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More embryo examples. Darwin Goes Sailing. And finds finches!. More finches. Natural Selection. In 4 easy steps! Overproduction Genetic variation Struggle to survive Successful reproduction. 1 . Overproduction. Why is over-production important? - PowerPoint PPT Presentation
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Darwin Goes SailingDarwin Goes SailingAnd finds finches!
More More finchesfinches
Natural SelectionNatural SelectionIn 4 easy steps!In 4 easy steps!
1.Overproduction2. Genetic variation
3. Struggle to survive4.Successful reproduction
11. Overproduction. OverproductionWhy is over-production important?
For example, a rabbit can have a litter of 4 babies every month.
In one year, a rabbit can produce 48 babies!If they all have babies the next year, how
many babies would that be?
2. Genetic Variation2. Genetic VariationWe’re all unique!
3. Struggle to 3. Struggle to SurviveSurvive
Organisms must• Escape predators• Find food• Conserve energy• Find mates
4. Successful 4. Successful ReproductionReproduction
Why is this important?
How does evolution How does evolution happen?happen?
One way is by “genetic drift”Examples:HorsePeppered moth
How does evolution How does evolution happen?happen?
An important factor is ISOLATION.The same species, in different
environments, can evolve differently. This is how one common ancestor can evolve into several different species.
Divergent evolutionDivergent evolution
Founder effectFounder effectIf only a small population is available to breed, the distribution of traits changes.
MutationsMutationsCan be deadly, either prior to birth
(miscarriage), or shortly after.
Lethal white syndromeRye nose
MutationsMutationsCan be neutral:CGUCGCCGACGGAGAAGG
All code for Arginine.
What if you suffered a mutation that
effected the development of
your gill slits?
MutationsMutationsCan be harmful but not deadly:Down’s syndromeMarfan’s syndromDwarfismPolydactyly
MutationsMutationsCan be good!Bohlinia Samotherium Giraffe!
Sickle cell anemia???
Giraffe LawsGiraffe LawsIn Atlanta, Georgia, it is illegal to tie a giraffe
to a telephone pole or street lamp.
In Idaho Residents may not fish from a giraffe's back.
No, this has nothing to do with science.
Lack of EvolutionLack of EvolutionThe Hardy-Weinberg Principle:Will occur if the population is • infinitely large• isolated from other populations• mating is random• all genotypes are equally viable
Lack of EvolutionLack of Evolution1. Extinction
2. Lack of need to change:• Sharks• Horseshoe crabs• Cockroach
More about Natural More about Natural SelectionSelection
http://evolution.berkeley.edu/evolibrary/article/sneakermales_01
