When Darwin proposed his theory
of evolution by natural selection, he believed it helped explain the
origin of the many species found on earth. For a new species to
form, the passage of genes between two groups of organisms must be
Once each gene pool is
isolated, natural selection can act on each population
independently. If the populations encounter different conditions,
they may evolve in different ways.
In this activity, we'll look at
the types of barriers that can divide a population into separate
species. We'll introduce the different ways a new species can
evolve. We'll see what happens if two related species come into
contact and breed with each other. Then, we'll look at the rate at
which new species develop.