speciation

Speciation is the process by which one species splits into two or more separate species.

• Variation • Isolation • Selection.

Most genetic mutations have no effect. A few, however, produce new alleles, which result in new traits. These new traits make the population more diverse. This is called variation.

Isolation happens when different groups within a population are somehow prevented from interbreeding. There are two main ways in which this occurs: Geographical barriers: oceans, rivers, mountain ranges and gorges Climatic barriers: rainfall, temperature, sunlight and ocean currents

the three types of baobab trees (australian, african and the giant baobab) the squirrels of the grand canyon

Each group is exposed to selection pressures, such as: Food / shelter availability Environmental conditions Biological factors (predators, diseases etc.) Since these pressures are different for each group, different traits are advantageous. Over time, the groups become less and less alike. Eventually, the two groups become so different that they cannot mate any more (or if they can, their offspring are infertile). When this point is reached, the two are considered different species.