1. Speciation

2. Adaptation What do you think about when you see the word adapt?
Suitable
How did organisms become suitable to their environment?
Polar bear and the artic cold
Cactus and the desert heat
Variation leads to adaptation

3. Adaptation How do variations occur? Variation versus adaptation
Mutations. Specifically, mutations that can be passed on to the offspring.
Variation versus adaptation
Variation may or may not improve survival
Adaptation are variations that increase survival
Therefore adaptation is evolution through natural selection

4. How can adaptation leads to isolation?
What does Isolation mean???
Reproductive Isolation
Cannot interbreed with another species
Types of reproductive isolation
Behavioral – mating rituals
Geographic – different places or locations
Temporal – different times or seasons

5. Behavioral Adaptations
Any type of behavior that benefits an organism in their environment
For example
Migrating geese
Mating dances
Hibernation

6. Adaptations
An organism does not have just one form of adaptation for reproductive isolation. Instead, organisms have a combination of ways.
Let’s look at this example

8. Adaptation
If organisms can adapt to their environment, how did we get a large number of different organisms (species)?
Species are organism that can breed and produce fertile offspring
Natural selection brings about adaptations. Over a long period of time, natural selection can lead to new species. Otherwise known as speciation.

9. What are the steps for speciation?
Founding organisms (like founding fathers and mothers) occupy a niche
The founding organisms must be separated from the rest of the population
Changes in gene pool
Relative frequency of the alleles must change
Reproductive isolation
They cannot interbreed anymore
The process of speciation happens over a long period of time

11. Gene Flow (Thick Arrow – High)
(Thin Arrow – Low)

12. Gene Flow (Thick Arrow – High)
(Thin Arrow – Low)

13. Gene Flow (Thick Arrow – High)
(Thin Arrow – Low)

14. Gene Flow (Thick Arrow – High)
(Thin Arrow – Low)

15. Gene Flow (Thick Arrow – High)
(Thin Arrow – Low)

16. Adaptive Radiation –the process of numerous species from a common ancestor introduced into an environment. Also known as divergent evolution
Example using islands

17. Mainland to island Species A started on the mainland
What happened over time?

18. Galapagos Finches

19. Island
Forms
Mainland
ancestor

20. Reproductive Isolation
Concept Map
Reproductive Isolation
results from
Isolating mechanisms
which include
Behavioral isolation
Temporal isolation
Geographic isolation
produced by
produced by
produced by
Behavioral differences
Different mating times
Physical separation
which result in
Independently evolving populations
which result in
Formation of new species