Random fertilization allows random combination of genetic information, which helps synthesize genetically unique gametes. The fusion of a unique sperm together with a unique egg can introduce further variation.
Primary succession is ecological succession that begins in essentially lifeless areas, such as regions in which there is no soil or where the soil is incapable of sustaining life because of recent lava flows, newly formed sand dunes, or rocks left from a retreating glacier.
Created by Rosalind Franklin using a technique called X-ray crystallography, it revealed the helical shape of the DNA molecule. Watson and Crick realized that DNA was made up of two chains of nucleotide pairs that encode the genetic information for all living things.