Monday, April 27, 2015

Silvapithecus Americanus - Will DNA be the final word if a specimen is taken?

What will DNA tell us about Bigfoot?
If and when a Bigfoot specimen is taken, it is expected that the DNA results will help place the Bigfoot somewhere in the ape-human family tree. Don't be so sure. 

DNA is not the be-all, end-all 'blueprint' when it comes to defining differences and similarities between species like the great apes and humans, or for that matter, any species.  There is also morphology to consider. (Wiki describes Morphology as a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance (shape, structure, color, pattern), i.e., external morphology as well as the form and structure of the internal parts like bones and organs, i.e., internal morphology or anatomy.)

You've probably heard that humans are most closely related to the great ape, the chimpanzee. Nucleotide mismatches with humans occur in the African great apes, as is determined by DNA hybridization, at the rate of 1.1%. Humans and orangutans differ by a factor of 2.4%. That's a pretty close genetic similarity.*

Yet, as small the percentage is, why aren't chimps and humans almost identical in a morphological sense? (i.e. why don' t they look more alike?) * Did you know that human males differ from human females in their DNA by about 1.5%. A major reason is that the male Y chromosome is much smaller female X chromosome. If you took only the percentage differences, wouldn't you conclude that human males are more closely related to chimps than human females? The difference, of course, is that human males and females are much more similar to each other morphologically. Some of these are derived features of the Homo sapiens species. (In the study of evolutionary relationships, derived refers to traits that exist in a present organism, but did not exist in the organism's ancestors.)*

Let's talk about another great ape, the orangutan. There are two species of orangutans, Bornean and Sumatran. The mitochondrial DNA difference between these two very similar species exceeds that between humans and chimpanzees. Yet, the two types of orangutans are much more similar to each other morphologically than humans are with chimps.* As an aside, I think the study of orangutans is very important because the possible ancestors of Bigfoot are Sivapithecus and the later Gigantopithecus, both who have strong ties to current day orangutans.

The comparison of gene sequences is not enough. Importantly, it's the effect of communication between regulatory genes and RNA, so-called genomic processes that is going to result in an improved understanding of evolution and genes.
(*ideas from 'The Red Ape' by Jeffrey H. Schwartz)

So, what's my point?

When that big, hairy ape's DNA is truly taken from a valid specimen, expect there to be more questions than answers about whether it is human's closest relative. The morphology of the creature should be considered. There is no scientific justification to favor DNA over morphological data.

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