Dinosaurs could be brought back by 'de-evolving' living birds
A British biochemist suggests that the genetic qualities of today’s birds may be the key to bringing back the gigantic “terrible lizards” that ruled the planet during the Mesozoic era.
Dr Alison Woollard believes that it may be possible to reconstruct dinosaur genomes by altering the DNA of modern birds.
Reconstruction through deconstruction
“We know that birds are the direct descendants of dinosaurs, as proven by an unbroken line of fossils which tracks the evolution of the lineage from creatures such as the velociraptor or T-Rex through to the birds flying around today,” says Dr Woollard, who hails from the Department of Biochemistry at Oxford University.
Dr Woollard specifically mentions Archaeopterix – a 150-million year old creature whose name literally means “ancient wing” – as evidence of “the transition between feathered dinosaurs and modern birds.” According to Dr Woollard, it is possible that modern bird DNA contains the genetic instructions for making dinosaurs, albeit “switched off.”
“Could we 'rewind’ evolution by switching these genes back on and using them to guide the development of that bird’s offspring, and its offspring’s offspring, backwards?” asks Dr Woollard. The biochemist also said that scientists could essentially “design” the dinosaur genome, based on available knowledge about the evolutionary relationship between the extinct creatures and their winged descendants.
A 65-million-year-old mystery
Unfortunately, even if such a feat were possible, it probably wouldn't be as simple as just taking apart and then reassembling bird DNA.
Dr Woollard stresses that the main challenge would be in determining exactly what to change or adjust in birds’ genes to be able to reconstruct the dinosaur genome.
In the movie Jurassic Park (which was based on a work of fiction by Michael Crichton), scientists were able to revive the dinosaurs by extracting DNA from mosquitoes preserved in amber over millions of years and splicing the strands with frog DNA.
Unfortunately, recent research from a team based in West Australia revealed that DNA cannot survive for more than 6.3 million years. Since the dinosaurs died out 65 million years ago, this approach does not seem to be a feasible one.
The earliest known sample of creature DNA extracted from a preserved mosquito dates back to about 46 million years ago – a good 19 million years after the last of the dinosaurs faced mass extinction.
Even if it were possible to recover preserved dinosaur DNA, the samples would probably come in very short fragments. Thus, any effort to make a full dinosaur genome would require millions of DNA fragments pieced together.
The next best thing
However, for creatures that existed no more than 6.8 million years ago ago—such as the Woolly Mammoth or the Pyrenian ibex—modern cloning techniques might be possible. Frozen chunks of mammoth tissue were recently unearthed in Siberia, increasing the chances of finding mammoth cells fit for what scientists call ‘de-extinction.’
“The researchers would need to harvest an egg from the mammoth’s closest living relative the elephant, a process that is tricky enough in itself, that has yet to be done successfully, replace the elephant cell’s nucleus with the mammoth nucleus and induce cell division through electric shock,” says Woollard.
“Theoretically, this transgenic egg would develop through cell division into a mammoth embryo and be born as a baby mammoth after a two year gestation period.”
'Can' vs 'should'
On the other hand, Woollard ponders the moral and practical implications of reviving the dinosaurs. Would it be wise to bring back these prehistoric wonders, and could human beings actually live in peace alongside the dinosaurs?
Additionally, does this mean that de-extinction efforts should be undertaken for all the species that humanity had a hand in wiping off the surface of the planet? More importantly, does humanity even have the right to instigate such a massive wave of change across the global ecosystem?
“How far back in time should scientists draw the line?” Woolard asks. — TJD, GMA News
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