Re: Speciies? you gotta be kidding.
[ QUOTE ]
Or are you saying that 'ring species' means something like "a group of lifeforms that are closely related and all(?) the intermediate forms are concurrent?
[/ QUOTE ]
That's pretty close to what I'm getting at.
[ QUOTE ]
I'm not following why the current or extinct status of the intermediates has any status on the relationship between two groups. We have group A and group B with all intermediates alive and we call it 'relationship R'. We sneak in one night and kill off all the intermediates ... why does R change?
[/ QUOTE ]
The difference with the existing intermediates is that it allows gene flow between the different groups. Once they are gone then the two groups are isolated and really begin diverging due to genetic drift, lack of stabilizing selection, etc. that gene flow reduces.
This is not a trivial point.
|