Darwin famously observed finches in the Galapagos Islands with different beak shapes. When resources are scarse, a certain beak shape may allow a bird to access a food source that others cannot. Over generations, this selection creates a variety of beak shapes, each specialized for a unique food source.

In the following simulations there are three food sources: plants, insects, and seeds. Birds with long, narrow beaks are able to reach insects burrowed into trees, but cannot crush seeds. Birds with short, strong beaks are able to crush seeds, but cannot reach insects. All birds are able to eat plants.

As traits are naturally selected and specialization occurs, the differences within a population may become so great that they can no longer interbreed or share genes and therefore cannot be considered the same species. In the next simulation, when traits diverge to either solid red or yellow (longest or shortest beaks), they are no longer considered the same species.

A physical barrier, such as a mountain range, often effects speciation rates because it can limit crossbreeding between diverging traits. There are three modes of speciation, each regarding the physical location of diverging populations.

Allopatric Speciation
Diverging populations are completely geographically isolated from one another.

Parapatric Speciation
Diverging populations are somewhat isolated from one another, but contact and inter-breeding may still occur.

Sympatric Speciation
Populations continuously occupy the same space while diverging.

The previous page was an example of sympatric speciation because all the birds occupied the same location. The following page will demonstrate allopatric and parapatric speciation.

Darwin famously observed finches in the Galapagos Islands with different beak shapes. When resources are scarse, a certain beak shape may allow a bird to access a food source that others cannot. Over generations, this selection creates a variety of beak shapes, each specialized for a unique food source.

In the following simulations there are three food sources: plants, insects, and seeds. Birds with long, narrow beaks are able to reach insects burrowed into trees, but cannot crush seeds. Birds with short, strong beaks are able to crush seeds, but cannot reach insects. All birds are able to eat plants.

As traits are naturally selected and specialization occurs, the differences within a population may become so great that they can no longer interbreed or share genes and therefore cannot be considered the same species. In the next simulation, when traits diverge to either solid red or yellow (longest or shortest beaks), they are no longer considered the same species.

A physical barrier, such as a mountain range, often effects speciation rates because it can limit crossbreeding between diverging traits. There are three modes of speciation, each regarding the physical location of diverging populations.

Allopatric Speciation
Diverging populations are completely geographically isolated from one another.

Parapatric Speciation
Diverging populations are somewhat isolated from one another, but contact and inter-breeding may still occur.

Sympatric Speciation
Populations continuously occupy the same space while diverging.

The previous page was an example of sympatric speciation because all the birds occupied the same location. The following page will demonstrate allopatric and parapatric speciation.

Darwin famously observed finches in the Galapagos Islands with different beak shapes. When resources are scarse, a certain beak shape may allow a bird to access a food source that others cannot. Over generations, this selection creates a variety of beak shapes, each specialized for a unique food source.

In the following simulations there are three food sources: plants, insects, and seeds. Birds with long, narrow beaks are able to reach insects burrowed into trees, but cannot crush seeds. Birds with short, strong beaks are able to crush seeds, but cannot reach insects. All birds are able to eat plants.

As traits are naturally selected and specialization occurs, the differences within a population may become so great that they can no longer interbreed or share genes and therefore cannot be considered the same species. In the next simulation, when traits diverge to either solid red or yellow (longest or shortest beaks), they are no longer considered the same species.

A physical barrier, such as a mountain range, often effects speciation rates because it can limit crossbreeding between diverging traits. There are three modes of speciation, each regarding the physical location of diverging populations.

Allopatric Speciation
Diverging populations are completely geographically isolated from one another.

Parapatric Speciation
Diverging populations are somewhat isolated from one another, but contact and inter-breeding may still occur.

Sympatric Speciation
Populations continuously occupy the same space while diverging.

The previous page was an example of sympatric speciation because all the birds occupied the same location. The following page will demonstrate allopatric and parapatric speciation.