The Fossil Record, Speciation, and Mutation Rates

[Joao]

@johnZ

Joao:
…Without NEW mutations, there is plenty of variation.

You’ve missed the point.

I’m responding directly to the claim YOU made, which is that mutation rate is limiting:

@johnZ

the earlier appearance of a species (transition from ancestor) presumably means a shorter time for mutations to occur that allow for the the new species to be selected.

To know that, you’d have to know the ratio of the amount of polymorphism caused by new mutations per generation to the amount of existing polymorphism. Both of these are frequently and objectively measured parameters. No theory, no belief, just raw data.

But you clearly don’t know.

Joao:
if God reduced the mutation rate in humans to zero today, how many generations would it take to reduce polymorphism in the population by 50%?

Again missed the point.

It’s precisely the point if you claim that mutation rate limits speciation.

[Chris_Falter]

@dcscccc

joao. how many mutations you think we need to a 100 amino acid functional protein?

@dcscccc - I have no idea what this question means. I do find the evolution of protein domains to be an interesting topic, so I’m wondering if you might rephrase the question so we can work constructively on the topic.

[johnZ]

I suspect that this question relates to the number of possible permutations or combinations of individual components or base pairs that could possibly form in the random process to get one functional protein with 100 amino acids in it.

[dcscccc]

yep. a protein need a minimum part to its function. take this paper for example:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC211289/

a minimal flaglellin protein need at least 310 aa to nimimal function. its a lot of aa.