[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Reverse-engineering the T. rex genome



> >  Sequence every single bird species genome, get
> the consensus
> >  sequences for each node on the tree, and
> determine the consensus
> >  sequence for the most basal node.
> 
> "Consensus sequence" and "ancestral sequence" are not the
> same thing. Phenetics and phylogenetics are not the same
> thing...


Simply put, *at best* (making some entirely overoptimistic assumptions on 
ecology and physiology having marginal influence on molecular evolution), the 
task would be as "easy" as determining an ostrich's genome sequence from that 
of all neognaths and *no* paleognaths at all. The distance in time is roughly 
the same between (give or take about 10%) the neornithean-tyrannosaurid 
ancestor split and _T. rex_, and the neognath-paleognath split and _S. camelus_.

In other words, the inferred mt sequence for example would essentially consist 
of a few ultraconserved positions and A LOT of noise. Noise you couldn't even 
try to resolve, because the branch you're trying figure out has no crown taxa 
at all.


Eike