1. Different scales of evolution
Microevolution
Macroevolution
Speciation

2. Microevolution Change of the gene frequency in a population.
Frequency – how often something happens or occurs.

3. Causes of Microevolution
Natural Selection
Migration – movement of individuals into or out of a population
Mate Choice (sexual selection)– Parents select mates for a reason
Mutation – causes small changes in genes.
Genetic Drift – Random effects of everyday life (like being eaten, or starved)

4. Macroevolution
Changes above the species level

5. Types of Macroevolution
Convergent Evolution – Species living in similar environments develop similar adaptations.

6. Types of Macroevolution
Coevolution – Species in close contact develop adaptations to each other.

7. Types of Macroevolution
Adaptive Radiation – When new species enter an environment with few other species, they tend to change rather quickly.

8. Extinction
All members of a species die off or fail to reproduce.

9. Gradualism and Punctuated Equilibrium
Gradualism - Many small changes accumulate to make large changes over long periods of time. Punctuated Equilibrium – Species remain stable for long periods of time, then new species suddenly “appear.”

10. Gradualism and Punctuated Equilibrium

11. Speciation
The formation of a new SPECIES through evolution

12. But what is a species?

13. A horse and a donkey can breed and create mules
A horse and a donkey can breed and create mules. But mules cannot have babies.
Donkeys and Horses are different species.

14. A Great dane and a chihuahua can breed and make babies
A Great dane and a chihuahua can breed and make babies. And their babies can have babies.
Great Danes and Chihuahuas are the same species.

15. Lions and Tigers can breed and make a liger
Lions and Tigers can breed and make a liger. But Ligers cannot breed with eachother.
Lions and tigers are different species.

16. So based on those examples and non-examples discuss with your group and write down your own definition of what a species is.

17. Species
A group of individuals that are capable of producing FERTILE offspring in the natural environment.
The key word is Fertile offspring
A donkey and a horse can create a mule, but mules are infertile. Are horses and donkeys the same species?

18. Species
These happy face spiders look different, but can interbreed and create fertile offspring so they are the same species.

19. There are three things you need for speciation to occur…
Let’s read a couple stories to help us figure out what these are.

20. 1st thing you need for Speciation is Isolation
Separation of a formerly successful BREEDING population so they can no longer mate.

21. Separated PHYSICALLY from each other by topography.
Geographic Isolation
Separated PHYSICALLY from each other by topography.
Ex: Rivers, Oceans, Mountains

22. Geographic Isolation

23. Behavioral Isolation
These populations can still interbreed but they do not. They prefer their own population for a variety of reasons.

24. Behavioral Isolation
The fruit-flies on the bananas prefer the fruit-flies on the bananas.

25. Temporal Isolation
Animals breed at different times. Example: Different breeding seasons.

26. 2nd Thing you need is Adaptation
The isolation of populations causes them to change and adapt to their new conditions.

27. 3rd thing you need is Reproductive Isolation : When organisms can no longer breed and create fertile offspring
Rana aurora – Lays Rana boylii – Lays
Eggs in streams Eggs only in standing
water.

28. Extinction
When an entire SPECIES dies off.

29. Selective Breeding Also known as Artificial Selection
Humans choose which traits are passed on in organisms.
Examples include: Dogs, livestock, and many crops.

30. Artificial Selection Characteristics
Process driven by humans, not nature.
Humans don’t always pick the traits that are best for the organism. They pick the trait that is desirable to them.
Example: Bulldogs were artificially selected for by humans. Humans wanted a short, stocky dog, with lots of wrinkles, and flat nose. This causes the dog to usually have respiratory problems and usually have poor health in general.

31. Then

32. Now

33. Then

34. Now

35. Then

36. Now

37. Then
Removing Seeds

38. Then
Dehorning

39. Now
Polled

40. Selective Breeding
In what ways is selective breeding similar to natural selection?
In what ways is it different?