Question

9. A flowering plant species grows on the mainland near the coast. One summer, a tropical storm
blows seeds from this population several hundred miles out to sea. Some of the seeds land on an
island, where they form a new population. Describe two ways that speciation could occur in this
situation. Include the concepts of genetic drift, gene pool, reproductive isolation, and selection in your
description.

Answer 1

The two possible types of speciation could occur in this situation are allopatric or peripatric speciation.

Allopatric speciation or geographic speciation

This type of speciation occurs when biological populations of the same species become isolated due to geographical changes. The two populations of the flowering plants are separated by geographical barrier (sea), prevents the gene flow between the populations and thereby, reproductive isolation will occur. Due to the lack of mating between two populations, sterility or environmental barriers eventually lead to the adaptive splitting into two species.

The genetic drift and selection will act differently on these two different genetic backgrounds, creating genetic differences between the two new species.

Peripatric speciation

The seeds land on the island forms a new population of flowering plants and are prevented from exchanging genes with the main population because, the small groups of individuals are breaked from the main population. Due to genetic drift, the change in gene pool of population occured by chance, and the species that are selected to survive on island.