[From many - one.]

Depends.

In a generally benign environment, there'll be lots of variation among the critters.

If the environment tightens up, many of the variants will be killed off.

Benign menas benign for the critter (which includes plants, bacteria etc).

[Elsie]

In a generally benign environment, there'll be lots of variation among the critters.

Why?

I've heard that the changes in environment 'force' changes in the critters.

If not, then there would be lots of 'variation' in all KINDS of critters: humans included.

Noticed any wierd ones among us lately?

;^)

(Other than the check-out tabliods, that is....)