what is speciation

http://www.biology-online.org/dictionary/Speciation

Speciation is the evolutionary process by which new biological species arise. It occurs when populations of a single species become isolated from each other for a long enough period of time that genetic differences accumulate, leading to the formation of distinct species that can no longer interbreed and produce fertile offspring.

To understand this concept further, let's break it down into steps:

1. Geographic isolation: This is the first step in the speciation process. It occurs when a population of a species becomes physically divided or separated, such as by a mountain range, a river, or the movement to a new habitat.

2. Genetic divergence: Over time, the isolated populations may experience different environmental pressures and natural selection, leading to different adaptations. Random genetic mutations can also occur independently in each population, introducing genetic variation.

3. Reproductive isolation: As genetic differences accumulate, individuals from different populations may become unable to produce fertile offspring if they were to come into contact again. This is often due to genetic incompatibilities and differences in reproductive structures, behaviors, or timing.

4. Formation of distinct species: Once reproductive isolation is established, the populations are considered separate species. They will continue to evolve independently, further diverging genetically and adapting to their respective environments.

It's important to note that speciation is a gradual process that can occur over long periods of time, and there are different mechanisms that can drive it, such as allopatric speciation (geographic isolation), sympatric speciation (without geographic isolation), and parapatric speciation (partial geographic isolation). By studying the genetic and morphological differences between populations, scientists can determine whether speciation has occurred.