CH 13: How Populations Evolve: microevolution: changes in gene allele.frequencies.(Printer)
                                                    macroevolution: the fossil record, in this & many later Ch
                                                    evolution: all topics
DNA is used to study both macroevolution (lab ex 8), & microevolution
Resources: wiki,  Evolution course: click circle logo: & teaching,

1. BOX: Persistent Pests = microevolution, fig 1 is ON LEFT,
          on Right: organic farming reduces development of pesticide resistance!!!!
  1. Pesticide-resistant insect populations evolve by artificial selection.
  2. rising cost of growing cotton (partly due to inflation), pests = all not wanted: animals, plants, fungi etc.,
  3. GMO food will cause resistance in pests
  4. antibiotic resistance, MRSA, C. difficle,
  5. Resistance is slow to develop as bacteria are haploid = mostly clones
  6. HIV resistance to drugs,  human resistance to HIV,  more recent
  7. Evolution underlies both the unity & diversity of life on earth  title of biology textbook.
  8. Unity: DNA > RNA > protein, all organisms use same genetic code,
  9. & molecules, organelles, cells, tissues, organs etc are similar
  10. Diversity: see next section (& next Ch), despite basic unity life is very diverse
    11. 9. Natural or artificial selection: Dogs, More Dogs, evolved from wolves but how?
    selection mechanism: dogs may have domesticated themseleves by putting up with early humans
    Wolf Park, wiki: dogs, Domestication in general i.e. artificial selection
2. Charles Darwin and The Origin of Species  fig 2
Darwin had no idea about the above mechanisms for microevolution, but he realized they must exist.
His accomplishment required an enormous act of faith! Down House, Darwin Library in NY, 

The idea of fixed species began with the Greeks, & reinforced in Judeo-Christian beliefs.
1700s: Buffon studied fossils & mathematics, suggested maybe world is older than 6,000 years 
1800s Lamarck suggested inheritance of acquired characteristics WRONG!
Darwin's voyages on the Beagle (1831)
Darwin saw & collected: many new organisms, distinctly South American,  marine iguana
Darwin also saw variations = adaptations: Darwin's finches:  = fig 14

Lyell developed geology concepts - gave evidence that the Earth was old, carved by erosion,
rose up: scroll to Charmouth fossils,  golden cap, to form mountains, (plate tectonics came later)

Wallace pressured 1858 Darwin: he had the same idea: 1859: on The Origin of Species
Darwin's two main points:
1) Life has descended from ancestral species - descent with modification = like fig 5
(Field museum display: hoofed mammals evolved more than once: A here)
2) Natural selection makes this happen - survival of the fittest (CAREFUL what you click!)

Checkpoint p 249
1. What is gradualism?  Did Darwin approve?  Now considered more likely is punctuated equilibrium
2. Darwin's two main points? (above)
3. Darwin's phrases: 1)  ?   with   ?,  & 2) the accumulation of ? to various environments: fig 5a & b

Evidence of Evolution = what convinced Darwin
    1) the fossil record, fig 6; fig 9: more of them are missing links,
    2) biogeography - east asia - organisms in isolated locations are more similar:  S. America above
        Australia's marsupials, mammals elswhere = fig 10, evolution
    3) comparative anatomy, fig 11: adaptations, but same bones, jaws from gill arch, our fishy ancestry
    4) comparative embryology, fig 12, - all vertebrates have fishy early embryo = descent with modification
            each embryo stage adapts as needed, BUT...    Wiki  more on this
        5) molecular biology, fig 12:  species differences in DNA: accumulate over time,
            all primates nearest living relative
Checkpoint p 253
1. Why are fossils in deeper SEDIMENTARY rock layers older than fossils in younger rock layers?  rock cycle
Always true?: fold vs block,
2. What is homology & analogy

