The best Marvel movie of 2022 reveals an incredible quirk of human evolution

About 365 million years ago, our fish ancestors evolved limbs that allowed them to move out of the water and onto land – forming the evolutionary bridge for all terrestrial land mammals that would one day inhabit planet Earth, including humans.

Though we are hundreds of millions of years removed from our ancestral transition between water and land, humans maintain a special relationship with the ocean – a relationship beautifully illustrated in Marvel’s latest science fiction epic sequel, Black Panther: Wakanda Forever.

Spoilers ahead!

The film pits the people of Wakanda against the Talokan – a society of people inspired by real-life Mesoamerica and led by the serpent god, Namor, who evolved centuries ago to live and breathe underwater. In the film, Namor explains how his ancestors were being besieged by white settlers. They sought guidance from the god Tlāloc, who led them to consume a blue plant.

“The plant took away their ability to breathe air but allowed them to extract oxygen from the sea,” Namor told Princess Shuri of Wakanda. Namor is the only one who can survive on both land and water, but the rest of his people have adapted to an exclusively aquatic lifestyle.

So the people left their settled lands and fled to the sea, forming an underwater refuge known as Talokan. Through this device, wakanda forever shows a fictional example of humans returning to the water for safety. The film’s premise offers an opportunity to re-examine our uniquely human relationship to life at sea versus on land – including a group of real-life people whose society is strikingly similar to Talokan. Let’s dive in (pun not intended).

Reel Science is an Inverse series that reveals the real (and fake) science behind your favorite movies and TV shows.

How did our ancestors come to earth?

Roughly between 360 and 400 million years ago, a group of four-limbed animals known as tetrapods made their way out of the sea and onto land, setting the stage for life on Earth as we know it – including our own human existence.

Tetrapods basically descended from the last common ancestor of reptiles, amphibians and mammals. In 2006, scientists first published research on a “tetrapod-like” fish called Tiktaalik, that likely served as a transitional fossil between fish whose limb-like fins helped them navigate shallow water and the terrestrial tetrapods that followed.

Robert Gess, a paleontologist at the Albany Museum in South Africa, said Discover magazine that tetrapods likely moved into the ocean to “exploit” a resource free of their oceanic predators. In evolutionary parlance: they fled to earth for safety—a reversal of what Namor and his people would do hundreds of millions of years later.

But strangely, there is also an evolutionary precedent for returning Land to Sea – Namor and his people are far from the first living beings on Earth to dive back into the ocean. Whales actually evolved from a group of land mammals that lived near riverbanks in present-day Pakistan. And last year, scientists reported on a species of fish that evolved to walk on land but returned to the water.

“You had this evolutionary series of fish evolving to walk, but this one said, ‘Eh, I’m not going to do that. I’m going back,'” said Neil Shubin, co-author of the study. NPR.

Other species such as the salamander Crassigyrinus scoticus lived “secondary” aquatic lifestyles, meaning they could technically live on land, but their reduced forelimbs made terrestrial life difficult, so they largely adapted to return to an aquatic lifestyle. Modern examples of minor aquatic animals include polar bears and penguins.

Did humans previously evolve to live in water?

If humans had evolved to live completely underwater, they probably would have had to be somewhere around 1000lbs to have enough insulating fat that we could move quickly to find food in extremely cold water. That 1000-pound figure comes from a 2018 study by scientists at Stanford University.

Therefore, the muscular and lean physique of Talokan people is probably not really good for underwater life. Although humans didn’t grow up to such great weights, some scientists still maintain that water was the key to human evolution.

The prevailing wisdom today is that humans descended from treetop-dwelling primates to live an upright, bipedal lifestyle through a series of terrestrial evolutionary adaptations over millions of years. But there’s still significant room for dispute about how or why humans evolved the way we do.

In the 1960s, marine biologist Alister Hardy proposed a now-discredited “aquatic ape” hypothesis, which purports to explain why humans evolved distinctive traits—hairlessness, subcutaneous fat, bipedalism, etc. – which our closest primate relatives lack. The highly controversial theory suggests that our hominid ancestors lived a “semi-aquatic” lifestyle – eating mainly tropical fish and tubers.

As these ancient people spent significant time in the water, they developed features more common in aquatic mammals, such as large brains, breathing, and subcutaneous fat to keep us warm in the water. Bipedalism, according to this hypothesis, arose to help humans keep their heads above water.

But there is little evidence to support the aquatic ape hypothesis, such as fossils demonstrating a semi-aquatic lifestyle. Critics claim that aquatic ape proponents are enamored with simple “umbrella” hypotheses that attempt to offer a single explanation for why humans have a unique set of evolutionary traits, when those traits are more likely to have evolved in one series of complicated adaptations over a long period of time. time.

To be blunt: unfortunately, none of our ancestors were likely living the water life like the people of Talokan.

The real people who evolved to thrive underwater

The aquatic ape hypothesis may be disputed, but science has proven how a real-world group of people evolved to live at least partially underwater – the closest equivalent we have to Talokan on Earth.

Known as the “nomads of the sea”, the Bajau people of Southeast Asia have survived for a thousand years in the sea by diving to depths greater than 200 feet in search of meals, requiring them to hold their breath for several minutes at a time.

According to a 2018 survey published in the journal cell press, the Bajau evolved larger spleens to help deliver more oxygen while diving. When mammals dive, their spleens contract and release oxygen-carrying red blood cells, increasing their oxygen by up to 10%. Scientists have found that the spleens of the Bajau people are up to 50% larger than those of neighboring groups that do not interact with the sea.

Most of us are not genetically gifted with enlarged spleens, but you can train yourself to learn to hold your breath longer than average. Kate Winslet reportedly broke an acting record by holding her breath underwater for seven minutes to Avatar: The Way of Waterand Tenoch Huerta – who plays Namor in wakanda forever – came to an impressive five minutes.

So, with a little practice, you could probably live underwater like the Talokan too – if only for a few minutes.

Black Panther: Wakanda Forever is now streaming on Disney+.