER SAMPEDRO   ELPAÍS