Some symptoms of a complex kidney cyst include abdominal and flank pain, a palpable growth and hematuria. These symptoms may manifest when a complex renal cyst arises from a simple kidney cyst due to complications or enlargement, notes the Journal of the American Society of Nephrology. Continue Reading.
1 Mutations are changes in the DNA. 2  A single mutation can have a large effect, but in many cases, evolutionary change is based on the accumulation of many mutations. 3  Gene flow is any movement of genes from one population to another and is an important source of genetic variation.ithout genetic variation, some of the basic mechanisms of evolutionary change cannot operate. There are three primary sources of genetic variation, which we will learn more about: 1  Mutations are changes in the DNA.
Genetic variation is an important force in evolution as it allows natural selection to increase or decrease frequency of alleles already in the population. Genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organismâs offspring).