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Regents Biology 2006-2007 Witness to Evolution
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Regents Biology Witness to Evolution Peppered Moth 2 types: dark vs. light Peppered moth light
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Regents Biology Peppered moth: Evolution in action Year% dark% light 1848 595 1895 982 1995 19 81 clean air, light-colored bark pollution, dark-colored bark Clean Air Act, light-colored bark industrial melanism
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Regents Biology Peppered moth Why did the population change? early 1800s = pre-industrial England low pollution lichen on trees = light colored bark late 1800s = industrial factories = soot coated trees killed lichen = dark colored bark mid 1900s = pollution controls clean air laws return of lichen = light colored bark
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Regents Biology What data from the Genome Project can tell us about evolution of humans
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Regents Biology Chromosome Numbers in the great apes: 46 human (Homo)46 chimpanzee (Pan)48 gorilla (Gorilla)48 orangutan (Pogo)48 Chromosome Numbers in the great apes: 46 human (Homo)46 chimpanzee (Pan)48 gorilla (Gorilla)48 orangutan (Pogo)48 Change in chromosome number? If these organisms share a common ancestor, then is there evidence in the genome for this change in chromosome number Change in chromosome number? If these organisms share a common ancestor, then is there evidence in the genome for this change in chromosome number
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Regents Biology Chromosome Numbers in the great apes (Hominidae): human (Homo)46 chimpanzee (Pan)48 gorilla (Gorilla)48 orangutan (Pogo)48 Testable prediction: Testable prediction: If common ancestor had 48 chromosomes (24 pairs) then humans carry a fused chromosome; or If common ancestor had 46 chromosomes (23 pairs) then apes carry a split chromosome. Centromere Telomere Ancestral Chromosomes Fusion Homo sapiens Inactivated centromere Telomere sequences
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Regents Biology “Chromosome 2 is unique to the human lineage of evolution, having emerged as a result of head-to- head fusion of two acrocentric chromosomes that remained separate in other primates. The precise fusion site has been located in 2q13–2q14.1 (ref. 2; hg 16:114455823 – 114455838), where our analysis confirmed the presence of multiple subtelomeric duplications to chromosomes 1, 5, 8, 9, 10, 12, 19, 21 and 22 (Fig. 3; Supplementary Fig. 3a, region A). During the formation of human chromosome 2, one of the two centromeres became inactivated (2q21, which corresponds to the centromere from chimp chromosome 13) and the centromeric structure quickly deterioriated (42).” Homo sapiens Inactivated centromere Telomere sequences Hillier et al (2005) “Generation and Annotation of the DNA sequences of human chromosomes 2 and 4,” Nature 434: 724 – 731. Human Chromosome #2 shows the exact point at which this fusion took place Chr 2
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Regents Biology In case you had any doubts… In case you had any doubts…
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Regents Biology 2006-2007 Evolution is "so overwhelmingly established that it has become irrational to call it a theory." -- Ernst Mayr What Evolution Is 2001 Professor Emeritus, Evolutionary Biology Harvard University (1904-2005)
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Regents Biology Survival of the Fittest
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