Lesson 1: Introduction to Evolution Flashcards
what did leclerc de buffon do
he studied anatomy and examined body structure and function
- he was confused by anatomical features that held no purpose, for instance, the toe in pigs that do not touch the ground
what did leclerc de buffon believe/hypothesize?
that species had been created in a more perfect form but changed over time
what other prominent scientists added onto leclerc’s idea?
- charles linnaeus said that life changed over time
- erasmus darwin suggested that all life might have evolved from a single original source
chevalier de lamarck proposed what principals?
- use and disuse: structures that an individual used, became larger and stronger and structures that were not used got smaller and weaker
- inheritance of acquired characteristics: individuals could pass characteristics onto their offspring that they had aquired over their lifetime
issues with lamarck’s theory?
- we know that traits can change over an individual’s lifetime, but that does not change their DNA or how their traits are passed on
EX: a giraffe cannot “stretch” its neck over its life and pass on the trait of a longer neck to its offspring
who made the origin of species book and what did it suggest
darwin created this book, and it proposed a theory of how species evolved
- darwin described natural selection as a way in which the environment favours the reproductive success of certain individuals over others
- evolution was simply the result of natural selection occurring over many generations
what key observations did darwin make in his theory, and what did he conclude from this?
observations:
- all healthy populations produce far more offspring that can survive
- all individuals exhibited heritable variability
conclusions:
- some individuals will have better chance of success than others
- their traits are therefore more likely to be passed onto the next generation
what does “survival of the fittest” describe in terms of evolution
the statement itself may be misleading- being “fit” is not whats important, being more likely to have reproductive success is!
what do the five fingers tell you about evolution?
The processes that cause evolution can therefore be represented by our fingers. Pinky= small population; ring finger= non-random mating; middle finger= mutations; pointer finger= gene flow
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