natural selection and adaptation lecture Flashcards
is a group of organisms of the same species living together in the same geographic area.
population
Describe the development of antibiotic resistance in terms of evolution by natural selection. How has it occurred
What is the ultimate source of new variation? Does a change in environment cause to new trait to be generated
What is an allele? Use examples in your answer: eye color, AVPR1a variant, shell color
Can you define evolution in under 10 words? Be sure to use the terms “allele frequency” and “gene pool” in your answer to explain how unequal reproductive success leads to evolution in populations
Do individuals evolve? Why or why not
Does environmental challenges result in individual organisms changing to meet those challenges? Does environmental change cause variation to increase or appear in populations? Does the need of an organism to survive cause variation to appear? What happens if there is no trait in a population that would allow survival after an environmental change
. Natural selection is a mechanism of evolution. What is doing the selecting in natural selection
Evolution does not produce “perfect” organisms. Why are adaptations often compromises? (Hint: compare a racehorse with a wild mustang.) Why can’t individuals evolve?
What happens if the variations in a population is insufficient for survival (as can be the case in a period of rapid environmental change)? How are mass extinctions reflected in the fossil record?
Define population, gene pool, gene flow, alleles, evolution, microevolution
Define fitness (as the term is used in evolutionary theory
What are the three main causes of evolutionary change? Natural selection is the primary mechanism by which organisms become adapted to their environment. Contrast the three ways that natural selection can alter allele frequencies in a population: stabilizing, directional, disruptive (aka diversifying) selection
What is a species? Explain the biological species concept. What kinds of situations is it useful for describing, and when it is useless? Why is there not a one-size-fits-all definition of species
Distinguish between microevolution and speciation. What is a reproductive barrier? What does gene flow have to do with reproductive barriers
If given an example, be able to correctly identify if a reproductive barrier is a prezygotic barrier or postzygotic barrier. Give examples of how reproductive barriers might evolve in geographically isolated populations of organisms. Describe the examples of how reproductive barriers might evolve in populations that occur in the same geographical space. Hint: recall the example of the salamanders in California
Distinguish between genetic drift and gene flow. Which increases genetic diversity, and which decreases genetic diversity? Give examples of each. Why are these mechanisms of evolution called ‘nonadaptive
What is Hardy-Weinburg Equilibrium? What five conditions must be met for a population to NOT evolve? It is very unlikely to ever see a natural population that meets all five of these conditions, yet this framework is very useful. Why? Week 8: Speciation Case studies, and intro to Human Evolution
Speciation that occurs when there is a geographical barrier is called allopatric speciation. Populations of a species that are separated by a geographical or physical barrier accumulate different genetic differences while the populations are separated. What are the possible outcomes when the two populations reunite?
Describe the differences between the limnetic sticklebacks and the benthic sticklebacks in Lake Paxton
. Individuals from these two populations of sticklebacks are ablet to successfully reproduce in laboratory conditions, but very few hybrids are found in Lake Paxton. Which option answered in question 1 (above) is likely?
Why is high genetic diversity advantageous to a population of organisms in a changing environment?
What is inbreeding depression? We discussed various examples of inbreeding depression in class (Florida panthers, cheetahs, etc.)
