While the great white shark can be considered one the oldest
extant jawed vertebrates, surprisingly little is known about its genome. It had
always been assumed that they were closely related to bony fish. However, researchers
from Cornell University and Nova Southeastern University made the shocking
discovery that the genetic makeup of these sharks is actually more closely
related to human beings. The study observed the RNA sequences expressed (
transcriptone) by each of three organisms: the great white shark, zebra fish,
and human being. The comparison was made using heart tissue extracted from the
great white shark. When examining the heart tissue, they found that the gene
products that are associated with metabolism were more similar to that of the
human genome than the zebra fish. There are many theories circulation as to why
this may be possible. According to Mahmood Shivji, the director Save Our Seas
Shark Research Center and Guy Harvey Research Institute, one theory is that it “might
be due partly to the fact that the white shark has a higher metabolism because
it is not a true cold-blooded fish like bony fishes.” It might just be that
sharks are more closely related to mammals than expected.
It is really surprising to find out that the great white shark is closely related to humans. Although the higher metabolism does propose an explanation, this brings up other questions like what other animals could possibly be closely related to humans that we do not know about yet?
ReplyDeleteIt is incredibly surprising that sharks are more closely related to humans than other bony fish. It makes me wonder how else sharks are related to humans besides in ways of their metabolism. As Deb said, I am also curious as to what other animals are closely related to humans that were otherwise thought to be totally different. I recently posted an article where zebrafish were also used in a study! It really is amazing as to how much RNA sequences can reveal about the relation of one animal to another.
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