Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Scenarios for intron evolution: shared ancestral introns versus independent gain. Hypothetical comparisons of intron positions across orthologous genes of distantly related species are shown. (A) Many introns are in homologous positions, suggesting that these introns represent ancestral introns that have been retained. (B) Lack of correspondence between intron positions in different lineages suggest that most introns have been independently gained within each lineage.
