05 ch22evolutiontests2008

05 ch22evolutiontests2008

• 1.
  Evidence of Evolution by Natural Selection Testable Hypotheses AP Biology 2007-2008
• 2.
  Peppered Moths  Dark vs. light variants Year % dark % light 1848 5 95 1895 98 2 1995 19 81 AP Biology
• 3.
  Peppered moth  What was the selection factor?  early 1800s = pre-industrial England  low pollution  lichen growing on trees = light colored bark  late 1800s = industrial England  factories = soot coated trees  killed lichen = dark colored bark  mid 1900s = pollution controls  clean air laws  return of lichen = light colored bark  AP Biology industrial melanism
• 4.
  Natural selection inaction  Insecticide & drug resistance  insecticide didn’t kill all individuals  resistant survivors reproduce  resistance is inherited  more of population is resistant  insecticide becomes less & less effective AP Biology
• 5.
  Genome sequencing  What can data from whole genome sequencing tell us about evolution of humans? AP Biology
• 6.
  Primate Common Ancestry? Chromosome Number in the Great Apes (Hominidae) orangutan (Pogo) 48 gorilla (Gorilla) 48 chimpanzee (Pan) 48 human (Homo) 46 Could we have Hypothesis: Hypothesis: just lost a pair of Change in chromosome number? Change in chromosome number? chromosomes? If these organisms share a common If these organisms share a common ancestor, then is there evidence in ancestor, then is there evidence in the genome for this change in the genome for this change in chromosome number AP Biology chromosome number
• 7.
  Chromosomal fusion Testable prediction: Testable prediction: If common ancestor had 48 chromosomes (24 pairs), If common ancestor had 48 chromosomes (24 pairs), then humans carry a fused chromosome (23 pairs). then humans carry a fused chromosome (23 pairs). Ancestral Chromosomes Fusion Homo sapiens Chromosome Number in the Great Apes Inactivated centromere (Hominidae) Telomere sequences orangutan (Pogo) 48 gorilla (Gorilla) 48 chimpanzee (Pan) 48 Testable! human (Homo) is what makes This 46 evolution science Centromere AP Biology & not belief! Telomere
• 8.
  Hillier et al(2005) “Generation and Annotation of the DNA sequences of human chromosomes 2 and 4,” Nature 434: 724 – 731. Test of the Human Genome Ancestral “Chromosome 2 is unique to the human Chromosomes Fusion Homo sapiens “Chromosome 2 is unique to the human lineage of evolution, having emerged as a lineage of evolution, having emerged as a result of head-to-head fusion of two result of head-to-head fusion of two chromosomes that remained separate in Inactivated chromosomes that remained separate in other primates. The precise fusion site has centromere other primates. The precise fusion site has been located in 2q13–2q14.1, where our been located in 2q13–2q14.1, where our Telomere analysis confirmed the presence of multiple analysis confirmed the presence of multiple sequences subtelomeric duplications to chromosomes subtelomeric duplications to chromosomes 1, 5, 8, 9, 10, 12, 19, 21 and 22. During the 1, 5, 8, 9, 10, 12, 19, 21 and 22. During the formation of human chromosome 2, one of formation of human chromosome 2, one of the two centromeres became inactivated the two centromeres became inactivated (2q21, which corresponds to the centromere Well I’ll (2q21, which corresponds to the centromere from chimp chromosome 13) and the centromeric a monkey’s Chr 2 be structure quickly deterioriated.” from chimp chromosome 13) and the …or an ape’s… centromeric structure quickly deterioriated.” uncle! Human Chromosome #2 shows the exact Human Chromosome #2 shows the exact point at which this fusion took place point at which this fusion took place AP Biology
• 9.
  In case youhad any doubts…
• 10.
  Any Questions?? AP Biology 2007-2008