AP BIOLOGY

Detailed explanation-1: -Individuals produce more offspring than their environment can support, and some die because of factors such as predation, food shortage or disease. These factors are known as environmental selection pressures and they determine which individuals will do best at surviving and reproducing.

Detailed explanation-2: -Changes in environmental conditions can lead to shifts in selective pressures. Thus, new mutations may be advantageous or previous favorable ones may become deleterious [1, 2]. Diseases caused by deleterious mutations are not expected to persist for many generations or to segregate at high frequency.

Detailed explanation-3: -Selection pressures are factors that exist in an environment that make it easier for some organisms to survive and others less likely to survive.