1. Finishing Off Evolution! Agents of Evolutionary Change
Migration, Non-Random Mating, Selection Types

2. Last Class Discussed 2 agents of Evolutionary Change
We discussed the HWE… Which stands for…?
The Hardy-Weinberg (Genetic) Equilibrium
Discussed 2 agents of Evolutionary Change
Mutations
Substitutions, Insertions, Deletions, Frameshifts
Neutral, Harmful, Beneficial
Genetic Drift
Bottleneck and Founders Effect
How small populations can be hit hard by evolution

3. Today Finish up Agents of Evolutionary Change As promised Migration
Non-Random Mating
Selection
As promised
Time IN CLASS to work on Build-a-beast project/ Evol. Research Project
Time IN COMPUTER LAB to work on Evol. Research Project

4. REMINDER EVOLUTION PROJECT PRESENTATION- TUESDAY MARCH 10.
IF it is an ELECTRONIC presentation PLEASE submit by MIDNIGHT MARCH 9!!!
EVOLUTION UNIT TEST- THURSDAY MARCH 12
Start preparing now.

5. Back to the Action… 1. No Net Mutations occur
Last class, we looked at the 5 assumptions of a hypothetical, “ideal” non-evolving population:
1. No Net Mutations occur
2. Individuals do not enter or leave the population
3. The population is large (ideally, infinitely)
4. Individuals mate randomly
5. Selection does not occur

6. Migration (Gene Flow)
2. Individuals do not enter or leave the population
Immigration  The movement of animals into a population
Emigration  The movement of animals out of a population
Both can play a role in gene frequencies

7. Migration (Gene Flow) Consider the Baboon
Common baboons live together in groups called “troops”
Troops are dominated by a small number of adult males.
Females remain with troops they are born into, but young adult males tend to leave their birth troop, and join another troop.
This disrupts the genetic variation in the original population, as well as the immigrated population

8. Non-Random Mating Most species undergo some process of mate selection
Usually due to geographic proximity, and some degree of kinship

9. NON RANDOM MATING
Mating between closely related individuals can amplify certain traits, resulting in disorders caused by recessive genes
Animals will often seek out mates with similar physical traits, meaning they will have similar genes
This is known as Assortive mating

10. Sexual Selection (Goes with non-random mating)
Consider the feathers of the peacock
Very easy for predators to see
Why would these be advantageous?
A male must be “selected” by a female. Big elaborate feathers, or other traits are a sign of an organisms health and fitness
Represents good genes, and are selected by females.

11. Natural Selection
The fifth requirement of the HWE was that Selection does not occur in a population
Natural selection is a key process in which the environment “selects” for certain traits (genes) to be passed on to the next generation
Three Selection patterns:
Stabilizing, Directional, Disruptive

12. Stabilizing Selection
Individuals with the average form of a trait have the highest fitness.
Ex. A species of lizard in which larger individuals would be spotted easily by predators, and smaller species are not fast enough to escape predators

13. Stabilizing Selection Fig 16.7a

14. Directional Selection
Individuals that display a more extreme form of the trait will be selected.
Ex. The length of an anteaters tongue. The longer the tongue, the more insects they would be able to eat which were buried deeper in the ground.

16. Disruptive Selection
Individuals with EITHER EXTREME of the trait will have more fitness than the average form of the trait
Ex. Shell color of a clam. Individuals who are dark are able to camouflage themselves in dark rock or in shadows, individuals with light colouring will be able to hide in the light coloured sand. Individuals that are between light and dark will not be able to hide as easily.

19. And That wraps up Evolution!
To do now:
16.2 Review Sheet in front of you
Finish Chapter 15 Review in back of textbook
Finish any journal entry you are behind on/ want to finish off (They will be given a completion mark at the end of the Evolution Unit)
Work with your groups to finish:
Build-a-beast project
Evolution Research Project
Study for DNA retest/Evolution Unit Test