MACROECONOMICS Chapter 7 Economic Growth I: Capital Accumulation and Population Growth.
EVOLUTION Accumulation of inherited changes within a population over time.
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Transcript of EVOLUTION Accumulation of inherited changes within a population over time.
Pre-Darwinian IdeasPre-Darwinian IdeasDarwin was not 1st to propose
theory of evolution
Aristotle (4th century BC)◦Life extended from simple to complex
◦Imperfect but moving toward perfection
◦No mechanism for HOW
Jean Baptiste de Lamarck (1744-1829)
◦1st to propose that organisms undergo change over time as a result of natural phenomena
◦Use and disuse
◦Theory of acquired characteristics
◦LAMARCK WAS WRONG IN MECHANISM
Influences on DarwinInfluences on DarwinCharles Lyell and James Hutton
◦Earth much older than people thought
Darwin’s Theory of Evolution by Darwin’s Theory of Evolution by Natural SelectionNatural SelectionIn struggle for survival, favorable
traits preserved, unfavorable ones eliminated◦Adaptation
Natural Selection – best adapted organisms survive and pass on their traits, population changes over time◦Fitness
4 aspects of natural world on 4 aspects of natural world on which Darwin based his theory:which Darwin based his theory:
Overproduction
Variation
Limits on population growth
Differential reproductive success
What Natural Selection is What Natural Selection is NOT:NOT:Natural Selection is not a CHOICE
Natural Selection is NOT BASED ON NEED
Natural Selection is not a MUST
Modern SynthesisModern SynthesisMendel’s work (1860s) not
recognized until 20th century
1930s-40s – biologists combined Mendelian inheritance with Darwinian Evolution◦Mutations are source of variation◦Continue to try to understand causal
processes of evolution