Topic: Other Mechanisms of Natural Selection Learning Target: Discuss mechanisms of evolutionary change other than natural selection such as genetic drift and gene flow.

Unit 1 Test Re-cap The graph below represents a change in event A that leads to changes in events B and C. Which row in the chart the the right best shows the correct sequence of events that are increasing or decreasing as show on the graph to the left? Directions: Complete all of the following for the question above. GIST: (In one sentence, explain what the question is about) (2 points) ___________________________________________________________________ CORRECT ANSWER: (1 point) EXPLANATION: (Why is this the correct answer?) (4 points) REFLECTION: (After grading this question answer the following) (3 points) I was CORRECT INCORRECT (Check one!) BECAUSE _____________________________________________________________ http://video.nationalgeographic.com/video/worlds-deadliest/deadliest-cheetah-gazelle

Student, What did we talk about last class? Student, can you add anything else to that? Student, what was the formula to Differential Selective Success?

Write what is in Red...

Other Mechanisms of Evolution Gene Flow Genetic Drift Nonrandom Mating Mutations

Gene Flow: the exchange of genes due to migration Mutations occur over time. They are natural and produce genetic diversity that is needed for survival.

Student, how does gene flow lead to the evolution of a population? Student, Can you add anything to what that student said? Student, can you unpack what they both just said? DO YOU THINK GENE FLOW HAPPENS IN HUMANS?

Do you support or challenge what they just said? Why? Student, can this happen in all populations?

Microevolution 10/27/15 Gene Flow in Plants G. Podgorski, Biol. 1010

Microevolution 10/27/15 Gene Flow in Humans G. Podgorski, Biol. 1010

Microevolution 10/27/15 2. Genetic drift: the change in the gene pool of a population due to a random occurrence. G. Podgorski, Biol. 1010

Student, how does genetic drift lead to the evolution of a population? Student, Can you add anything to what that student said?

Example of Genetic Drift

Genetic Drift Example Northern elephant seals have reduced genetic variation because humans inflicted on them in the 1890s. Hunting reduced their population size to as few as 20 individuals at the end of the 19th century. Their population has since rebounded to over 30,000 but their genes still carry the marks of this predation. They have much less genetic variation than a population of southern elephant seals that was not so intensely hunted.

Student, do you support or challenge what that student just said? Student, do you think there is a lot of genetic variation in the heavily predated seals? Student, do you support or challenge what that student just said? Student what does it mean in the long run for the heavily predated seal population in terms of their genetic variability Student, do you think this makes their population at risk for a natural disaster?

Difference in Genetic Drift and Gene flow... Student, what is the difference between genetic drift and gene flow Student, can you add anything to what the student said.

3. Non-Random Mating A situation where mates are chosen for one another or by another pre-determined factor. Leads to a loss of gene variability! Many plants self-pollinate, which is also a form of non-random mating (inbreeding).

Non-Random mating Student, can this mechanism happen in humans? Do you support or challenge what student said?

Sexual selection occurs when certain traits increase mating success.

4. Mutation Introduce new traits into a population. Ex?

Study for BIO-BLITZ If you have not looked at the words on the class instagram you need to… Also review all words in your notebook

Output 4 minutes... Florida Panthers are an endangered species at risk for extinction. The gene pool of the panthers is very small, and as a result, all of the individuals are vulnerable to the same diseases because there is not enough variation. Scientists decided to try to save the Florida panthers by introducing new genes into their population. Scientists placed a similar breed of panther from Texas into the Everglades, in hopes that the panthers from Texas would breed with the Florida panthers and increase the gene pool. However, the Florida panthers only mated with other panthers in the original population. After a few years, a Category 5 hurricane swept through the Everglades, killing 90% of the original Florida panther population but only 10% of the new panther population from Texas. Gene flow=introducing panthers from Texas Genetic drift= hurricane randomly killed most of the original population non random mating=florida panthers would not mate with texas panthers

Questions What part of this story is an example of gene flow and why? What part of the story is an example of genetic drift and why? What is an example of non random mating and why? Using what you know about evolution, what do you predict will happen to the population of panthers?

Go the 3 stations you have 5 minutes per station. Listen for the timer We do…. Go the 3 stations you have 5 minutes per station. Listen for the timer

You have 10 minutes to answer the 6 questions. Independent Practice You have 10 minutes to answer the 6 questions. 2 are short response Raise your hand if you have any questions

5 minutes to take this quiz You will do great!!!!! Exit ticket Put all notes away!!!!! 5 minutes to take this quiz You will do great!!!!!