The Melanesian people probably never thought they’d be so crucial to our understanding of humanity’s origins. But when a group of scientists looked more closely into the DNA of the remote Pacific islanders, they made a startling discovery. And it’s one that could turn our comprehension of our common ancestry on its head.
Melanesia is the name for a broad region of Oceania, including four countries and some smaller islands. Vanuatu, Fiji, Papua New Guinea and the Solomon Islands all fall under the sub-region. And it’s the populations of these areas that sparked the interests of scientists.
The Melanesian islands are separated from the rest of Asia and Australasia by the Pacific Ocean. This means that, potentially, their populations’ ancestries can help to explain how humans traveled across the region hundreds of thousands of years ago.
Previously, genetic analysis showed that their ancestors were made up of two groups of hominids, who bred upon meeting. The first of these is the more commonly known Neanderthal, with whom almost all modern humans share some DNA. The second is less known: the Denisovan.
It’s believed that at some stage between 60,000 and 100,000 years ago, some of our early ancestors left Africa. They went to Eurasia, where they made contact with Neanderthals and Denisovans. And because they bred with their hominid cousins, traces of their DNA entered the Eurasian genome.
Yet while most people are aware of the Neanderthals, few know of the Denisovans. Believed to be a species related to the Neanderthals, they were mainly found in Siberia. However, it appears that they could have been living as far away as Southeast Asia.
Approximately 200,000 years ago, the two hominids split from a shared ancestor. However, it’s thought that they branched from modern humans much further back, around 600,000 ago. And although plenty of Neanderthal fossils have been discovered, barely any Denisovan DNA exists.
Interestingly, while people in Europe have no trace of Denisovan DNA in their genome, the Chinese carry a minuscule 0.1 percent. When it comes to the Melanesian people, however, this figure rises. Indeed, Denisovan DNA has been calculated as comprising as much as 6 percent of their genetic makeup.
It’s no surprise, then, that scientists are so interested in the Melanesian people. After all, they may help us truly grasp our own ancestry by providing more clues about our genetic background.
However, a study published in October 2016 found that there may not be as much Denisovan DNA in Melanesians as previously thought. Statistical geneticist Ryan Bohlender, of the University of Texas, told Science News that the real figure could actually be closer to 1.1 percent.
Clearly, the gap between the two figures leaves space for something – or someone – else. But who or what is a total mystery. The only theory the scientists arrived at was that a third, unknown group of hominids propagated with the ancient Melanesian people.
This discovery sent shockwaves through the scientific community. If true, it proves that the history of humanity is more complicated than previously thought. Indeed, the findings could even change our understanding of evolution.
Bohlender and his team presented the results of their study in Vancouver. They explained, “We suggest that a third archaic population related more closely to Neanderthal and Denisova than to modern humans introgressed into the San genomes studied here.”
The researchers estimate that this third, unknown group split from their shared ancestor some 440,000 years back in time. That means they branched off much earlier than the Neanderthals and Denisovans.
Concluding, Bohlender said, “Overall, our findings confirm the human family tree is more complicated than we think it is. Other archaic populations are likely to have existed, like the Denisovans, who we didn’t know about.”
Indeed, the team’s findings are backed up by another 2016 study by scientists at Denmark’s Natural History Museum. This included an analysis of Melanesian DNA taken from residents of remote Papa New Guinea and aboriginal Australians.
Like Bohlender’s research, the study found a type of DNA that was alike to the Denisovans, but far removed enough that it could not be classified as such. Therefore, the results again pointed to a third type of hominid.
Sadly, there’s no concrete evidence that this third group of early humans even existed. Researchers, indeed, haven’t found any fossils containing the group’s DNA. However, that doesn’t mean the elusive third hominids never were; the rarity of fossils in general indicates that the DNA-containing types could still be out there.
Meanwhile, it’s also possible that scientists’ identification of Denisovan DNA isn’t as accurate as they’d like. Why? Because the only remnants of the species found to date are some teeth and a single finger bone. That’s not much to work with. This is just one reason that Bohlender’s results may not be 100 percent valid.
Still, if Bohlender and his team’s research proves correct, the consequences for the scientific community – and our understanding of our own ancestry – are groundbreaking. Who’s up for rewriting the theory of evolution?
And the incredible research doesn’t stop there, either. Another fascinating study has shed light on a tribe in Asia who have become uniquely adapted to their surroundings. What experts have discovered about these people is truly mind-blowing – and may turn your entire understanding of the human race upside down.
