Re: Directed Panspermia and Common Descent

Switch89 wrote:
In "29 Evidences for MacroEvolution" the author states that,

"Similarly, before alternate codes were found, Francis Crick and
Leslie Orgel expressed surprise that minor variants of the code had
not been observed yet:

'It is a little surprising that organisms with somewhat different
codes do not coexist.' (Crick and Orgel 1973, p. 344)"

As you may know, Dr. Theobald claims that supporters of common descent
predicted a universal genetic code long before the data were in.

However, a non-universal genetic code may be compatible with common
descent. Suppose that the first living organism replicated using RNA.
This organism might divide into many evolutionary lineages, which
separately evolve a DNA code. Then common descent would be true though
the genetic code would not be universal.

In fact, I think Francis Crick himself may have realized this. This is
what he said in a paper on directed panspermia,

"Our second example is the genetic code. Several orthodox explanations
of the universality of the genetic code can be suggested, but none is
generally accepted to be completely convincing. It is a little
surprising that organisms with somewhat different codes do not
coexist. The universality of the code follows naturally from an
?infective? theory of the origins of life. Life on Earth would
represent a clone derived from a single extraterrestrial organism.
Even if many codes were represented at the primary site where life
began, only a single one might have operated in the organisms used to
infect the Earth."

This paper can be read here:
http://profiles.nlm.nih.gov/SC/B/C/C/P/_/scbccp.pdf

Note that in 1973 Crick states that no orthodox explanation of the
universality of the code is completely convincing. This would
presumably include his own "frozen accident" hypothesis.

He goes on to say that it is "a little surprising that organisms with
somewhat different codes do not coexist". What exactly did he mean by
this? "Somewhat Different" seems to only imply that he is surprised
minor variations have not been found in the code. Crick goes on:

"The universality of the code follows naturally from an ?infective?
theory of the origins of life. Life on Earth would represent a clone
derived from a single extraterrestrial organism."

Now why would directed panspermia imply a single genetic code when
life arising naturally does not predict a single, universal code?
Because if life originated naturally (on earth), it could have easily
originated many times. Or, after it originated, if it did not possess
some type of genetic code (such as the hypothetical RNA organism I
mentioned) then it could have split into several lineages each of
which separately evolve a genetic code.

So it would seem that common descent alone does not predict a
universal genetic code, unless the universal common ancestor had
already evolved a genetic code.

God didit


.

Relevant Pages

  • Re: Directed Panspermia and Common Descent
    ... 'It is a little surprising that organisms with somewhat different ... a non-universal genetic code may be compatible with common ... Suppose that the first living organism replicated using RNA. ... of the universality of the genetic code can be suggested, ...
    (talk.origins)
  • Directed Panspermia and Common Descent
    ... 'It is a little surprising that organisms with somewhat different ... a non-universal genetic code may be compatible with common ... Suppose that the first living organism replicated using RNA. ... of the universality of the genetic code can be suggested, ...
    (talk.origins)
  • Re: Directed Panspermia and Common Descent
    ... a non-universal genetic code may be compatible with common ... Suppose that the first living organism replicated using RNA. ... of the universality of the genetic code can be suggested, ... "infective" theory of the origins of life. ...
    (talk.origins)
  • Re: Directed Panspermia and Common Descent
    ... 'It is a little surprising that organisms with somewhat different ... a non-universal genetic code may be compatible with common ... of the universality of the genetic code can be suggested, ...
    (talk.origins)
  • Re: Directed Panspermia and Common Descent
    ... predicted a universal genetic code long before the data were in. ... Suppose that the first living organism replicated using RNA. ... of the universality of the genetic code can be suggested, ... "infective" theory of the origins of life. ...
    (talk.origins)