Dominant' traits will actually disappear faster if they are disadvantageous.
Think about it: if everyone who has even a single copy of a particular allele is at a disadvantage (manifests the phenotype, in this case six fingers), then even single copies are selected against.
In the case of recessive traits, selection occurs only against homozygous carriers, who may be very rare if the allele itself is rare.
A concrete example would be something like Tay-Sachs disease. If the allele that causes this were dominant, every carrier would die before adulthood, and it would occur only as a very rare de novo mutation. But because it is recessive, it persists for now; heterozygous carriers have no disadvantage.
A dense growth of plant life in a aquatic ecosystem which many animals living there die(due to lack of enough oxygen present in water) and the ecosystem gets completely disrupted.
Eutrophication excessive richness of nutrients in a lake or other body of water, frequently due to run-off from the land, which causes a dense growth of plant life.
Answer:
A. increase in American pika population size
Explanation:
Carrying capacity is the idea that relates to how much population can an environment sustain before collapsing. Here, the answer would be A. increase in American pika population size because if you increase the food for weasals, naturally the population carrying capacity goes up because now the environment has food to feed the weasals which can contribute to increasing the carrying capacity (i.e. the environment can now handle larger population of weasel than initial condition)
