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Evolution in Process 15.3 pp. 289-292. Evolution is a continuous process that is always going on, just really slowly (needs lots of time). Evolution in Process 15.3 pp. 289-292. Homologous structure = similar feature found in many different species Comes from some common ancestor
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Evolution in Process 15.3 pp. 289-292 Evolution is a continuous process that is always going on, just really slowly (needs lots of time)
Evolution in Process 15.3 pp. 289-292 Homologous structure= similar feature found in many different species • Comes from some common ancestor • Examples: different beaks for different birds • Forelimbs (arms) in high order animals • Similar species,different job
Evolution in Process 15.3 pp. 289-292 Analogous structure = feature that does the same job but is very different in structure • Wings on birds (arms) vs. wings on insects (just wings) • Webbed feet on ducks vs. fins on fish • Different species, same job
Evolution in Process 15.3 pp. 289-292 Coevolution = 2 different species in close relationship that evolve together • Predator – prey : gazelle get faster to escape, cheetah get faster to catch the gazelle • Plant – pollinator: hummingbirds and the flowers they feed on
Evolution in Process 15.3 pp. 289-292 Convergent evolution = different species evolve features to do a similar job in a similar environment • The conditions they live in are similar so they need to do similar things to survive • Sharks – dolphins : these have converged • Different species, same job What does it mean to converge? Related to analogous structure.
Evolution in Process 15.3 pp. 289-292 Divergent evolution = very similar species evolve different features to do different jobs • Different habitats so they evolve different ways to survive • Sea snakes – desert snakes • Penguins -- ducks • Artificial selection: dog breeding, cattle breeding (these are done by humans, not nature) • Similar species, different job Related to homologous structure.
Evolution in Process 15.3 pp. 289-292 Examples of divergent evolution. Where on the graph to species diverge?