speciation and extinction
describe 2 examples of adaptive radiation
1. arrival of mammals, once the dinosaurs went extinct the mammals adaptive radiated to fill a bunch of niches that were once filled by dinosaurs 2. in the Galapagos as they move from island to island like the finch, which is 1 population
list ten possible causes of the mass extinctions
1. volcanos 2. pangaea 3. comet 4. CO2 5. gamma rays 6. sea level 7. climate change 8. methane hydrate 9. ocean radiation 10. ocean anoxia
how many mass extinctions has earth experienced?
5
why is there so much diversity among honeycreepers in hawaii
adaptive radiation
describe what scientists suspect happened during the K-T extinction. what evidence do they have for this?
an asteroid landed in the gulf of mexico that made them go extinct. below the kt boundary there is a dinosaur fossil but above it there are no dinosaurs. however, there is also a level of iridium that goes around the places that are very rare to our planet earth but common in asteroids
define extinction
how we go from one species to no species
define speciation
how we go from one species to two
what does extant mean?
species that are alive today
how is the interaction between dragonfly larva and sticklebacks an example of natural selection?
the dragonfly preyed more upon the fully armored sticklebacks than the low armored