Dinosaurs vs. microbes

Allison Cartwright is our ECS Publications Officer. As a lifelong dinosaur obsessive, she pondered the possibilities and dangers of species revivalism. 

With the new Jurassic World film on the horizon, I’m returning to my childhood obsession of dinosaurs. My room is still full of dinosaur books and models, including the Lego velociraptor ‘Blue’ from the last Jurassic World film.

Can we resurrect dinosaurs? In one of my favourite books, Bring Back the King, the new science of de-extinction, Helen Pilcher explored the possibilities of recreating the dinosaurs. She wondered if modern molecular biology techniques could be used to extract DNA from fossils to create a walking relic. There hasn’t been a fossil found with detectable DNA, so this route offers little opportunity for the de-extinction of these special reptiles.

It was the Nobel Prize winning chemist Tomas Lindahl who worked out that DNA has a half-life of 521 years. This means that no trace of it could survive longer than 6.8 million years, about a tenth of the time since dinosaurs last roamed.

Lego Jurassis

Birds of a feather

Pilcher explored the option of turning to the dino’s closest living relatives. If birds evolved from dinosaurs, could their genes be manipulated to create an organism with dinosaur features?

Helen spoke to researchers who’ve manipulated chicken embryos to grow teeth instead of beaks and leg with claws instead of wings. It’s crucial to understand that these scientists weren’t trying to create a freaky chicken zoo, nor roaring giant pigeons, they were studying the way embryos develop.

“These are people that work in human research, and they study things like how hands are formed or why a snout is different to a beak,” says Pilcher.

Although these manipulations are possible by altering the codes for specific proteins, for ethical reasons, the eggs are not allowed to be hatched. This means the bird-dinosaurs may not be able to survive, and perhaps we’ll never know.

dinosaur-egg

Nature is complex

The real difficulties lie not so much in the limits of technology, but by almost everything else. An animal isn’t just a living being in isolation: it’s one tiny part of a much larger biome, an intricately working machine in fragile balance.

Several of the species one might consider for revivalism are herd animals. This means these animals can’t be brought back in isolation. One can’t bring back woolly mammoth without bringing back several dozen, enough so that they can breed, flourish and thrive.

pterosaur

Time travel

So, we are still a long way from having a living dinosaur, but hypothetically, what would happen if we bought them back? Would they survive our current microbes? Imagine for a second, if Dr Who collected a zoo-full of dinosaurs with the Tardis and brought them to present day. These reptiles would only have an immune response to microbes from 65 million years ago.

A single bacterial cell can divide to form millions of cells in less than a day. If a mutation occurs, the bacteria could change in a timescale of days. Since dinosaurs have been extinct, bacteria have had over 2 billion days to form new strains and species while the dino’s immune system has been locked at a point 65 million years ago.

street-art-dinosaur

Vive la résistance

Although we can easily work out how fast bacteria grows, it’s more difficult to estimate the rate at which new pathogenic strains will be created. It is also hard to predict what microbes would be pathogenic to the dinosaurs. Antibiotic resistance in bacteria has been documented since the discovery of penicillin in 1928.

The ability of bacteria to develop or share resistance traits has resulted in major research efforts, a concept which has accelerated in less than a century. This makes the changes in microbes over millions of years seem impossible to grasp, in the same way I can’t imagine the world as a single continent.

dinosaur toys

The dino dream

Resurrected dinosaurs would probably have to be kept on high doses of antibiotic, thus helping to fuel the spread of antibiotic resistance microbes. Ultimately, I think the result would be the re-extinction of the dinosaurs.

But at least this time, we would be certain of the cause – microbes. I hope I’m wrong and pet dinosaurs could be a hope of the future. Imagine the beauty of working with a big critter that hasn’t been seen for millions of years! If anyone out there is creating a living dinosaur, especially a carnivore, can I please volunteer to work for you?

References

Pilcher H. (2016) Bring back the King, the new science of de-extinction. Bloomsbury Sigma, London.

 

Pray L. (2008) Antibiotic Resistance, Mutation Rates and MRSA. Available from: https://www.nature.com/scitable/topicpage/antibiotic-resistance-mutation-rates-and-mrsa-28360



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