Sexual reproduction produces far more genetic variation than asexual reproduction. I’m asexual reproduction, only one organism is needed. In this process they copy their own DNA and create an exact copy of themselves. So, if you think about it, all the offspring ever created by that one organism is going to have the same genetics as it. They’re all going to be identical. There is no variation, or differences, between any of the offspring and the original organism. Bacteria reproduces this way, although through binary fission, they can sort of reproduce sexually. Sexual reproduction results in genetic variation. Two organisms are needed to create offspring. An egg cell and a sperm cell are needed from a female and male organism to create the new organism. Since two organisms are required, their offspring will be a mix of their DNA. This will create variation between offspring. Every new organism will have different genetics. This is why more advanced organisms like plants and animals have different DNA even if they are the same species.
A keystone species helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether.
