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Evolution of Aging and Late Life. Chapter 18 Experimental Evolution. Does aging have a purpose ? Is it adaptive ?. What is aging ? Think-Pair-Share. Does natural selection act on aging?. Does aging evolve ?. What is aging to an evolutionary biologist ? Think-Pair-Share.
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Evolution of Aging and Late Life Chapter 18 Experimental Evolution
Does natural selection act on aging? Does aging evolve?
We used to think… …aging evolved to eliminate older individuals to make way for the young. Why is this false? Think-Pair-Share
What are the evolutionary theories of aging?
Hamilton’s Forces of Natural Selection The force of natural selection acting on survival falls with adult age.
If natural selection isn’t acting on aging, does aging evolve?
How can we test theories of aging? If Aging has evolutionary basis • 1.) Early reproduction will accelerate aging in population. • 2.) Late reproduction will slow aging in population.
Well established laboratory organism • Used in experimental evolution studies • Short life-span • Easy to manipulate Model Organism Drosophila melanogaster
Results show aging is evolutionary Drosophila melanogaster
How many life stages do you see represented in this graph? Think-Pair-Share
Discovery of Late Life • An evolutionarily distinct phase of life • Evolves with different rules than those of early life and aging.