Macroevolution, Broad changes in organisms above the species level, Stromatolites, Fossils formed by the accumulation of sedimentary layers on bacterial mats, Permian mass extinction, An extinction event 252 MYA due to volcanic activity and global warming which caused oceanic anoxia, Cretaceous mass extinction, An extinction event 65 MYA due to the impact of a meteorite which caused dust clouds and disturbed global climate, Adaptive radiation, The evolution of many diversely adapted species from a common ancestor, Speciation, The process by which one species splits into two or more species, Microevolution, The change in allele frequency in a population over time, Hybrid, The offspring of crosses between two different species, Prezygotic barriers, Barriers that block fertilization from occuring, Habitat isolation, Two different species do not interbreed because they occupy different habitats, Temporal isolation, Two different species do not interbreed because they breed at different times of day/season, Behavioral isolation, Two different species do not interbreed because they have different courtship rituals, Mechanical isolation, Two different species do not interbreed because there is a physical or biological structure that prevents mating, Gametic isolation, Two different species do not interbreed because their sperm and eggs are incompatible, Postzygotic barriers, Barriers that prevent the hybrid zygote from developing into a viable, fertile adult, Reduced hybrid viability, Two different species create a hybrid, but it doesn't survive development, Reduced hybrid fertility, Two different species create a hybrid, but it is sterile, Hybrid breakdown, First generation hybrids are fertile and healthy, but second and third generation hybrids are less healthy, Allopatric speciation, Occurs when a population is separated into two groups by a physical barrier, Sympatric speciation, Occurs when a population is separated into two groups due to polyploidy, habitat differentiation, or sexual selection, Hybrid zone, A region where members of different species mate and produce hybrids.

Unit 7.2: Speciation

by
Print
Embed

Leaderboard

Visual style

Options

Switch template

)
Continue editing: ?