2006-2007 Regents Biology

Witness to Evolution

Regents Biology

Witness to Evolution Peppered Moth

2 types: dark vs. light

Peppered moth

light

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Peppered moth: Evolution in actionYear % dark % light1848 5 951895 98 21995 19 81

clean air, light-colored bark

pollution, dark-colored bark

Clean Air Act, light-colored bark

industrial melanism

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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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What data from the Genome Project can tell us about evolution of humans

What data from the Genome Project can tell us about evolution of humans

Regents Biology

Chromosome Numbers in the great apes:

human (Homo) 4646chimpanzee (Pan) 48gorilla (Gorilla) 48orangutan (Pogo) 48

Chromosome Numbers in the great apes:

human (Homo) 4646chimpanzee (Pan) 48gorilla (Gorilla) 48orangutan (Pogo) 48

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

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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Chromosome Numbers in the great apes (Hominidae):

human (Homo) 46chimpanzee (Pan) 48gorilla (Gorilla) 48orangutan (Pogo) 48

Testable prediction:Testable prediction: If common ancestor had 48 chromosomes (24 pairs) then humans carry a fused chromosome; orIf common ancestor had 46 chromosomes (23 pairs) then apes carry a split chromosome.

Centromere

Telomere

Ancestral Chromosomes

FusionHomo sapiens

Inactivated centromere

Telomere sequences

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“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).”

“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.

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

Human Chromosome #2 shows the exact point at which this fusion took place

Chr 2

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In case you had any doubts…In case you had any doubts…

2006-2007 Regents Biology

Evolution is "so overwhelmingly established that it has become irrational to call it a theory."

-- Ernst Mayr What Evolution Is

2001Professor Emeritus, Evolutionary Biology

Harvard University

(1904-2005)

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Survival of the Fittest