C. Individuals moving into a population, gene flow can also be referred to as gene migration due to this
Answer:
The populations become adapted to different environments and eventually become so different that they cannot interbreed to produce fertile offspring.
Speciation is the evolution of one species into two different kinds, and when they become isolated, that is the final step, since they cannot interbreed any longer.
It form the contraction and relaxation of muscle
He could have it due to genetics from his parents or grandparents