Geoscience Reference
In-Depth Information
DNA molecules break apart so easily, the best that could be hoped for
in separating dinosaur DNA from the insects is to find two or three
hundred letters of the genetic code still stuck together. This would
constitute an ordered sequence representing less than a millionth of
the whole genetic code—not nearly enough to make any sense of the
whole topic. So finding a piece of extinct dinosaur DNA inside the
body of an insect preserved in amber would be like finding a sentence
from a long topic that had been cut up into millions of pieces. With
just that one sentence, we would have almost no chance of under-
standing the meaning of the topic, because we would be missing
millions of other sentences, thousands of other paragraphs, and
dozens of other chapters. The scientists in
Jurassic Park
avoid this
problem by adding DNA from living animals to the dinosaur DNA.
However, we do not know
nearly
enough about how DNA works to be
able to patch pieces of living and extinct DNA together like this.
Since each kind of animal has its own genetic code, the result would
almost certainly be gibberish, not a sensible topic specifying how to
resurrect an extinct animal.
But let's make believe that we were somehow able to get all the
pieces of the genetic code for an extinct dinosaur out of the fossilized
insect in amber. Could we re-create the dinosaur then? Again, the
problem would be one of putting the letters, sentences, and chapters
back together in the correct order to make a sensible topic. Thus,
even if we had all the sentences (all the short segments of DNA in the
genetic code), our challenge would be similar to putting a huge puz-
zle back together when all of the pieces are similarly shaped. It would
be virtually impossible to put them all back together in the correct
order. But even if all the DNA segments could be assembled in the
proper order, the genetic code is only one aspect of what is needed to
re-create an extinct dinosaur or any other living animal. The mother's
body provides a whole chemical and physical environment that is
needed for the embryo to develop within before birth. The scientists
who cloned Dolly the sheep, for example, used the body of a living
female sheep to nourish the developing embryo. But we have no
mother's egg within which an extinct dinosaur embryo can develop.
Thus, we are missing an essential component in the process. Without
the supporting environment inside the egg, we would end up with
just a bunch of chemicals floating around in a test tube.
