However, not all pension plans allow such withdrawals. Many pension plan rules do not allow in-service distributions, or withdrawals while you are still in service with the company. Some defined benefit pension plans do not allow early distributions at all. Others, such as some 401k plans, allow workers to make withdrawals at any time.
These indices not only measure species richness, but also take into account the relative abundance of species, or evenness. When measuring species diversity, species richness and evenness must always both be considered. In addition, indices provide important information about species rarity and commonness in a population. These are important and common tools used by biologists in order to understand community structure.
The interdependence between genetic and species diversity is delicate. Changes in species diversity lead to changes in the environment, leading to adaptation of the remaining species. Changes in genetic diversity, such as in loss of species, leads to a loss of biological diversity.enetic diversity serves as a way for populations to adapt to changing environments. With more variation, it is more likely that some individuals in a population will possess variations of alleles that are suited for the environment. Those individuals are more likely to survive to produce offspring bearing that allele.