Answer:
Gene flow is the transfer of genes in and out of a population.
2. Geneflow affect the fitness ofva population.
Gene flow within a population can cause an increase in the genetic variation of the population, whereas gene flow between genetically distant populations can reduce the genetic difference between the populations.
Index fossil is any animal or plant preserved in the rock record of the Earth that is use to identify and gate geologic periods.
Step-by-step explanation:
Gene flow is the transfer of genes or genetic variation in and out of a population.
Gene flow is cause by movement of organisms that reproduce in their new population or movements of gametes. For example, when bees carry pollen from a flower in one location to flowers in another location, the bees are causing gene flow.
Gene flow within a population can cause an increase in the genetic variation of the population, whereas gene flow between genetically distant populations can reduce the genetic difference between the populations. Thereby affecting it's genetic fitness.
Index fossil is any animal or plant preserved in the rock record of the Earth that is use to identify and gate geologic periods. Examples of index fossils include: Ammonites were common during the Mesozoic Era (245 to 65 mya