The name for the total amount of living matter is biomass. Hopefully this helps :)
A benefit of using nuclear energy could be the abundance of uranium in nature. The human risk about mining that is the most important to consider are the health hazards that are associated with uranium mining.
Genetic drift happens by chance and can make an allele disappear completely from a gene pool, even if it was a desirable trait that should have been passed down to offspring. The random sampling style of genetic drift shrinks the gene pool and therefore alters the frequency the alleles are found in the population.
