Where did we come from http xkcd com765

Where did we come from? http: //xkcd. com/765/

How do individuals and groups with different genes arise? Evolution…

Mutations: Sickle-cell anemia CB 17. 22

CB 23. 17 Correlation of malaria and sickle-cell anemia

Does evolution occur?

As DNA changes; traits change. Protein

Evolution: A species’ genetic component changes as the individuals reproduce.

Evolution: A species’ genetic component changes as the individuals reproduce. These changes are based on how the DNA changes and who reproduces.

Reproductive success = evolutionary success

Fig 22. 19 How does evolution occur?

Natural Selection: Individuals that are most successful at reproducing will pass on more of their genetic information.

Individuals are selected… But populations evolve via changes in DNA during reproduction.

Evolution: A species’ genetic component changes as the individuals reproduce. These changes are based on how the DNA changes and who reproduces.

Evolution: changes in DNA as information transmitted O O O O Bacteria with mutation causing resistance O O O

Evolution: changes in DNA as information transmitted O O O O Bacteria with mutation causing resistance O O O Apply antibiotic X X X X X O O O Kills most bacteria. Except if some have mutation that allow them to be resistant.

Evolution: changes in DNA as information transmitted O O O O Bacteria with mutation causing resistance O O O Apply antibiotic O X X X X X O O O Kills most bacteria. Except if some have mutation that allow them to be resistant. Continues to replicate

Evolution: changes in DNA as information transmitted O O O O Bacteria with mutation causing resistance O O O Apply antibiotic Continues to replicate O X X X X X O O O Kills most bacteria. Except if some have mutation that allow them to be resistant. O O O O O Population of resistant bacteria

Reproductive success = evolutionary success

Natural Selection: Individuals that are most successful at reproducing will pass on more of their genetic information.

Evolution happens to populations; individuals O O O are selected O O O O Bacteria with mutation causing resistance Apply antibiotic Continues to replicate O X X X X X O O O Kills most bacteria. Except if some have mutation that allow them to be resistant. O O O O O Population of resistant bacteria

Genetic diversity is needed so selection can O O O occur O O O O Bacteria with mutation causing resistance Apply antibiotic Continues to replicate O X X X X X O O O Kills most bacteria. Except if some have mutation that allow them to be resistant. O O O O O Population of resistant bacteria

Fig 24. 15 Evolution has no goal. . . no ultimate life form wrong right

Flowering plants: Animal pollinators move pollen from one plant to another Plants reproduce, reward animals with sugar

Evolution does not always go “forward”… Some flowering plants disperse pollen by wind Fig 38. 4

Fig 24. 15 Evolution has no goal. . . no ultimate life form wrong right

Fig 25. 14 Evolution does not always occur at the same rate.

Fig 25. 14 The rate of evolutionary change depends on the rate of environmental change.

Environmental changes drive evolution.

We do not know what caused the largest extinction event known. Fig 25. 14

Fig 25. 14 Dinosaur extinction

Fig 25. 15 an Asteroid impact, 65 mya

Environmental changes drive evolution.

Humans can select beneficial traits: =Artificial Selection

Fig 38. 16 from Teosinte Maize By artificial selection that began ~10, 000 years ago.

Wild member of Brassica oleracea: small side buds Brussels sprouts: extremely large side buds

Wild Brassica oleracea: small side buds Brussels sprouts: extremely large side buds Selection only works if there is variability in the population

Artificial Selection (breeding) Hunter. Gatherer Industrial Agricultural

Different foods from one species of plant. Created by artificial selection. Fig 22. 9

Modern cows were bred from earlier bovine species.

Fig 25. 7 History of Earth: humans are a very small blip

Life as we know it… Fig 26. 21

In class activity #3 Gather around someone with a computer. Find a popular article (not from a scientific journal) related to evolution. What article did you use? How is evolution portrayed? What misconceptions about evolution can you find in this article?

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