Born December 21, in Melrose, Massachusetts, to Philip Green Wright and Elizabeth Quincy Sewall Wright. Moved to Galesburg, Illinois, where his father taught at Lombard College.

Genetic drift describes random fluctuations in the numbers of gene variants in a population. Genetic drift takes place when the occurrence of variant forms of a gene, called alleles, increases and decreases by chance over time. These variations in the presence of alleles are measured as changes in allele frequencies.

Genetic drift, also called genetic sampling error or Sewall Wright effect, a change in the gene pool of a small population that takes place strictly by chance.

Mutation is important as the first step of evolution because it creates a new DNA sequence for a particular gene, creating a new allele. Recombination also can create a new DNA sequence (a new allele) for a specific gene through intragenic recombination.

A mutation is a change in DNA, the hereditary material of life. So a change in an organism’s DNA can cause changes in all aspects of its life. Mutations are essential to evolution; they are the raw material of genetic variation. Without mutation, evolution could not occur.

Point mutations are a large category of mutations that describe a change in single nucleotide of DNA, such that that nucleotide is switched for another nucleotide, or that nucleotide is deleted, or a single nucleotide is inserted into the DNA that causes that DNA to be different from the normal or wild type gene …

There are two types of point mutations: transition mutations and transversion mutations.

Most proteins can withstand one or two point mutations before their function changes. For example, sickle-cell disease is caused by a single point mutation (a missense mutation) in the beta-hemoglobin gene that converts a GAG codon into GUG, which encodes the amino acid valine rather than glutamic acid.

Deletions are responsible for an array of genetic disorders, including some cases of male infertility, two thirds of cases of Duchenne muscular dystrophy, and two thirds of cases of cystic fibrosis (those caused by ΔF508).

Although inversions often don’t have any observable effect on the carrier, they can lead to an increased risk of abnormal offspring.

Hemophilia A, a genetic bleeding disorder, is often caused by chromosomal inversions that involve a portion of the blood coagulation factor VIII (F8) gene that encodes one of the key enzymes in blood clotting.

Genetic disorders

• Albinism. Albinism is a group of genetic conditions.
• Angelman syndrome. A rare syndrome causing physical and intellectual disability.
• Ankylosing spondylitis.
• Apert syndrome.
• Charcot-Marie-Tooth disease.
• Congenital adrenal hyperplasia.
• Cystic fibrosis (CF)
• Down syndrome.