Journal Entry: 28/4/17
Organisms need to mate and produce offsprings that are fertile and can produce more offsprings themselves. In the theory of evolution, we know that new species can be produced. For a new species that is healthy and fertile to be produced, they need to overcome certain drawbacks. These drawbacks can be categorized into two different types: prezygotic and postzygotic. In prezygotic, organisms cannot mate at all because of factors such as different mating times, different habitats, different courtship rituals, different bodily structures, and the inability of sperms to fertilise the eggs. As for postzygotic, organisms can mate, however the offpspring that they have produce is infertile, therefore they cannot produce offspring of that hybrid. Speciation can occur in two different ways: allopatric and sympatric, the latter being much more rare than the other. In allopatric speciation, one species become geographically isolated and become no longer uniform as they evolve into different species. in sympatric speciation, they are not geographically separated however there is a rapid genetic change.