User:Marshtyl001/Sex-limited genes

Plans

 * I have found grammatical errors through out the article that I already have or plan on changing.
 * The Lead Section is missing key information and examples regarding sex-limited genes.
 * The lead section is also missing a summary of the history and epigenetics section of the article.
 * The lead section has used some terms that aren't the actual terms.
 * The lead section didn't talk about how the phenotype compares and contrasts to sex-linked genes.

Draft of Changes
Sex-limited genes are genes that are present in both sexes of sexually reproducing species but are expressed in only one sex and have no penetrance, or are simply 'turned off' in the other.

However, the resulting phenotypes caused by sex-limited genes are present in only one sex and can be seen prominently in various species that typically show high sexual dimorphism.

Sex-limited genes were first hypothesized by Charles Darwin and though he was unsuccessful in distinguishing the previously mentioned sex-linked traits, his hypothesis was the starting point for future study of the subject. His studies on sex-limited traits have been further substantiated and supported over time, distinguishing sex-limited genes and sex-linked traits. Modern study of sex-limited genes includes research on epigenetics, which is the study of inheritable phentotypic changes with no change in DNA sequence. Modern research suggests that a substantial portion of the expression of sex-limited genes and sexual dimorphism may be influenced by certain epigenetic marks.

This phenotypic variation can play a key role in the evolution of various species and their sexual differentiation.

Sex-limited genes are typically the reason why a species phenotype can vary so drastically between sexes regardless of genotype.