Historically, creationists have explained the diversity in created kinds primarily in terms of initial created variability, Mendelian inheritance, chance deleterious mutations, and natural selection. Baraminology research suggests that some animal kinds represented by a single pair on the ark less than 4500 years ago have diversified significantly and are now represented by entire families. This suggests that other mechanisms are present that generate diversity to allow animals to adapt. Research on the RNASE gene in Old World monkeys suggests that programmed adaptive genetic changes were involved in gene duplication and subsequent nonrandom adaptive mutations.The Universal Deluge: Alternative Hypotheses for Hardground Origins