Thank you Chris for a very imformative and interesting post. I did not know
about the "crossover reaction". That gives me something to chew on.
Here's a question: does a nucleotide pair switching places within a chromosome
pair constitue a "degrading" of genetic information in your mind? Or does
this allow for a Vast number of genetic makeups with no loss in "quality"?
Were Adam and Eve's genes the one perfect arrangement, or would these
crossovers lead to arrangements equally acceptable.
Followup: based on answer to the above, what is the difference between a
crossover and a random mutation? Are they fundamentally different kinds of
genetic alterations? Or is a crossover just a specific kind of mutation?
"Chris Ashcraft" <ashcraftC@...
> MIME Type:�multipart/alternative
> The characteristics common to any particular organism are altered
> primarily through reactions called crossovers. The gametes
> (sperm,egg,pollen) produced by organisms are genetically unique as a
> result of genetic recombination performed by the cells prior to
> fertilization. "Genetic recombination" is accomplished during the
> complex division processes called meiosis.
> During meiosis, the genetic pool of the cell winds itself into
> incomprehensibly dense structures called chromosomes which remain as
> equivalent units received from your two parents. Prior to dividing and
> passing this material to future children these homologous chromosomes
> react with one another during which genetic information is exchanged
> (crossing over). Following this, the homologues separate independent of
> one another so that the daughter cells are always unique.
> The existence of these reactions is common knowledge, and it is well
> understood that all offspring are genetically unique as a result. It is
> also well recognized that it is from a pool of variable offspring that
> nature selects, and it is through these selections that evolution
> occurs. Likewise we know all breeders are selecting from genetic
> recombinants; not mutants.
> When discussing evolution however, it would seem we must forget about
> genetic recombination, and breeding histories. They say the cell has not
> been designed with the mechanics to create genetic variability through
> controlled reactions; so copying errors and external mutagens are
> apparently responsible for offspring variability after all.
> They are blinded by their atheistic philosophy. The molecular machinery
> drives evolution, and the designer watches over us....
> Chris W. Ashcraft
> -----Original Message-----
> From: Lucy Stoner [mailto:big_brownzzz@...]
> Subject: Re: [CreationTalk] What's driving evolution?
> >Dumb newbie question. What is a "crossing over
> reaction"? Is there some text I can read that would
> explain this?