Chp 11.5 Speciation Through Isolation Study Guide Set

Which types of isolation can involve mating or courtship rituals?

Behavioral Isolation

What are the differences and similarities between behavioral isolation and temporal isolation?

Behavioral isolation involves differences in courtship or mating behaviors. Temporal isolation involves differences in the timing of courtship or mating behaviors.

What is behavioral isolation? Provide an example.

Changes in behavior between two populations can act as barriers which prevents mating. Example: Firefly species with different flash patterns, bird mating songs differ

What is temporal isolation? Provide an example.

Differences in mating periods or times of day when individuals are active can prevent mating between populations. Example: Plant species that shed pollen during different times of the year.

What is speciation?

Formation of new species from an existing species

Two populations are said to be isolated if there is no loner any __________ between them.

Gene Flow

Over generations the __________ of isolated populations may become more and more different.

Gene Pool

Which types of isolation can involve physical barriers?

Geographic Isolation

What are the three types of barriers that can lead to reproductive isolate?

1. Behavioral Isolation 2. Geographic Isolation 3. Temporal Isolation

Reproductive isolation is the final step of __________, which is the rise of a new ___________.

Speciation, species

Which types of isolation involves different factors of time?

Temporal Isolation

How did geographic isolation affect the diversity Darwin observed in Galapagos finches?

The geographic isolation of the finches on different islands meant that each island's environment selected for traits that were beneficial on that particular island. Over time, genetic differences accumulated in the isolated populations, leading to many distinct finch species.

Why is reproductive isolation considered to be the final stage in speciation?

When populations can no longer mate successfully with one another, they are considered to be separate species. Until this occurs, other forms of isolation can be overcome as long as the two populations can still interbreed and have healthy, fertile offspring.

How can a lack of gene flow between populations lead to speciation?

Without gene flow, the populations may begin to become more and more genetically different. They may become so genetically different that individuals from one population are no longer able to mate successfully with individuals from the other population. At this point, the two populations are different species.

Isolated populations may become genetically different as they adapt to new _________, or through random processes such as mutation and _______.

environments, genetic drift

How can reproductive isolation lead to speciation?

If populations cannot mate successfully with one another, genetic differences may accumulate in the populations. Over time, the populations may become so different that they become different species.

What is geographic isolation? Provide an example.

Physical barriers can divide populations. Example: Isthmus of Panama divides populations of marine species in the Atlantic and Pacific Oceans.

When members of two isolated populations can no longer ________________ successfully, the populations are said to be reproductively isolated.

mate