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.
Variation is high when there are many different alleles of all genes and when there are many different combinations of those alleles. However, genetic variation is constantly changing. Different alleles of a single gene can appear and disappear from time to time within a group.ecombination (Crossing Over). This is the exchange of genetic material between adjacent chromatids on the homologous chromosomes. This random exchange of DNA results in many new combinations of alleles on chromosomes, creating great potential for variation.