Darwin Evoultions

• Evolution: Descent with modification
• Aristotle believed in no concept of evolution
• Linnaeus created system of naming and classifying organisms
• Cuvier: species disappeared and new appeared in rock layers. At each rock layer was a result of a catastrophe where many species were destroyed and new spp migrated.
• Hutton: gradualism, small changes over time
• Lyell: not only earth but also species change overtime
• Lamarck: use and disuse of traits, first to propose mechanism for evolution
• Acquired characteristics: body parts that are used will change
• Individuals acquire characteristics during lifetime and pass them to next generation
• Acquired traits cannot be inherited
• Darwin had two main conclusions: variation and over production
• Variation: many individuals in a population but none are the same, each have unique traits
• Differential reproductive success: individuals best adapted to environment are more likely to survive and reproduce
• Overproduction: all species can produce more offspring then environment can support due to limited resources
• Since there are limited resources, it causes competition between species.
• Not all survive to reproduce
• Natural selection is a mechanism of evolution
• Fitness: the ability to reproduce viable offspring who survive
• Evolution: populations changes over time
• Favorable traits increase in frequency over time
• less favorable traits become scare or disappear
• populations evolve individuals do not evolve
• Artificial selection = selective breeding : humans are agents of selection, only certain individuals reproduce, desirable traits passed on
• Direct observation: response to introduced species, species adapt to environment
• Homology: simliarity resulting in common ancestry
• Embryonic development : similarities in early development of different animals species because they share CA
• Vestigial organs: Undersized and not functional
• Fossil record : Remains/traits in sedimentary rocks