Population density = total number of individuals divided by land area
land area should be expressed in square kilometers
thus, 120 ha = 120 x 0.01 = 1.2 square kilometers since 1 ha = 0.01 square kilometers
total population= (80 x 1500)/100 = 1200
so, the population density is 1200/1.2 = 1000
Answer:
1. Mutation- enhances genetic variation
2. Selection- may raise, lower, or maintain genetic variation
3. Genetic drift- diminishes genetic variation.
4. Gene flow- could either enhance or reduce genetic variation
Explanation:
1. Mutation denotes changes in an organism's DNA. The mutations lead to new adaptive traits that evolve, which increases the genetic diversity of organisms.
2. Natural selection favors organisms best suited to their environment. Thus, selection can increase, decrease, or keep variation in a population steady.
3. Genetic drift occurs due to random events altering a population's gene pool. When this phenomenon transpires, the genetic variation within that population typically decreases.
4. Gene flow involves changes to the gene pool due to immigration and emigration. This factor can thus increase or decrease genetic variation.
Becher suggested that the combustion of a material stems from a substance known as phlogiston.
