A rare mosquito fossil complete with traces of its last meal of 46-million-year-old animal blood has been discovered, but even though this might sound like the beginnings of the Jurassic Park dream, scientists have been quick to point out there are a few reasons why that cannot happen.
The female specimen was recently found in oil shale in northwestern Montana as one of 36 mosquitoes recovered from what is known as the Kishenehn Formation.
It is regarded as valuable because when it was donated to the National Museum of Natural History in Washington, D.C., the specimen’s abdomen was noticed to be dark and distended: meaning that not long before it had died, it most likely had fed and the contents of its meal, the blood of another animal, might also have been preserved.
Researchers set about ascertaining whether there were any traces of blood by bombarding the fossil with molecules of bismuth to cause chemicals in the fossil to vaporize. They then tested that vapor using a mass spectrometer, which identifies chemicals by their atomic weights. What they found were traces of heme, an organic compound central to hemoglobin, indicating that the iron present in the sample was in fact from blood and not from the fossilization process.
Why is this important? According to George Poinar, a paleo-entomologist at Oregon State University who wasn’t involved in the research, this demonstrates that blood drinking mosquitoes were already feeding 46 million years ago, suggesting they may have been around much earlier than had previously been thought.
The research is made yet more interesting by the fact that the fossil wasn’t preserved in amber, as in the above picture, but rather shale. Lead researcher Dale Greenwalt, of the National Museum of Natural History, told LiveScience that the chances of that happening were “infinitesimally small.”
“The insect had to take a blood meal, be blown to the water’s surface, and sink to the bottom of a pond or similar structure to be quickly embedded in fine anaerobic sediment, all without disruption of its fragile distended blood-filled abdomen.”
Details of the find are published this week in the journal Proceedings of the National Academy of Sciences of the United States of America where the full experiment and its implications are explained.
So, given the recent discussion about bringing extinct animals back by sampling their genetic material, why is it that we can rule out a Jurassic Park style resurrection of dinosaurs?
There are several reasons, but the key one is precisely the reason why in the case of this recent find we can’t tell what animal the mosquito dined on before it died: DNA has a short half-life, with recent evidence suggesting it to be at about 521 years. That means that any sample over one to two million years old would be unusable, putting the 65 million year old dinosaurs, or the 46 million year old animal represented in the fossil, firmly out of reach. That’s not to say all extinct species are beyond our abilities to resurrect, however.
De-extinction is possible and in the case of species like the woolly mammoth or the dodo, is a feasible if still distant reality (relying on many complex processes such as reverse engineering) that has nevertheless proved tantalizing for a great many in the science world and beyond.
There would be a number of problems related to reviving long dead species. Quite apart from the mechanics of it, for instance finding a host species capable of bearing a dodo, a main issue is how to overcome the challenge of engineering enough genetic diversity in the revived species to allow the species to breed successfully and stay alive. That’s no small problem, but it is within science’s reach to answer.
It’s also worth remembering that though dreams of reviving the dinosaurs Jurassic Park-style are now out of reach, the history that yet undiscovered fossils could still teach us remains a living, and extraordinary, prospect.
Photo credit: Thinkstock.
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