Evolution- “Change Over Time”. All of the changes that have occurred in living things since the beginning of life on Earth. Theories of Evolution. Darwin vs. Lamarck. Lamarck. Darwin. Jean-Baptiste LaMarck. French, Early 1800’s Theory of Inheritance of Acquired Characteristics
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All of the changes that have occurred in living things since the beginning of life on Earth
Darwin vs. Lamarck
“Survival of the Fittest”
An example of Adaptive Radiation
Using Darwin’s Theory, explain how all of these different species evolved.
“Seeing this gradation & diversity of structure in one small, intimately related group of birds, one might really fancy that from an original paucity of birds in this archipelago, one species had been taken and modified for different ends.”
These organisms share?
What common ancestor do the seed eating and cactus eating finches share?
What do each of the finch pictures on here represent?
are spit In two due to a geographic barrier. This can lead to reproductive isolation. How could this lead to speciation?
If members of a species live far away from each other, they will have a decreased chance of mating. This would create reduced gene flow, but not total isolation. Speciation would probably also require different selective pressures at the two ends.
Eventually, this could alter gene frequencies in groups at different ends of the range so much that they would not be able to mate if they were reunited…that’s speciation!
MECHANISM OF EVOLUTION
Genetic Drift occurs when the frequency of alleles change
(NOT natural selection)
Newly Established Population
G H Hardy – British Mathematician
Wilhelm Weinberg – German Doctor
If we are evolving…
If we are not…
Using the example of the west nile mosquitoes that are sprayed with a pesticide, suppose one mosquito has a genetic mutation that allows the mosquito to survive. Which graph best represents the frequency of this gene over time?