Question

Researchers designed an experiment to test the hypothesis that the evolution of coloration in lice is driven by birds. researchers transferred 25 lice from a random sample of lice obtained from wild‑caught rock pigeons to each individual in groups of black pigeons and white pigeons. half of the pigeons from each color group were fitted with a harmless mouthpiece that stopped the beaks from entirely closing. the mouthpiece prevented pigeons from removing lice but did not affect the pigeons’ ability to feed. each pigeon was isolated and kept in identical environmental conditions for temperature, humidity, and amount of light. the lice have a generation time of 24 days. the researchers observed the phenotypes of the lice over a period of four years.

Answer 1

Predator-induced selection pressure can lead to directional selection in prey species, influencing evolutionary outcomes such as coloration. Experiments with animals like birds and butterflies show how predators' responses can affect prey phenotype frequencies over time, supporting the theory of natural selection.

Step-by-step explanation:

The concept of natural selection and predation pressure in the context of the evolution of species' coloration is a fundamental aspect of biology. When predator species respond differently to varying colorations of their prey, they can exert a selective pressure, influencing the directional selection towards favorable phenotypes. Empirical experiments, like the one with the yellow buntings and butterflies, offer evidence supporting this concept. If buntings display fleeing behavior less frequently towards butterflies with eyespots, this could suggest a selective advantage for butterflies with eyespots in naturally avoiding predation.

Directional selection is demonstrated in classic examples such as the peppered moth, where environmental changes like the pollution from the Industrial Revolution led to a shift in moth coloration from light to dark; this allowed the darker moths to better camouflage against soot-covered trees, thus evading predation and surviving to pass on their genes. Similar principles can be applied to understand how coloration in lice might evolve in response to the color of their avian hosts and the host's ability to preen and remove lice using their beak.