They need to cope with changing seasons and be able to withstand cold winters and hot summers
They start as single cell orginisms then they evolve from there.
hope that helps
<span>All of the following patterns were witnessed by Darwin except that species vary within very short spans of time. Charles Darwin put forth a coherent theory of evolution and amassed a great body of evidence in support of this theory. By the 19th Century, a number of natural historians were beginning to think of evolutionary change as an explanation for patterns observed in nature.</span>
homologous chromosomes ... sister chromatids
