Answer:
Hello! The correct answer should be "<u>Excess phosphorus from the runoff of fertilizer and animal waste that ends up in ponds."</u>
Explanation:
An algal bloom is mostly caused by the presence of large amounts of nitrogen and phosphorus present in water. These nutrients are washed away from lands and farms that are heavily riddled with nitrogenous and phosphatic fertilizers.
Rain acts as an agent by washing these leachable nutrients from the soil into water bodies such as rivers and streams, which eventually end up in large reservoirs such as lakes and oceans.
These nutrients are also deposited into waterways through drainage systems. Due to poor sewage treatment, untreated raw sewage finds its ways into water bodies, and because it is rich in nitrogen compounds such as nitrates and ammonia, it causes algal bloom.
Water pollution, particularly the discharge of poorly treated or untreated industrial waste into waterways, leads to the release of raw toxic waste into water systems. Since it contains nutrients and compounds such as nitrogen, lead, and phosphorus, the outcome is the dense growth of algae.
Answer:
The evolutionary mechanism that could be influencing the allele frequencies between both islands and the mainland population might be Founder Effect.
Explanation:
Genetic drift is the random change that occurs in the allelic frequency of a population through generations. The magnitude of this change is inversely related to the size of the original population. These changes produced by genetic drift accumulate in time and eventually, some alleles get lost, while some others might set. Genetic drift affects a population and reduces its size dramatically due to a disaster -bottleneck effect- or because of a population split -founder effect-. In <u>founder effect</u>, a new population originates when a few individuals who are coming from a bigger population carrying its genes, settle down in a new area and reproduce. This small population might or might not be genetically representative of the original one. Some rare alleles might be exceeded or might be completely lost. Consequently, when the small population increases in size, it will have a genetically different composition from the original one. In these situations, <u>genetic variability is reduced</u> and there exists the possibility of developing a peculiar allelic composition. If the number of individuals that originated the new population is low, the founder effect will be very extreme, because the effects of the genetic drift are inversely proportional to the original number of individuals.
<em>In the exposed situation, the evolutionary mechanism that could be influencing the allele frequencies between both islands and the mainland population might be Founder Effect. The fact that both islands are similar in their frequencies might be due to little genetic variation on island 1, or because dispersion to island 2 is a recent event on time. </em>
The amount of water on the planet is fixed; it neither increases or decreases. Glaciers are sheets of moving ice. This water to form these extensive sheets must come from somewhere. The water comes from the most extensive store on the planet; the oceans. Ice Ages always corresponds to periods of low sea level because much of the ocean water is is land locked as glaciers.
