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Date: May 5, 2016 Aim #78: How does geographic and reproductive isolation lead to speciation? HW: 1)Relationships and Biodiversity Lab due Friday 5/6 3)Evolution Test Monday 5/9 and Tuesday 5/10 4)Unit 7e due Friday, May 13th –Do not forget Castle Learning!! –Human Phys. Fridays Do Now: Warm-Up Notebook DateTitle of Activity Page # 5/5Hardy-Weinberg Problems120
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Aim #78: How does geographic & reproductive isolation lead to speciation?
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1) Speciation Evolution has lead to the formation of new species from different ancient organisms. Species- a group of organisms that share certain characteristics & can mate with one another, producing fertile offspring. Population- all the individuals of a single species that live in a specific area.
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2) What was Darwin’s explanation for evolution? https://www.youtube.com/watch?v=KDPLig4lMF o NATURAL SELECTION HOW DOES EVOLUTION REALLY WORK?
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Natural Selection According to Darwin nature controls evolution, the environment selects the characteristics best suited for survival in a particular area.
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3) Geographic Isolation –Physical barriers Bodies of water Lakes Mountains Movie: Elements of biology: agents of evolution The idea that two populations of the same species of organism can evolve separately because of a geographic barrier.
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4) How does Geographic isolation lead to Speciation? Those who have an adaptive variation will survive & reproduce in the different environments. This leads to different species with different variations.
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5) Darwin’s Finches (An Example of Geographic Isolation) All came from a common ancestor & due to different environments on each island, new species evolved that were adapted to their particular environment
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6) Adaptive Radiation Evolution of many species from one common ancestor due to natural selection
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Adaptive Radiation Each group of finches adapted to its new environment, and through the process of natural selection, became different enough that interbreeding became impossible.
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7) Reproductive Isolation: A reproductive barrier keeps similar species from interbreeding. 1)Timing- two similar species may have different breeding seasons. 2)Behavior- two similar species may have different courtship or mating behaviors. https://www.youtube.com/watch?v=bbLpZn4B7b0
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8) How long does evolution take? Evolution takes a long time, but if the environment changes suddenly, evolution will be faster
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Patterns Of Change Species with SHORT reproductive cycles that produce MANY offspring tend to evolve more quickly than species with LONG life spans and FEW offspring. Types: 1)Gradualism – evolution occurs steadily through time (Slow & Continuous). 2)Punctuated Equilibrium- species stay the same for long periods of time and then change rapidly. ------------- ------------------------ No Change
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