How do species evolve from a common ancestor, even if they live in the same location? Sympatric speciation is an evolutionary process that drives this type of division between species that occupy the same habitat.
What Is Sympatric Speciation?
Imagine that your family has lived in one house for many years. In fact, it’s the only house your family has ever lived in. Now, imagine that your sister moves out of that house and into a house in a nearby neighborhood.
She begins her own family there and, through the years, her family continues to grow and live in this new house.When your family separated, you became different groups of people from the same common ancestor. Eventually, you might even evolve enough to feel that there are more differences between you than similarities. When this happens in nature, it’s called sympatric speciation. This process allows new species to evolve from a common ancestor, while the new and old species are still living in the same geographic region.
Sympatric Speciation Process
You might be wondering how one species can become two separate species, even though they still live in the same area. This can happen in a variety of ways, but let’s look at a hypothetical example to understand the process better.
We’ll start with a group of flies that are all the same species. There are two sources of food for them to choose from: red apples and green apples. At first, all of the flies feed on red apples, but at some point, some of the flies begin to prefer green apples.
Sympatric speciation occurs if interactions are so limited between these groups that mating no longer occurs between them. Each new population of flies will have genetic variation in its gene pool, which is the collective genetic information for the group. As they continue to mate with other members of their new group, these variations will become more prevalent in the population.
Over a long enough period of time, an entirely new species might develop.
Sympatric Speciation Examples
The hawthorn fly is an example of sympatric speciation based on a preference of egg-laying location. The ancestors of hawthorn flies used to lay their eggs exclusively on hawthorns but now lay their eggs on both hawthorns and apples. Both males and females prefer to mate and lay eggs on the fruit they came from, so there is little mating interaction between the two groups, and they have been separate long enough to have developed some genetic differences.Another example of sympatric speciation in animals has occurred with orca whales in the Pacific Ocean. There are two types of orcas that inhabit the same area, but they don’t interact or mate with each other. They also have very different behaviors and feeding habits, which is what is believed to have led to the divergence, or separation, of the original species.
Though not common, sympatric speciation is an important evolutionary process that can separate a species into two new ones. This is a relatively uncommon form of speciation, though it has been observed in hawthorn flies and orcas. The divergence of the two species will generally take place over a long period of time, and it can be the effect of differences in things such as diet, behavior and mate selection. Eventually, if mating no longer occurs between populations and there is a variation in their gene pool, sympatric speciation has occurred.
Your comprehension of this lesson could serve as encouragement to:
- Write the definition of sympatric speciation
- Discuss a hypothetical example of sympatric speciation
- Cite examples of this process in nature