1. Mechanisms of Evolution Speciation Through Isolation Patterns of Evolution

2.  1776 United States Became Independent ◦ Where were the original settlers from?  Was there an abundance of variation in this population?  How has immigration had an effect on genetic variation in the US? ◦ Leads to increased genetic variation in the population by adding new alleles to the gene pool.

3.  Defined: ◦ The movement of alleles from one population to another.  Break it Down: ◦ New Alleles to new population, loss of alleles in another.  Increases genetic variation.  How does it affect nearby populations?  What does a lack of gene flow lead to?

4.  Small populations more likely to be affected by random chance.  Allele frequency changes due to chance is called genetic drift.  Two processes cause pop. to become small enough for this phenomenon: ◦ Bottleneck effect ◦ Founder Effect

5.  Defined: ◦ Genetic drift that occurs after an event greatly reduces the size of a population.

6.  Genetic drift due to a small number of individuals of a population colonizing a new area.

7.  Loss of genetic variation. ◦ Less likely to be able to adapt to changes  Lethal alleles can become more common in gene pool.

8.  Males: ◦ Sperm production is constant,.: they are less selective in the mate they choose. ◦ More chances = less selective  Females: ◦ Production is limited in every reproductive cycle. ◦ Less chances = more selective.  Sexual selection: ◦ Certain traits increase mating success.

9.  Intrasexual: ◦ Competition among males.  Intersexual: ◦ Males display traits that attract female. ◦ http://dsc.discovery. com/videos/planet- earth-jungles-birds- of-paradise.html http://dsc.discovery. com/videos/planet- earth-jungles-birds- of-paradise.html ◦ Some traits are not adapted for survival.

10.  The sun’s surface is approx: 5505 degrees Celsius. Keep this in mind.  If you are standing next to a hot stove you can feel the heat.  As you get farther away you should feel less heat.  That is basic science, the farther you are from a heat source the less it affects you.  The Solar Corona (an area not to far from the sun) has a temperature of 1.5 million degrees Celsius.  How is this possible?

11.  How do we know that a miniature poodle and a great dane are the same species?  At what point would the two breeds become separate species?

12.  If gene flow stops, populations are isolated.  Adaptation is never ending ◦ Leads to gene pool changes.  Over time, changes add up & isolated populations become more and more genetically different  Behavior and phenotypes may change as well.

13.  Defined: ◦ When members of different populations can no longer mate successfully with one another.  Analyze: ◦ The final step in becoming separate species.  Discuss: ◦ Talk with your neighbor for 1 minute and come up with an example of Isolation in nature. Be prepared to share! 60 Seconds starts NOW!

14.  Defined: ◦ The rise of two or more species from one existing species  BUT Mr. Wilson…..! ◦ How does isolation occur so that new species can be formed?! ◦ Great Question! There are three ways that populations can become isolated! Behavioral Barriers Geographic Barriers Temporal Barriers Socially Awkward Penguin

15.  Behavior changes can prevent mating between populations.  Defined: ◦ Isolation caused by differences in courtship or mating behaviors.  Examples: ◦ Fireflies flash patterns ◦ Chemical scents ◦ Courtship songs/dances with birds

16.  Defined: ◦ Physical barriers that divid a population into two or more groups.  What kind of barriers you ask? ◦ Rivers, mountains, rivers, anything!  Examples: ◦ Pacific/Atlantic species separated by the Panama Isthmus  Shrimp ◦ Grand Canyon & Squirrels Just pretend they’re shrimp OK?!

17.  Defined: ◦ When timing prevents reproduction between populations.  Courtship period ◦ Time of Day ◦ Time of Year ◦ Based on competition  Example:

18. American Toad Mates Early Summer Fowlers Toad Mates Late Summer

19.  No Guarantees & You Have to Be Good at Math!  Pick a Number between 1 and 10.  Multiply it by 9  Add the two Digits of the resulting number together (if you picked 1 just deal with it)  Now Subtract 5 From it….  You should have a number now…think of the corresponding letter in the alphabet (A=1, B=2, etc.)

20.  Pick a country that starts with that letter. Any Country… So if you had F, Finland would work.  Once you have your country use the last letter of that country and think of an animal. Finland = D = Dog  Once you have your animal take the last letter of that animals name and think of a color. Dog = G = Green!  You Have it?....ok here I go…

22.  Mutation and Genetic Drift cannot be predicted. ◦ Random Events  Natural Selection is NOT random. ◦ Beneficial traits increase survival  Natural Selection has direction ◦ But this direction is controlled by the environment NOT the population

23.  Scenario: ◦ Zombie Apocalypse ◦ Zombies will also eat small rats ◦ Humans or Rats with tough skin pose a challenge to zombie rotted teeth. ◦ Both species begin to develop similar characteristics in their skin making it tougher. ◦ Convergent Evolution  Shark/fish tails, bird / butterfly feathers (analogous structures).

24.  Defined: ◦ When closely related species evolve in different directions.

25.  Sometimes a change in one species can result in a change in another.  Coevolution: ◦ The process by which two or more species evolve in response to changes in each other.  Example: ◦ Stinging Ants & The Bull-thorn acacia

26.  Competitive species can also coevolve: ◦ Plants developing defense chemicals to avoid consumption by herbivores. ◦ Crabs eat snails  snails develop bigger spiked shells  crabs develop more powerful claws … etc

27.  Defined: ◦ The elimination of a species from earth.  How? ◦ Failure to adapt, hunting, fishing, etc.

28.  Punctuated Equillibrium ◦ Episodes of speciation occur suddenly ◦ Followed by long periods of little evolutionary change.  Adaptive Radiation ◦ Diversification of an ancestor into many descendant species.