In Sex Evolution
We all know the world is finite. The non-renewable resources such as food, energy and fresh water have bear witness that our world naturally constructs a finite sphere. The world was constructed by the accumulation of biological process, involving environment changes and selection, as we may call it evolution. At practical level, individual tend to subsist their life in order to adapt due to mass utilization of finite resources and environment changes. We have to adapt, and try to survive.Is it true? Should we be afraid of this limitation?
According to Darwin and Wallace, ﬁniteness of resources however triggered the competition and natural selection make thepopulation stays on a constant yet considerable number. We live in the world where we try to adapt and to survive; from the finiteness of resources. Rooting from the game theory, which mainly focuses on cooperation (and conﬂict) between two individuals, it is clear that we make strategies to survive. One of them is sex and recombination.
Back on the middle and late 20th century, the research on reproduction strategy has shown that sex and genetic recombination double the chance of successive adaptation for the offspring, compare to the mutation of those whom produced asexually. That’s because sex and recombination generate new variation of alleles.Cynically saying, successful adaptation costs a lot; one has to do sex and recombination.
In an infinite population with mutation, all possible combinations of alleles (variants of a particular gene) are always available. It is why they could produce the offspring at any given time, without sex. But, somehow we have to accept this is not enough to prove that they could adapt well in environment changes. This is caused by the genetic drift. Paradoxically speaking, genetic drift; changes of alleles presence as a result of genetic composition and random events rather than by natural selection – of infinite population is inadequate. Meanwhile in a finite population, the drift is moderately adequate and adaptive.
Models that consider modifiers in finite populations have shown that drift tends to contribute to the evolution of sex and recombination.And this drift theory in sex and recombination showed that all populations are finite.