3. Natural Selection and Adaptive Evolution
  1. Darwin's two main observations that led to the concept of natural selection:
  2. 1) overproduction, 2) individual variation
  3. lead to inference: differential reproductive success: not all survive & reproduce = Darwinism
  4. Natural selection is more a process of editing
  5. Creative mechanisms are sexual reproduction & mutation.
HALF WAY P 256 CHECKPOINTS
1. Define Natural Selection
2. T/F? Pesticides cause pesticide resistance

4. The Modern Synthesis: Darwinism + Mechanism: Population Genetics, 
  1. The modern synthesis integrates Darwin's ideas & the concepts of population genetics,
  2. (More independent evidence came with understanding: DNA gene > RNA > Protein)
  3. Population genetics: how the frequencies/proportions of the alleles of a gene change over time
  4. A population of a species living in a given geographic area is the smallest unit of evolution.

  6. Genetic variation: there is only one human population
    7. Prokaryotes: variation is from mutation, as reproduction is mostly asexual = clone (but rapid),
  7. Eukaryotes: generation time is long: sexual recombination is the primary mechanism of evolution
           Analyzing Gene Pools
         The Hardy-Weinberg formula determines the frequency of genotypes in a gene pool:
    Gene has 2 alleles: A & a, so genotypes are: AA, Aa & aa. 
    Let the proportion/frequency of A = p, & of a = q, so p + q = 1
                                        then (p+q)*(p+q) = p2 + 2pq + q2 = 1 = H-W formula
    In a population, the proportion/frequency of:  AA = p2, Aa = 2pq, & aa = q2, fig 20.
     
  1. The H-W formula for genetic equilibrium has these assumptions.

    2. Population Genetics & Health Science
H-W calculator: the average lethal recessive disease: kills 1/10,000 births (aa), has 1/50 carriers (Aa)! 
    If the frequency of aa is 1/10,000 & the person dies,
    then this is 1/2 the frequency that the bad mutation occurs, to replace the two lost
    Human genetics course, last part is evolution mechanisms (below)

    Microevolution = change in a population's gene pool = change in allele frequencies

    Checkpoint p 260
    1. what is the smallest unit that can evolve?
    2. define microevolution
    3. which term in p2 + 2pq + q2 = 1 represents individuals with no allele for the disease?
    4. in humans does mutation or sexual recombination produce most variation?
5. Mechanisms of Microevolution Wiki's five adds artificial selection (discussed already)
         same as textbook four: 1. genetic drift, 2. gene flow, 3. mutation, & 4. natural selection
           Four: quantifies mechanisms, & sorts as new variants vs biased transmission
  1. 1. Genetic drift: fig 22-25: only in small population, chance: an allele is lost or fixed (100%).
  2. mechanism includes: founder effect, fig, PBS, bottleneck effect: fig 23, fig 24.
  3. flexible simulation, too clever

  5. 2. Gene flow: immigration: (Lab Ex 10) allele(s) added to population from another population

  7. 3. Mutation: discussed already
          4. Natural Selection a Closer Look simulation..(evolution lab, takes time to figure out).
  1. 3) Directional, 2) diversifying/disruptive, & 1) stabilizing selection: fig 28, 
    2. same: last part of page. easier to see if process continues, human fig.,which?, finches,
    peppered moth turned black during industrial revolution/coal, wiki/scroll,
  2. Darwinian fitness
  3. H-W simulation + fitness, so p & q change
  4. Review microevolution resource
Checkpoint p 265
1. Compare bottleneck effect & founder effect as causes of genetic drift
2. Why does a new disease pose a greater threat to cheetahs than humans?
3. Which mechanisms of microevolution have been most affected by increasing human travel?
4. What is the best measure of Darwinian fitness?
5. As the climate gets colder! bear fur thickness increases over generations,
    is this directional, stabilizing or disruptive selection?
6. Is antibiotic resistance natural or artificial selection?

6. Evolution Connection: Population Genetics of the Sickle-Cell Allele
  1. Sickle-cell anemia is more common in African Americans than others,
    2. fig 29, map: stabilizing selection: Aa is favoured where disease occurs,
Large Resource, most topics & many links: Evolution for biology Students