Paleontologist observed changes in the sizes of black bears as an environment changed during warmer periods between ice ages. Most black bears were small during ice ages most black bears were large which type of selection is this and how would the graph of the distribution curve a black bear size change, as the earth moved out of the ice age?
The type of selection observed in this scenario is called directional selection. This is because there is a consistent shift in the average size of black bears over time due to changes in the environment.
During ice ages, where the environment is colder, smaller black bears are favored as they have a better chance of surviving and reproducing in these conditions. On the other hand, during warmer periods between ice ages, larger black bears are favored as they are better adapted to the new environment.
If we were to graph the distribution curve of black bear size as the earth moved out of the ice age, we would expect to see a shift towards larger sizes. Initially, the curve would be skewed towards smaller sizes, representing the prevalence of smaller black bears during the ice age. However, as the environment becomes warmer, larger black bears would have a higher fitness and survival rate, causing the curve to shift towards larger sizes.