Maybe this isn’t the worst of times, but it certainly isn’t the best. The end of the pandemic is not in sight. The world is warming, the seas are rising and polar bears are heading towards extinction. And then there’s the taxes, the 9am-5pm workweek, the renewed threat of nuclear war.
As people looked for someone to blame besides themselves and all of humanity, one culprit emerged in the form of a 375 million year old fish, specifically tiktaalik. Modern problems would not exist if our ancestors had never left the water, one thesis said. The tiktaalik’s four crooked feet made the fish an easy target.
In 2006, artist Zina Deretsky made a scientific illustration of tiktaalik for the National Science Foundation. More recently, her depiction of the tiktaalik as a fish about to leave the water has become the basis for a series of memes.
In one, the fish is greeted with medieval weapons and premonitions: “If you see a hideous beast evolving, push it back.” Memes suggest hitting tiktaalik with a rolled-up newspaper or poking it with a stick — anything to throw it back into the water and save us from having to work and pay rent.
When Deretsky first saw one of the memes using his tiktaalik illustration, he thought he might feel sorry for him. “Our world is kind of rough today,” he said.
Scientists may never know exactly why fish like tiktaalik and early tetrapods — four-limbed vertebrates — moved to land, said Alice Clement, an evolutionary biologist and paleontologist at Flinders University in South Australia. “Was it to look for more food, escape predators in the water, find a safe haven for their developing young?” asked Clement.
Be that as it may, their legacy is enormous. The group of fish that moved to land gave rise to nearly half of all vertebrates today, including all amphibians, reptiles, birds, mammals, and us. And while we probably can’t trace our family tree directly back to the tiktaalik, “an animal very similar to it was a direct ancestor of humans,” said Julia Molnar, an evolutionary biomechanist at the New York Institute of Technology.
If tiktaalik is our ancestor, then perhaps holding it responsible for the chaos it sowed is an expression of love.
The “Scrolling Age”
Tiktaalik became known to humans in 2004 after skulls and other bones from at least ten specimens turned up in ancient creek beds in the Arctic’s Nunavut Territory. The discoverers, a team of paleontologists that included Neil Shubin of the University of Chicago, Ted Daeschler of the Philadelphia Academy of Natural Sciences, and Farish Jenkins of Harvard University, described their findings in two articles in the journal Nature in 2006.
A council of Arctic elders known as the Inuit Qaujimajatuqangit Katimajiit was consulted, and they named the tiktaalik, which in the Inuktitut language means “large freshwater fish that lives in shallow water”. The fossils have now been returned to Canada.
Scientists have been searching for decades for a fossil like the tiktaalik, a creature with forming limbs. And if other fossils required a bit of an explanation, the tiktaalik’s obvious anatomy – a fish with (almost) legs – made it the perfect icon of evolution, situated directly between water and land.
Still, the fossil fish hit a sore spot, emerging shortly after a trial in Pennsylvania that ruled against teaching creationism as an alternative to evolution in high school biology. For Shubin, society’s collective desire to throw tiktaalik back into the water is a relief: You’d only want to throw the fish if you believed in evolution, “which to me is a beautiful thing,” he said.
When Deretsky portrayed the tiktaalik, he did so with its back submerged in water, as that half of the fossil was a mystery at the time. But over the next few years, scientists amassed more than 20 specimens and got a better look at its anatomy, including its pelvis, rear fin, and skull joints.
In particular, CT scans taken by Justin Lemberg, a researcher in Shubin’s lab, allowed the scientists to peer inside the rock to see the bones. The scans generated 3D models of the invisible parts of tiktaalik. Some scans unexpectedly revealed that he had massive hips and a surprisingly large pelvic fin. The fish, instead of dragging on just its front flippers, like a wheelbarrow, seemed to use all four to get around, like a jeep.
Further examination revealed the delicate bones of his pectoral fin. Unlike the symmetrical rays of fish fins, the tiktaalik’s fin bones were noticeably asymmetrical, which allowed the joints to bend in one direction. “We think it was because these animals were interacting with the soil,” said Thomas Stewart, a new evolutionary and developmental biologist at Penn State University.
Tiktaalik’s fins present a special fascination for researchers investigating the genetic underpinnings of human hands. Tetsuya Nakamura, an evolutionary developmental biologist who hopes to genetically manipulate a zebrafish so that it develops fingers, hung illustrations of the tiktaalik’s fin in his lab: “The ideal image we want to create here,” said Nakamura.
The tiktaalik’s existence was perfect in other ways. There were many fish in the Upper Devonian, a peaceful version of Earth when the weather was pleasant and mild and the seas teeming with life. The tiktaalik may have spent its days wandering along the banks of streams and plant-filled swamps, Daeschler said.
This era on Earth was a strange time to be a vertebrate, according to Ben Otoo, a graduate student at the University of Chicago who is researching early tetrapods. Vertebrates that ventured ashore were still forming their terrestrial legs. “It was a lot of galloping, squirming, sliding, huffing, thrashing,” they said. “It’s literally the age of the jolt.”
Other land-curious fish or early tetrapods seemed no less ridiculous. Before tiktaalik, the flat-skulled Panderichthys swam in the shallows. Later, Acanthostega boasted a recognizable but underwhelming set of limbs. And Elpistostege, a fish very similar to tiktaalik, was also on the boundary between fin and hand.
So if modern humans want to blame tiktaalik for our problems, it seems only fair that we blame all the other early inhabitants of the earth – those already known and those yet to be discovered – for ushering in self-awareness and IR forms.
The fish that launched a thousand memes
To be fair, not even the adult tiktaalik could have foreseen this; he didn’t have a grand plan to colonize the land. “It’s not like, ‘Oh, it’s better to have limbs,'” Daeschler said. “Or that animals saw things on earth and thought, ‘Oh, I need to evolve.'”
It is also an exaggeration to say that aquatic fish walked ashore in any significant way. Instead, Daeschler suggested, tiktaalik was exploring new ecological opportunities at the water’s edge, scouring the shallows where limbless fish couldn’t move.
And would-be tiktaalik fighters must know that a mere twig would not be enough to stop an adult. Although the reconstructions of its face look “innocent and idiotic”, according to Stewart, the fish was as big as a person. “It changes the way you think about him from being a bit fragile to a more imposing animal in the water,” Stewart said.
Art does not need to mirror reality to convey a truth. Tiktaalik memes don’t just offer a scapegoat for modern malaise. They also ask us to imagine a different past, present and future. What would happen if we could remap the course of evolutionary history?
“It’s a really powerful idea, and I don’t think there’s anything inevitable about the path evolution has taken,” Molnar said of the memes. “If you turned back the clock, you’d end up in a completely different place,” she added, paraphrasing biologist Stephen Jay Gould.
So if tiktaalik means repentance, it also means radical possibility. For Otoo, the fossil evokes a utopian optimism, a reminder that Earth has had many identities and will have many more.
“The natural world we tend to think of as being immutable and static — you look at things and say, ‘Oh, that’s the way things are,'” they said. But 300 million years ago the continents were all glued into one. Even the Earth can be reshaped over time.
And if the Earth can change so can humans, reasons Otoo. “Through various combinations of conscious and unconscious decisions, we made the world this way,” they said. “And we can do it differently.”
