quote:
Originally posted by John Paul:
Rationalist:
And what about all of the other ambient mutations in the genome. Are we to believe that of all of the mutations that are introduced into the gene pool of a species, only one at a time can become fixed?
John Paul:
A mutation, any mutation, has a better chance of getting lost in a population than it does becoming fixed. As we know most mutations are either harmful or neutral, why would these mutations even be selected? Beneficial is a relative word as there is no way to predict what would be selected for at any point in time. What may be beneficial for one generation may not be beneficial for future generations. However I am open to any evidence that shows that more than 1 beneficial mutation can become fixed in a population in a shorter timeframe. Also becoming fixed might not even be enough. What happens when an organism with this new mutation mates with an organism without it?
And yes the 1667 is derived using Haldane's dilemma. If you think it is faulty perhaps you should start a thread to explain why you think it is.
Thank you so much for your reply! Let me see if I have this correct. Please correct any errors. 1667 refers to beneficial alleles in the human line over the course of 10 million years. 225,000 refers to the coding difference between humans and the human-chimp ancestor. Is the relationship between the 1667 alleles and the number of coding differences known? I would assume that the majority of 1667 would be single base pair substitutions, but a transposon or two would allow many base pair differences. Does the 225,000 coding difference include neutral and harmful mutations?
Let me ask a hypothetical question. Assuming common ancestry for humans and chimps, how many beneficial alleles do you estimate it would take to create a modern human from this common ancestor? That seems to be a key question, but I am not sure how to answer it.
You also asked "What happens when an organism with this new mutation mates with an organism without it?"
I think the answer to this is that 50% of the offspring would receive the beneficial mutation. If it enabled them to survive better, it should in theory enable the offspring to more effectively compete for resources and have more offspring, and should allow the mutation to accumulate in the population.
One other thing. You said "This method is akin to Dawkins' "weasel" program, which he admits isn't indicative of reality."
It is important to note that Dawkins is merely demonstrating the concept of natural selection as opposed to blind chance. I have his book, and he is quite clear on this. This is related to your question above about mutations. Dawkins just showed that if selection is operating, selected mutations would accumulate.
Looking forward to your reply.
As-sallamu aleykum! (I was told that you are a fellow Muslim!)
FK
[This message has been edited by Fedmahn Kassad, 08-18-2002]