While you may not have heard of them, the mysterious Bajau Laut tribe have certainly earned their fair share of headlines. Why? Well, these people from Southeast Asia live a truly fascinating lifestyle, with each tribe member spending around 60 percent of each day under the waves. And as a result of these aquatic habits, it appears that the Bajau Laut’s bodies have changed dramatically over the years – leading, in fact, to an incredible genetic adaptation.
Sometimes referred to as “sea nomads,” the Bajau Laut live in several different areas around Asian nations such as the Philippines, Brunei and Malaysia. In terms of numbers, meanwhile, it’s believed that the tribe may number over one million people. And as their nickname suggests, the Bajau Laut are often found out on the water.
In fact, the Bajau Laut don’t typically have houses or even places to call home on the shore. Instead, groups operate from boats – known as “lepa-lepa” – that they put together themselves. Then, while out on the water, tribe members scour the seafloor for fish and other items that they can sell on land.
What’s more, as some of the Bajau Laut are underwater for more than half of their working day, they often have to rely on their ability to hold their breath for long periods. And when a group of researchers grew curious about the tribe’s unique lifestyle, they took a closer look at members’ biological make-up – with the results of that study subsequently revealed in April 2018.
In Western society, many of us are able to live our lives more or less as we see fit – whether that’s by settling down with partners and children or by choosing to go off travelling to far-flung parts of the globe. For some people around the world, though, their future lifestyle will be defined for them by previous generations.
Tribes such as the Bajau Laut are somewhat of a case in point, as the sea nomads have been roaming around Southeast Asia for hundreds of years. In fact, you can find records of the Bajau Laut that date all the way back to the 16th century, when a man named Antonio Pigafetta took part in an ambitious project.
A former resident of Venice, Italy, Pigafetta joined the crew of Spanish-sponsored Portuguese explorer Magellan in his 1519 bid to find a new route to India. And in 1521 the explorer made note of an interesting discovery when he came across the Bajau Laut in the ocean.
As for the Bajau Laut’s origins? Well, while stories vary from region to region, most of those tales have one thing in common. It’s said, you see, that tribe members once served an Asian king on the shore, and this monarch was the father of a princess.
From there, the stories diverge in what exactly happened to the princess – although in many cases it’s explained that she ended up going missing. Then, as legend has it, the king subsequently dispatched the original Bajau Laut to bring his daughter back. After the tribespeople ultimately failed to locate the princess, though, they supposedly opted to stay out at sea in order to avoid her father’s wrath.
The Bajau Laut from Borneo believe, however, that their ancestors had worked as guards for a Malaysian royal family. They claim, too, that these predecessors were once tasked to transport their princess to the Filipino province of Sulu, where she would tie the knot with the region’s leader. But, apparently, there was one major issue with this plan.
You see, according to that particular story, Brunei’s Sultan wanted to marry the Malaysian princess as well. And after the Sultan learned that the princess was due to be wed to another, the news reportedly prompted him to send a fleet to intercept the guards. Thanks to that attack, then, the Bajau Laut’s ancestors are said to have lost their royal charge to the Sultan, after which they decided to settle around Borneo. But the various tales don’t end there.
There’s a very different origin story when it comes to the Bajau Laut in Indonesia, for instance. According to this version of events, a princess once got lost at sea during a great flood. Then, after she was retrieved from the water, she apparently went on to marry a member of the Gowan royal family. It’s said, too, that the princess’ children chose the nomadic life of the Indonesian Bajau Laut.
However, some members of the Bajau Laut in the Philippines fall back on a more fantastical fable. In their story, there is no princess; instead, those tribespeople believe that a “giant stingray” transported them to a certain area of the Asian country, leading them to the sea area that they inhabit today.
Regardless of their various origin stories, though, the Bajau Laut’s lifestyle follows roughly the same patterns. Rather than living on the land, for example, they build homes in the water that are held up by stilts and simply use boats to get about.
Plus, as we previously mentioned, the Bajau Laut spend a lot of time underwater, where they hunt for food and potential items to trade. Much like everyone else, though, they face certain obstacles when they swim deeper below the surface. Most obviously, the further down you go into the sea, the more pressure you face – and that’s just as true for the tribe members.
However, the Bajau Laut have a solution for that: they burst their eardrums as youngsters. “You bleed from your ears and nose,” Imran Lahassan told The Guardian in 2010, “and you have to spend a week lying down because of the dizziness. After that, you can dive without pain.”
