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From: "Diana Gale Matthiesen" <>
Subject: Re: [DNA] GENEALOGY-DNA T-Rex
Date: Mon, 16 Apr 2007 15:56:14 -0400
References: <bc0.101156c3.33550da9@aol.com>
In-Reply-To: <bc0.101156c3.33550da9@aol.com>


Sorry to be a wet blanket, but...

There is no doubt (and never has been amongst zoologists or paleontologists)
that birds and reptiles, including dinosaurs, have a common ancestry (or that
mammals and reptiles have a common ancestry, too). But the earliest birds
appeared in the late Jurassic, over 100 million years before the dinosaurs of
the late Cretaceous, like T. rex.

It boils down to a semantic quibble over what does or does not constitute a
"dinosaur," but I think it's unfortunate that journalists (and even some
paleontologists), don't mind equivocating when they can sensationalize their
statements by saying birds evolved from "dinosaurs" [using a technical
definition applied to an early ancestral group], when clearly no bird evolved
from T. rex or any other "dinosaur" [using the popular definition of dinosaur,
which applies to the spectacular late Cretaceous ones].

I haven't read the Science articles, but I don't need to read them to be able to
assume what they've proven is that chickens and T. rex have a common ancestor,
which is not exactly an astounding revelation. What is astounding is that they
can find any DNA, at all, in a fossil that old.

Diana

P.S. Bone itself is about 50% mineral and 50% collagen, in addition to the
cartilage and connective tissues adhearing to its surface. [Culinary aside:
when making homemade soup, it's the amount of collagen in it that makes the
difference between a soup that is "rich and hearty" and one that is "thin and
watery," which is why bones are the main ingredient in a good soup stock.]

> -----Original Message-----
> From: On Behalf Of
> Sent: Monday, April 16, 2007 1:35 PM
> To:
> Subject: Re: [DNA] GENEALOGY-DNA T-Rex
>
> And a comparison of the protein's chemical structure to a slew of other
> species showed an evolutionary link between T. rex and chickens, bolstering
the
> idea that birds evolved from dinosaurs.
>
> The collagen proteins were found hidden inside the leg bone of the T. rex
> fossil, according to two studies published in the April 13 issue of the
journal
> Science. Collagen is the main ingredient of connective tissue in animals and
> is found in cartilage, ligaments, tendons, hooves, bones and teeth. It
> yields gelatin and glue when boiled in water.
>
>
> If they can extract DNA from some bone this old, perhaps there are
> applications for extraction of more recently deceased specimens?
>
>

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