Which of these is most probable when a sudden environmental shift applies pressure to a few generations of a population? A. Decreased mutation rates in population members B. Increased genetic variation in the population C. Evolution of a new organism population D. Differences in population members survival rates

## Step 1<br />This problem is about the concept of natural selection and evolution. When a sudden environmental shift applies pressure to a population, it can lead to changes in the population's genetic makeup over generations. This is because certain traits may become more or less common in the population due to the selective pressure of the environment.<br /><br />## Step 2<br />Option A, decreased mutation rates in population members, is not necessarily a direct result of environmental pressure. Mutations occur randomly and are not directly influenced by environmental changes.<br /><br />## Step 3<br />Option B, increased genetic variation in the population, can be a result of environmental pressure. However, this is not the most probable outcome. Genetic variation can increase due to mutations, but environmental pressure alone does not increase genetic variation.<br /><br />## Step 4<br />Option C, evolution of a new organism population, is a long-term process that involves many generations and is not a direct result of a sudden environmental shift.<br /><br />## Step 5<br />Option D, differences in population members' survival rates, is the most probable outcome when a sudden environmental shift applies pressure to a population. This is because the environment can favor certain traits over others, leading to differential survival rates.