Speciation

1
Speciation

• Chapter 16 Section 3

2
Speciation-The Formation of a New Species

• Common ancestors arrive in an environment.
• There is diversity in the gene pool causing a
  variety of phenotypes.

3

• Geographic isolation
• Due to competition members of a population are
  driven to different locations.
• i.e. The other side of the river, another
  island, out of the forest and into the
  desert

4

• Changes in the Gene Pool.
• Due to differing environments, the phenotypes
  that are naturally selected for are different for
  each environment.
• Each population drifts towards its own fittest
  phenotypes

5

• Reproductive isolation
• After many generations of Natural Selection
  leading the two populations of organisms towards
  different phenotypes, the two populations are no
  longer able to reproduce with each other.

6

• Ecological Competition
• Even if the two populations begin to mix in the
  same environment again, their phenotypes are so
  different that competition drives them towards
  different behaviors and food sources.

7

• Continued Evolution
• As the generations pass, the phenotypes
  continue to drift apart, as the behaviors and
  food sources are not similar.

8

• Write a paragraph explaining how the speciation
  of the two tortoises on the Galapagos Islands may
  have evolved from the same ancestor.