Sympatric speciation is a process of formation of new species by reproductive isolation alone. Two populations of same species present in the same habitat develop pre or post-zygotic strategies of reproductive isolation which in turn prevents interbreeding between them.
Since these two populations are present in the same habitat, there is no geographical or physical barrier between them to prevent gene flow. Reproductive isolation prevents gene flow between them. Gradually, these two populations evolve into two separate species.
Speciation is an evolutionary process in which new species arise. There are three types of speciation, namely; sympatric, parapatric and allopatric speciation.
<em><u>Sympatric speciation is a pattern in which speciation occurs in the absence of a physical barrier to gene flow; ex. polyploidy arising in flowers.</u></em>
In an Allopatric speciation on the other hand, a physical barrier arises and separates two populations, ending gene flow between them and allowing reproductive isolating mechanisms to evolve so that later if the two groups come back into contact they will no longer be able to reproduce together, therefore making them different species.
