- Based on your first simulation - the beanus (prey) population started with an equal number of individuals of each variation. Over the course of the experiment:
- Which variation(s) became more common in the total population? Explain why.
The fork cannot pick up the small, flat lentils, so this variation became more common.
- Which variation(s) became less common in the total population or were eliminated? Explain why.
Garbanzos are large and round, and easily picked up; they became less common.
- Did any variation remain about the same in the total population? Explain why.
Pintos are intermediate in phenotype; their population size should be between the other two beanus variations.
- Based on your second simulation - the beanus (prey) population again started with an equal number of individuals of each variation. Over the course of the experiment:
- Which variation(s) became more common in the total population? Explain why.
The knife cannot pick up the round garbanzos, so this variation became more common.
- Which variation(s) became less common in the total population or were eliminated? Explain why.
Lentils are flat and easily picked up; they became less common.
- Did any variation remain about the same in the total population? Explain why.
Pintos are intermediate in phenotype; their population size should be between the other two beanus variations.
- What is meant by "survival of the fitter" and why is it more appropriate to say "survival of the fitter" rather than "survival of the fittest"? Explain how this concept is demonstrated in this lab.
Fitness depends on the environment, including predators, so there is no "fittest" for all situations.
- Extrapolate the results of your simulation(s) to natural predator and prey populations.
- Explain how natural predator and prey populations adapt in response to each other (i.e. how the predator-prey interaction acts as the selection agent). Provide an example from natural predator and prey populations as part of your discussion.
Prey adapt to predator by becoming harder to catch.
Predator adapt to prey by becoming more efficient at catching prey.
Examples of this "evolutionary arms race" are birds catching beetles, cheetah chasing gazelles, foxes hunting rodents.
- What is this particular evolutionary pattern called?
Adaptation; also co-evolution, evolutionary arms race.
- Aside from biotic factors such as predator-prey interactions, abiotic factors also operate as selection agents on species. Identify two abiotic factors and provide examples from natural populations to illustrate how these factors have operated as agents of natural selection.
Climate (saguaro), tides (barnacles), bark color (beetles).
- Humans as a biotic component of the ecosphere have acted in many ways to directly or indirectly function as a selection agent for other species. Describe two specific examples of how human activities have operated as agents of selection on plant and animal species.
Use of insecticides select for pesticide-resistant variations.
Use of antibiotics select for drug-resistant bacteria.
Artificial selection of domesticated pets, crops, pigeons
