Answer:
The population of juncos at the University of California, San Diego (UCSD) campus has become bolder than the mountain population over the last 60 years, and this change can be explained by the process of natural selection.
Juncos are small, sparrow-like birds that are found in a variety of habitats across North America. The UCSD campus population and the mountain population of juncos are two distinct groups that have evolved separately over time.
One important factor that drives the process of natural selection is the availability of resources, such as food and shelter. On the UCSD campus, the juncos have access to a variety of resources provided by humans, such as bird feeders and landscaped gardens. These resources allow the juncos to survive and reproduce more successfully than they might in the wild, leading to an increase in the population size.
As the population size increases, there is more competition for resources, and only the boldest individuals can access them. Over time, bolder individuals are more likely to survive and reproduce, passing on their genes for boldness to the next generation. As a result, the overall population becomes bolder over time.
In contrast, the mountain population of juncos likely has fewer resources available and faces more challenges in finding food and shelter. As a result, the selection pressure for boldness is likely to be weaker in this population, leading to less of a change in the overall level of boldness.
Therefore, the difference in the level of boldness between the UCSD campus population and the mountain population can be explained by the process of natural selection, which has favored bolder individuals in the campus population due to the availability of resources provided by humans.
Step-by-step explanation: