Inbreeding

Inbreeding is the sexual reproduction of offspring from the mating or breeding of individuals or organisms that are closely related genetically. By analogy, the term is used in human reproduction, but more commonly refers to the genetic disorders and other consequences that may arise from incestuous sexual relationships and consanguinity.

Inbreeding results in homozygosity, which can increase the chances of offspring being affected by recessive or deleterious traits. This generally leads to a decreased biological fitness of a population (called inbreeding depression), which is its ability to survive and reproduce. An individual who inherits such deleterious traits is referred to as inbred. The avoidance of such deleterious recessive alleles caused by inbreeding, via inbreeding avoidance mechanisms, is the main selective reason for outcrossing. Crossbreeding between populations also often has positive effects on fitness-related traits.

Inbreeding is a technique used in selective breeding. In livestock breeding, breeders may use inbreeding when, for example, trying to establish a new and desirable trait in the stock, but will need to watch for undesirable characteristics in offspring, which can then be eliminated through further selective breeding or culling. Inbreeding is used to reveal deleterious recessive alleles, which can then be eliminated through assortative breeding or through culling. In plant breeding, inbred lines are used as stocks for the creation of hybrid lines to make use of the effects of heterosis. Inbreeding in plants also occurs naturally in the form of self-pollination.

Johnny Knoxville

Johnny Knoxville (born Philip John Clapp, Jr.; March 11, 1971), is an American actor, comedian, film producer, screenwriter, and stunt performer. He is best known as a co-creator and star of the MTV reality stunt show Jackass, which aired for three seasons from 2000–2002. A year later, Knoxville and his co-stars returned for the first installment in the Jackass film series, with a second and third installment being released in 2006 and 2010, respectively. In 2013, he starred in Jackass Presents: Bad Grandpa as his Jackass character Irving Zisman. Knoxville has had acting roles in films like Men in Black II (2002), The Dukes of Hazzard, The Ringer (both 2005) and The Last Stand (2013), as well as having voiced Leonardo in Teenage Mutant Ninja Turtles (2014).

Early life

Knoxville was born Philip John Clapp, Jr. in Knoxville, Tennessee. His father, Philip Clapp, Sr., was a tire/car salesman, and his mother, Lemoyne Clapp (née Houck), taught Sunday school. Knoxville credits a copy of Jack Kerouac's On the Road, given to him by his cousin, singer-songwriter Roger Alan Wade, with giving him the acting bug. After graduating from South-Young High School in 1989 in Knoxville, he moved to California to become an actor. In the beginning, Knoxville appeared mostly in commercials and made several minor appearances as an extra. When the "big break" he sought eluded him, he decided to create his own opportunities by writing and pitching article ideas to various magazines. An idea to test self-defense equipment on himself captured the interest of Jeff Tremaine's skateboarding magazine Big Brother, and the stunts were filmed and included in Big Brother's "Number Two" video.