Critics have long believed that evolutionary biology, the science said it more profound, at best, that is, "think", but the fact is just the opposite. Recently, a group of evolutionary biologists to determine when a large number of unexplained phenomena before how to participate in the process of human evolution, from the anatomy, physiology, embryology and behavior, etc. Of course, not all problems have been solved, for now, there are still many unexplained phenomena, one of the most prominent is the origins of bisexual.
This question sounds simple, but it was befuddled by the world's most prominent among the field of the mind. For any feature, to participate in is a necessary factor in the process of evolution and breeding process, said that in more detail is successfully make related genes to the next generation. So, if bisexual women and men is a product of evolution, and it really is. The genetic factors associated with same-sex attraction will get from people on gay preference reproductive benefits of some kind. So the problem is very obvious, is impossible to reproduce the same sex, so why not natural selection "erase" same-sex love from evolution? For the entire human race, a bit trivial changes can cause potential evolution process.