Speciation & Natural Selection

Speciation is

• Changes to a species over time.

• The formation of new and distinct species in the course of evolution.

• Changes to species at a particular location

• The formation of the same species in a new location.

Select correct statements about speciation.

• Occurs over generations.

• Would not occur without variation within the initial population.

• Isolation is not essential for speciation.

• Time it takes for speciation to occur depends on the rate of reproduction.

Explain what is meant by Selection Pressures.

Over time, Giraffes necks have increased in length. What is a potential selection pressure driving this change?

Define survival of the fittest.

There are several types of Dunnarts found in Australia. Sminthopsis crassicaudata and Sminthopsis macroura are two examples. Why do all Dunnarts not have the same scientific name?

Explain the difference between Geographical Isolation and Temporal Isolation and give an example of how both types may occur.

What impact does isolation have on a species?

According to natural selection, light colored tree trunks would favor

• Light coloured moths

• Dark coloured moths

• Red coloured moths

• Red and light coloured moths

Natural Selection is driven by a change in the environment and survival of the

• Earth

• Fastest

• Fittest

• Biggest