Much as I love dinosaurs, the Jurassic Park franchise, while fun, was horribly inaccurate. Apple TV’s recent Prehistoric Planet is vastly better, as is the somewhat-short-on-dinosaurs-but-still-good Netflix series Life on Our Planet.
But setting aside our own dinosaurs for the moment, a group of observers looking for biosignatures in nearby star systems make a good point; on our own planet, during the Mesozoic (dinosaur time) the Earth cast a much high biosignature than it does now.
Planets far away from Earth could be harboring species that resemble Earth’s dinosaurs and humans may currently have the ability to find them, according to a new study published in the Monthly Notices of the Royal Astronomical Society journal.
“Modern Earth’s light fingerprint has been our template for identifying potentially habitable planets, but there was a time when this fingerprint was even more pronounced — better at showing signs of life,” study author Lisa Kaltenegger said in a statement to The Sun.
According to the study, researchers on Earth could detect such life by searching for compounds that are not currently present on our planet but were during the age of the dinosaurs. That’s because the Earth had higher levels of oxygen, about 30%, during the time of the dinosaurs, allowing the complex creatures to grow. Today, Earth’s oxygen levels have leveled off to 21%.
Those high oxygen levels could be a clue to the kind of life that exists on a faraway planet, the researchers argue, noting that special telescopes can be used to detect similar conditions to what dinosaurs confronted millions of years ago.
They are, of course, correct about the oxygen levels; that’s another little tidbit that the Jurassic Park movies and other, similar flicks never address, namely that the huge beasts that wandered the Cretaceous would be awfully short of breath on our Earth today. Of course, if that were the biggest scientific shortfall on those movies, that would be another story.
Tangentially, this ties in with a bone I’ve had to pick with the environmental movement and the climate change screechers for some time now; the Earth is now not at all typical of what it has been like through most of the planet’s 4.55 billion year history. It’s been hotter, it’s been colder, oxygen levels have been higher and lower, and so on.
There’s another problem, this one in the linked article’s conclusion:
“Hopefully we’ll find some planets that happen to have more oxygen than Earth right now because that will make the search for life just a little bit easier,” Kaltenegger said. “And, who knows, maybe there are other dinosaurs waiting to be found.”
Hyperbole much? No, on no other planet will we find dinosaurs. There’s no reason to suspect that multi-celled life on another planet would resemble life on Earth in any way. It may not even be bilateral. Its blood chemistry and genetic coding may be completely different. To have an ecology, the planet would have to have producers and consumers, but that’s really the only hard and fast rule. Producers wouldn’t have to be plants as we know them, and consumers wouldn’t have to be animals or fungi. We probably lack the imagination to know all the roads biology might take in another solar system.
And finally, I’ll make my usual comment on dinosaurs being extinct; dinosaurs are most assuredly not extinct. There are more species of the Therapoda alive today than there are mammals. We call them birds.