Question

what is spection ?how does it occurs

Answer 1

Hey mate..
========

☆What is Speciation ?☆

▪Speciation is basically a biological process by which new biological species arises.

☆How does Speciation occurs ?☆

▪Let's consider a pair of subspecies that are diverging in some physical or behavioral or other traits. Say, one subspecies is taller and exploits high branches, and one is shorter and exploits underbrush.

If two members of different subspecies interbreed, and their offspring is intermediate (which may not happen, of course, but this is simplified), then the offspring may be less fit than either pure subspecies, and would be competing with each less successfully.

Therefore, it would not be a good evolutionary strategy to interbreed with the different subspecies, and individuals who developed mechanisms to avoid such interbreeding would have more fitter offspring, who would also carry along these isolating mechanisms, and you're on the way to reproductive isolation, i.e. speciation. 


▪This may be one reason so many similar looking species have some distinctive call, or mating ritual, or whatever.  It keeps them from throwing away their genes in less competitive genomes. 

▪Now, A question arises :-- How did humans develop reproductive isolation?  We don't know, now, because our closest relatives are extinct - Neandertals and Denisovians. We do know we could interbreed with them, because we carry some of their genes even today.  But because they were genetically distinct, we didn't interbreed wildly, even though they were clearly very human in appearance. 

▪My speculation is that this is the source of the "uncanny valley" - the revulsion we apparently feel when something is very human-like, but not quite human. Perhaps that's the remnants of the reproductive isolation that was part of our speciation events.

Hope it helps !!