Abzhanov started by trying to pinpoint the gene changes that led to the myriad beak shapes of Galapagos finches. In 2004, he showed that all the finches share a handful of genes crucial to beak development, but instructions for the signalling molecules they control vary from bird to bird. Abzhanov realised that a similar process might underlie the much bigger evolutionary shift from snouts to beaks.

    The tip of an alligator snout is made of a separate set of paired bones called the premaxillary, but in birds, these have fused with the main of the upper jaw to form a single, sharp bone.

    Abzhanov scanned signalling molecules in alligator and chick embryos and found that two of them -- known as sonic hedgehog and fibroblast growth factor 8 -- show up before the snout and beak form. In gators, however, the molecules were only present along the sides of the face. Chicks express them both at the sides and centre of the developing face. What would happen, he wondered, if he turned that central expression off?

    He developed a gel bead full of proteins that stick to the signalling molecules and deactivate them. As the molecules arrived at the centre of the embryonic chick face -- around day 5 -- Abzhanov added his bead to the mix. Sure enough, the chicks developed paired bones. "It looks exactly like a snout looks in an alligator [at this stage]," says Abzhanov.

You think chickens came from alligators?

Is this an observation or an interpretation?

Verge wrote on Aug 22^nd, 2011 at 8:52am:

A few scientists have been experimenting with reactivating 'unused' dna in chicken embryos. It was done to see if birds really are linked to dinosaurs and seems to work.......One researcher even manage to turn on the genes for long tails (like T-rex and Raptors) and for the carnivore style teeth (or tooth buds) in chicken embryos..

freediver wrote on Aug 22^nd, 2011 at 7:16am:



No, chickens, along with all birds came from the smaller Dromaeosauridae class of theropod dinosaurs, where as alligators are members of the Crocodilia class of reptiles...

gizmo_2655 wrote on Aug 22^nd, 2011 at 1:13pm:


Speaking of dinosaurs, Mr. Science, care to explain in 100 words or less how the Jurassic was so efffing hot, if CO2 doesn't cause warming?

Seriously, you are as bad if not worse than an evolution sceptic, the form of thinking you subscribe from is cut from the exact same cloth.

gizmo_2655 wrote on Aug 23^rd, 2011 at 9:52am:


CO2 isn't the only thing that warms or cools the earth. Changes in Earths orbit, changes in the Sun and changes in continental drift all affect global temperature.

But having said that, all things being equal, if we increase the concentration of CO2 in the atmosphere then we will increase the global temperature.

How do you explain the Carboniferous Period having the same temperature as the Jurassic, when the Co2 was between 4500ppm and 7000ppm, when the Co2 levels in the Jurassic had dropped to 1100ppm????