Did we monkey around with our genes as different species of early humans interbred and produced offspring of mixed ancestry? In other words, are modern humans part Neanderthal, and is Bigfoot an example of this? (NOTE: Subscribers can still listen to this show).
Recent genetic studies suggest that Neanderthals may have bred with anatomically modern humans tens of thousands of years ago in the Middle East, contributing to the modern human gene pool, but not all scientists accept this, and the fossil record has not helped to clarify the role of interbreeding, which is also known as hybridization.
Now a study of interbreeding between two species of modern-day howler monkeys in Mexico is shedding light on why it's so difficult to confirm instances of hybridization among primates--including early humans--by relying on fossil remains. The two primate species in the study, mantled howler monkeys and black howler monkeys, diverged about 3 million years ago and differ in many respects, including behavior, appearance and the number of chromosomes they possess. Each occupies a unique geographical distribution except for the state of Tabasco in southeastern Mexico, where they coexist and interbreed in what's known as a hybrid zone.
Evolutionary biologist Liliana Cortés-Ortiz says, "The implications of these results are that physical features are not always reliable for identifying individuals of hybrid ancestry. Therefore, it is possible that hybridization has been underestimated in the human fossil record."
Another kind of hybridization would be machine men, which some people think the Grays are. Whitley wrote a wonderful novel about this and subscribers have a coupon that gets them a beautiful hardcover for less than $5!