lecture 12 - natural selection

Question 1

do infections diseases impact the human genome? ex?

Answer 1

• Infectious diseases impacting the human genome?
  ○ Yes, many examples of this such ad TB, and small pox
  ○ Historical migration out of africa- Encountering infectious diseases
  ○ Natural selection happening during thistime frame
  ○ Evidence that our own genome impacts whether we get sick of these diseases or not
  ○ Infectious diseases play a role in shaping our genome + making us fit (selection)

Question 2

define fitness

Answer 2

• Not physical fitness
  
  • Fitness: the probability of survival and reproduction

Question 3

define absolute fitness

Answer 3

Absolute fitness: a measurement of fitness comparing the actual number of individuals by genotype at two different times, such as generation to generation, or birth and adulthood
Avg number of offspring of a given type per parents of the given type. One can speak of the fitness of an individual/genotype/allele

Question 4

define relative fitness. is it used often?

Answer 4

• Relative fitness: a measurement of fitness once the genotype is assigned a value of 1.0 and the fitness Values of other genotypes are defined relative to that genotype
  ○ Used more often than absolute fitness
  Avg. contribution of the offspring generation relative to the contribution of another type

Question 5

when is natural selection occuring if given expected vs real pop numbers

Answer 5

Natural selection occurs if one value is different