Question

speciation
a gene pool is the combined genetic information for a particular population of organisms. each species has a common gene pool, although they may be separated into populations in which these genes are not able to be shared. if the gene pool of two populations are separated and the genes are no longer able to be shared through reproduction, the populations may develop into new species. this is known as speciation. these new groups will adapt to their environments as separate units, which may cause natural selection to heighten their differences over time.
isolating mechanisms
speciation may occur through a few ways including:

• behavioral isolation- the two populations are incapable of interbreeding due to differences in courtship or reproductive behaviors
• mechanical isolation- the reproductive organs of the two groups have become so different that they can no longer mate.
• temporal isolation- the populations mate at different times or seasons
• geographic isolation- the populations have been separated by geographic barriers (rivers, mountains, or roads) that prevent reproduction

discussion questions:

1. look at the picture at the top. this is called a \wildlife overpass\. what type of isolation are engineers and ecologists trying to prevent with this structure?
2. what is the disadvantage of isolating populations? (hint: how does the gene pool change after isolation and why might this be a problem?)

Explanation:

1. A wildlife over - pass is built to allow animals to cross roads. Roads are a type of geographic barrier. So, engineers and ecologists are trying to prevent geographic isolation.
2. When populations are isolated, the gene pool becomes smaller as there is no gene flow between populations. This reduces genetic diversity, making the populations more vulnerable to diseases, environmental changes, and genetic disorders.

Answer:

1. Geographic isolation
2. Reduced genetic diversity due to lack of gene flow makes populations more vulnerable to diseases, environmental changes, and genetic disorders.