| Assuming evolution does exist, then populations, which are in their own niches, would adapt to better survive in them. Niches, by the way, are the combinations of an organism's environment and its occupation in the environment; for instance, the niche of freshwater fish may be a lake and may be to eat smaller fish and kelp. If organisms do not adapt, then they may perish due to ecological effects. There was an incident in England with black and white moths that alternatively dropped in population due to industrialization and pollution that either helped or hindered their respective camouflages on trees that may have been colored with soot. So, if a major geological disaster or change, for example, occurred on Earth, then either all species would be wiped out, or some populations of species would adapt to the changes and in turn create a new species. Their genetic change, which makes them adapt to the environmental disaster, is brought about by their natural selection. The entire theory of evolution relies on natural selection bringing about morphological and physiological changes that result in a progressive macroevolution. One could only say that relatively tiny, anaerobic heterotrophs evolved into comparatively complex humans if he or she supported this ideal.
P.S.: I do not support evolution, though, since I support Catholic, creationist beliefs and I do not see the possibility of macroevolution and natural selection occurring over a certain time frame and against so many odds. |