1)Describe how geographic isolation can result in the formation of two distinct species.

2.Explain why geographic isolation of a population does not have to be maintained forever for speciation to occur.

Grand Canyon

The Grand Canyon in Arizona serves as a barrier to gene flow. While birds easily cross the Grand Canyon, it is impassable to rodents. As a result, the same bird species inhabit either side of the canyon, yet different species of squirrels inhabit opposite sides of the canyon.

With respect to the different populations, the Grand Canyon is

a.) a biological barrier to the squirrels

b )a biological barrier to the birds

c) a geographical barrier to the birds

d) a geographical barrier to the squirrels.

 

Answer:

1.Describe how geographic isolation can result in the formation of two distinct species.

-> To begin with, geographic isolation means separation of a species into two different population due to physical barrier. The population of a species will adapt to its habitat to live. Let's look back on the natural selection where the geographic location of a species will set the settings for the animals, and those who can adapt will be the only one who will continue live. It will only from small characteristic mutation then if we combine all those mutations it might result into a new species, which have physical characteristics suitable on that specific location. For example, if the nuts on the west have thicker shell than on the east, then the squirrels on the west might evolve with a larger or thicker teeth.

2.Explain why geographic isolation of a population does not have to be maintained forever for speciation to occur.

-> It is because once they have mutated, their genes is already built up. If an animal mutated, its mutated genes can be passed on its offspring and its offspring will passed it on second generation offspring. Even environment changes, this process will continue and make a new population of animals having the mutated genes.

Grand Canyon

The Grand Canyon in Arizona serves as a barrier to gene flow. While birds easily cross the Grand Canyon, it is impassable to rodents. As a result, the same bird species inhabit either side of the canyon, yet different species of squirrels inhabit opposite sides of the canyon.

With respect to the different populations, the Grand Canyon is

d) a geographical barrier to the squirrels.

-> The squirrels will adapt on the topography, condition, climate,etc. of its habitat. Consider the natural selection on this one, the two sides of Grand Canyon have different set of conditions and topography. For example, if west side of Grand Canyon have more predators, hotter temperature, thick nutshells, and have a river, then squirrels on this side will mutate and will have more defense mechanisms, shorter hair, larger teeth and swimming abilities compared to those living on the east.