Thread:BastionMonk/@comment-3213993-20151022005817

Here is something I have pondered. Horner says that the biggest hurdle to a chickenosaurus is getting a long tail to develop. This is true if you want to create a chickenosaurus by modifying embryonic development non-genetically, but when it comes to creating one genetically, I think the biggest hurdle is the teeth. Talpid2 makes tooth buds develop in chicken embryos, but it has pleiotropic effects that kill it before it hatches.

Now, I have concluded that while talpid2 confers an ancestral phenotype (teeth), the affected gene (C2CD3) is probably not the ancestral gene that turns on tooth development in toothed animals because the gene is pleiotropic and the talpid2 mutation is in the coding region. That still doesn't explain why talpid2 "teeth" have the same gene expression as "real" teeth though. What do you think? 