In <10848 at raven.ukc.ac.uk> mjg5 at ukc.ac.uk (ShereKhan) writes:
>>Ok. From all the follow-ups there have been I now feel that evolution is
>indeed a process that is still going on. But I also agree with the person
>(cant remember name) who says that chaos `theory` may well have some effect
>on the process. Arent random genetic mutations a large cause of evolutionary
>change....causing some beneficial or even detrimental changes on the phenotype
>of the organism?
>Evolution may still be carrying on but will the human morph change in a dramatic
>way as a result of this in the future? I personally feel that the actual morph
>of humans is perfect for it`s surroundings. Biochemical improvements may result
>through evolution in humans but thats all (isnt it?)
>>marc
>>
The question is to differentiate 'mutants' from 'variants'.
By definition a mutant is a new species & is believed to not yield fecund offspring
when crossed with 'stem' species. A variant is a individual or group of organisms that
may show genotypic, and possibly phenotypic differences.
The 'variant' may evolve into a spp if the trait is able to dominate (thus the need for
isolation of the population) via individuals who become hmozygous to the trait. In addition
the trait must bestow some advantage (nat selec).
Time is the other major factor. Organisms that have slow maturation times will evolve
slower. THus the time frame has to be extended for ascertaining if evolution is
happening.
The chaos or random aspect of it that the mutation is a random process, and the probability of offspring carrying
the mutant gene is another p, thus at the first order we are dealing with the product of
2 very small p's, which will make the p of an offspring carrying the mutation reaching reproductive age
orders of magnitude smaller.
THus concluding that evolution has stopped in the case of human (genetic evolution) requires better
attention to the factors & how to quantify them.
Randomness yes, the 'taking' of the random process to result in a new spp. Maybe our time
frame is to short.
Bacteria are nice, as their time frame allows us to see all sorts of mutants & variants.
They do have the advantage (from the standpoint of evol only) of x by cell div.
Esat Atikkan
