ES101 Lecture Notes - Lecture 6: Tetraodontidae, Tetrodotoxin, Gene Pool
Document Summary
Evolutionary processes: theory of evolution, darwin, scientific explanation, finches. Resistance to puffer fish poison - tetrodotoxin - ttx. Divergent evolution: single species into variety of similar species, specialized niches, darwin finch - beaks. Convergent evolution: distantly related groups of organisms, develop similarities - adapt to similar environment. Species acquire traits to allow survival in their environments: limited range of physiological modifications, gradual and incremental. Speciation: two species from one, each suited to specific environmental conditions, lots of species. Types of speciation allopatric: geographic isolation, migration, physical barriers, glaciation, sea level change, reproductive isolation, divergence in genetic makeup. No interbreeding - mutation or behavioural change. Downloaded by jj jj (iabonijordan@gmail. com: disappearance at low rate, 1-5 species for each million species. Mass extinctions: catastrophic, widespread - global, 20-25% loss. Factors that increase diversity: physically diverse habitat, moderate disturbance (fire, flooding, small variation in environmental conditions (temperature, precipitation, middle stages of succession.
