EVOLUTION= Evolution is the sequence of gradual changes which take place in the primitive organism over millions of years in which new species are produced.
It is through the constant process of evolution taking place in the organism since the of life that such an enormous variety of plants and animals have come to exist on this earth at present.
SPECIATION= The formation of new species is called speciation.
New species are formed when the population of same species splits into two separate groups which then get isolated from each other geographically by the barriers such as mountains ranges, rivers or the sea. The geographical isolation of the two groups of population leads to thier reproductive isolation due to which no genes are exchanged between them.