lesson 3 - evolution (decent with modification) Flashcards
homology in evolution
similarities in traits or structures between different species that arise due to their inheritance from a common ancestor
anatomical homology
similar body structures (e.g., human arm, cat leg)
developmental homologies
similarities in the developmental processes or embryonic stages of different species that result from their shared ancestry
who observed species adaptation to environements?
charles darwin
who believed species are perfect, permanent, and fixed on a scale of increasing complexity?
aristotle
what is scala naturae?
classified on a scale of increasing complexity (simple to complex species)
who developed the binomial among system?
carolus linnaeus
who is the father of modern taxonomy?
carolus linnaeus
what does jean-baptiste de lamarck’s “use and disuse” mechanism mean?
body parts used frequently become stronger, while those not used deteriorate
what is jean-baptiste second mechanism?
inheritance of acquired traits: traits acquired during an organism’s lifetime are passed to offspring
what is the significance of Darwin’s “On the Origin of Species”
introduced the concept of “Descent with Modification” and natural selection
what is convergent evolution?
unrelated species develop similar traits due to similar environmental pressures (do not share a common ancestor)
give an example of analogous traits from convergent evolution
wings of birds and bats, used for flying but evolved independently
natural selection
differential survival and reproduction of individuals based on variation in inherited traits
what does biogeography study?
long ago, all the continents were smushed together into one big land called Pangaea. overtime, the continents drifted apart. animals that lived on these continents got separated. this is why kangaroos only live in Australia because that continent drifted away.
who was Charles Darwin?
formulated the theory of “Descent with Modification” and the mechanism of natural selection
what are the four requirements for evolution by natural selection?
reproduction, variation in traits, heritability of traits, and differences in fitness related to traits
reproduction
must produce offspring
variation in traits
differences in how individuals appear (phenotypes)
trait differences are heritable
traits are passed from parents to offspring
variation in fitness
not all individuals succeed, and this variation is related to traits (some giraffes have longer necks)
what is “Descent with Modification”
the idea that species evolve over time from ancestral forms through changes in traits
what are vestigial structures?
a body part that no longer has a useful function but is leftover from an ancestor that needed it
what is adaptation?
a trait or characteristic that helps a living thing survive and reproduce in its environment
