Anthrbio 201 1st Edition Lecture 21. How Have Humans Evolved?2. Does Evolutionary theory shed light on contemporary human biology and behavior● Species have changed through time○ direct observations of evolutionary change: small scale changes in nature■ bighorn sheep (males are rams)■ artificial selection experiments○ trophy hunting acts as a selective agent- mean horn length (cm) has changed■ Ram Mountain, Alberta, Canada■ Shot for their horns; hunters shoot biggest horns (most shot before 8years old)■ Grow horns when between 2-4 years○ St. Bernard, Boston terrier = same species○ artificial selection has produced changes through a lineage of dogs● Species have a common origin○ nodes in diagram represent common ancestor○ species=units of analysis○ analogous features- genetic code is universal■ wings of bats, birds and insects■ vertebrate pendactyl limb (frog, lizard, bird, human) used for differentreasons but so similar in form○ Vestigial structures■ whales have similar bones as our hip/legsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.■ whales are mammals not fish, so they must’ve derived from a terrestrialancestor■ The valley of whales- Wadi Hitan, Egypt ankle bones reveal clearrelationship● What are species?○ reproductive isolation○ overall appearance■ chimpanzees and humans are very clearly different species becausehumans don’t try to mate with them and look different● There are gaps○ between fish and tetrapods for between 385 mya and 365 mya○ Tiktaalik- fish like features (fins, scales, gills) tetrapod (ribs, mobile neck, eyes)■ links aquatic life and terrestrial life● Evolution is real because○ direct observations and small scale changes in the natural world and producedby artificial selection and long term changes in fossil record○ argument from homology○ temporal order of animals in the fossil
View Full Document