Species and the theory of evolution

[ApostateAbe]

You may have thought that the definition of species was clear: a population where each sexual pair can reproduce fertile offspring. But, it turns out it is NOT cut and dry, nor would it be following from the theory of evolution. Speciation (the emergence of a new species) is a spectral process, and there is no single point in time where two populations are clearly two different species jumping out of only one species. As the two populations drift apart, then SOME of the potential interracial breeding pairs may produce fertile offspring, the remainder will not, and there will be fewer potential interracial breeding pairs as divergence progresses. Here is a tutorial about speciation from UC Berkeley:

Understanding Evolution: Speciation

 

[J842P]

That definition doesn't even cover the majority of life on Earth!

 

[ApostateAbe]

That definition doesn't even cover the majority of life on Earth!

You mean like because of ants and bees?

 

[Jokodo]

That definition doesn't even cover the majority of life on Earth!

You mean like because of ants and bees?

Because of bacteria, more likely.

 

[ApostateAbe]

You mean like because of ants and bees?

Because of bacteria, more likely.

Yes, good point. Among asexual reproducers, I expect the definition of "species" would blend in even more continuously with subspecies or races.

 

[J842P]

Yes, because of microbial life which is the dominant form of life in the biosphere.

Metazoans are basically this strange aberrations.