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Re: Rconstructing DNA (was Re: Dino-fuzz found in amber?)



Roberto Takata <rmtakata@gmail.com> wrote:

> You simply cut the part of the email message in which I actually
> showed how to make comparisons. So I will reproduce it:
> "That comparison allow us to have some improved knowledge about T-rex's
> DNA sequence. For example, the second codon first position in T-rex
> most probably was a C too (and not a T). Of course we cannot rule out
> the possibility of point mutation (either from T to C in chicken or C
> toT in T-rex).
>
> The sixth codon is more dramatic. The S aa could be coded by a TCN
> codon or by a AGY codon. In the chicken it is AGC codon. It would take
> at least two point mutations to convert a TCN into AGY and vice-versa.
> So, most probably T-rex had a AGY codon in that position."


Including your reasoning doesn't help your cause; your assertion is
still incorrect.  It would take too long to explain why.  But one
starting point is the assumption that the "T. rex" sequence is more
likely to adhere to whatever the chicken (or zebra finch) has, despite
the the bird and tyrannosaur lineages having diverged some time in the
Jurassic.  Why do you assume that the choice of base in the chicken is
ancestral?


> http://www.ncbi.nlm.nih.gov/protein/P0C2W4.1


OK, that sequence is indeed assigned to _T. rex_.  The "_T. rex_"
peptide sequence just happens to show 100% match to the chicken
peptide sequence....





Cheers

Tim