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Zool 141 Final
1 The fact that women often seek mates who are taller
2. Certain individuals contribute disproportionately to the next generation. For example, breeding cows
with valuable characteristics (high milk production) form one bull could be compared to the one man
having more than one child with various women
3. the high frequency of albino amon Arizona Hopi Indians is another example.
Genetic drift occurs when a small group is seperated from a larger population. The founder effect occurs
when small groups of people leave their homes (Native Americans in North America) to find a new
settlement. The new colony may have different geno type frequencies than the original population and
apply rare traits ie Type B blood in the NA Indian.
The founder effect can also increase the proportion of an allele in a population. 2.5 million Afrikaners, for
example, desended form the Dutch, French, German immigrants. These immagrants would have 10 kids,
some of the Afikaner population migrated / lived in issolation, and developed porphyria varigta which is
dominately inherited enzyme defect whose only sympton is noticed when barbitrate anesthetics are
introduced (later in history).
Founder-small groups move and exploit bad gene
Bottlenect-inbreeding brings out (expresses) recessive genes
1. Founder effect- The smaller groups left behind would exemplify the bad genes
2. Founder effect-The 10 people are part of the population of 100 that would finally settle in the
3. Bottleneck, people trapped on an island (Okinawa, etc) will mate with their cousins, brothers,
etc and cause inbreeding to bring out the bad genes.
TB illustrates natural selection or better known as the survival of the fittest. A bacteria and human
populations may have been responsible for the initial decline. Some people were just less susesptable and
the antibiotics killed the rest. By the 80ís, however, when antibiotics were used to slow the symptoms, but
not completely taken to kill the bacteria. This made the surviving bacteria stronger, and tougher, and the
population weak. The disease spreads by sneezing!
Fig 13.5 The amino acid sequence are a measure of evolutionary relatednedd. For example, similarities
between chimp and human resp protein (Cytachrone C) is exactly the same antidivreetic hormone peptide is
8 amino acids long and only differs slightly between major groups of vertebrates.
1. Foreign antigens (flu) enter the body
2Macrophage engufs and breaks down the foreign antigen
3. HLA Self antigen activates a T cell to stimulate other aspects of the immune response
4. TCells stimulate B cells
5. B Cells proliferate the macrophages (stage 2) secretes interleukin-1, stimulates the T cell to replicate and
causes a fever which may slow viral replication.
At 18 months of life, a fetus does not have its own immune system (active immunity) A "pregnancy block"
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Immune system, Medicine, Biology, Immunology, Bacteria, Adaptive immune system, Evolution, Immune tolerance, Macrophage, Tumor antigens recognized by T lymphocytes
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