Meanwhile, when it comes to the equipment that the Bajau Laut use, goggles made from wood with glass lenses are key, as are spear guns that are crafted from materials such as metal and rubber. But while that doesn’t seem like a lot, the Bajau Laut are nevertheless able to make do – and it’s all thanks to an incredible ability.
You see, certain members of the Bajau Laut can hold their breath for extended periods underwater – thus giving them more time to get what they need. In fact, in some cases, it’s believed that these individuals can stay under for close to a quarter of an hour in one sitting. Unsurprisingly, though, such extreme diving can come at a cost.
Yes, while the ruptured eardrums have helped the Bajau Laut divers down the years, the pressures of deep-sea swimming still cause some issues. One of the biggest problems is referred to as “the bends,” which is otherwise known as decompression sickness. And this particular ailment can have a horrible effect on the body.
In fact, Bajau Laut who succumb to the bends can suffer permanent disabilities – even death, in a few cases. The condition occurs when a person dives to significant depths and then swims back up to the surface too quickly. By doing this, they don’t give their body a chance to depressurize at a steady and controlled rate.
Sadly, though, the bends is not the only issue that the Bajau Laut have had to face in recent times. In particular, the Indonesian government has been clamping down on the tribe’s traditional ideals, with the result being that countless members have been coerced into moving onshore.
But despite that obstacle, not everyone has suffered the same fate. In fact, many of the Bajau Laut have been able to erect their own small communities in the water. These towns are held up on stilts, with one such Indonesian settlement taking on the name of Torosiaje.
And the village itself cuts a quite remarkable sight, as it’s located more than half a mile away from the shore. Given its position, though, Torosiaje can prove somewhat challenging to reach – especially if a person doesn’t have an engine attached to their boat. Resident Ane Kasim can certainly attest to this fact.
A member of the Bajau Laut, Kasim lives on her lepa-lepa for about half a year at a time alongside her child Ramdan. During the day, the pair make ends meet with whatever they can find in the water before joining their fellow tribe members in the evening, mooring their boat near the island shore in order to eat and relax.
Yet while Kasim enjoys those aspects of her life, the journey to the village on stilts is hard on her. “I love being at sea,” she told The Guardian in 2010. “Fishing, rowing, just feeling everything – the cold, the heat. [But] when I go to Torosiaje, I have to row. We don’t have anything; my husband died from [decompression sickness].”
Then, roughly five years on from that interview, a scientist named Melissa Ilardo took a trip to Thailand. And while on her travels, the University of Copenhagen geneticist found out about the Bajau Laut. That in turn led Ilardo to visit tribe members in Indonesia with an idea in mind.
You see, a study had previously been conducted into the role of the spleen when swimming mammals held their breath underwater. At that stage, researchers had focused their attention on seals, during which they had noted that the organ in question was larger than expected in the animals. It appeared, too, that the spleen was able to store oxygen-rich red blood cells.
And as the seals boasted particularly big spleens, scientists believed that the creatures could survive without air for longer periods. With that in mind, Ilardo wanted to see if the Bajau Laut were in any way similar, given their ability to hold their breath for minutes at a time. But before revealing what she had discovered, the geneticist touched upon a fascinating point.
“There’s a human dive response that’s triggered by holding your breath and submerging yourself in water,” Ilardo told the BBC show Inside Science in April 2018. “You can trigger it by submerging your face in cold water.” And the spleen apparently had a part to play in this process, too.
Ilardo continued, “Your heart rate slows down, [and] you have peripheral vasoconstriction, where the blood vessels in your extremities get smaller to preserve the oxygenated blood for your vital organs. And then the last thing is a contraction of the spleen. The spleen is a reservoir for oxygenated red blood cells.”
“So when [the spleen] contracts, it gives you an oxygen boost,” Ilardo added. “It’s like a biological scuba tank.” Given what she knew, then, Ilardo planned to test the Bajau Laut when she arrived in Indonesia back in 2015. Yet the researcher didn’t want to dive into the work straight away.
Instead, Ilardo intended to talk with members of the tribe first – even joining them on some of their hunts. And when looking back in 2018, she recalled one of those instances to The Atlantic. On that occasion, she had been following a man named Pai Bayubu when he had caught sight of a clam about 50 feet underwater.
Ilardo told the publication, “[Bayubu] just dropped down. He pointed at [the clam], and then he was there. Underwater, the Bajau are as comfortable as most people are on land. They walk on the sea floor. They have complete control of their breath and body. They spear fish, no problem, first try.”
Then, after Ilardo had gotten to know the Bajau Laut, she came back a little later with an ultrasound device and some “spit collection kits.” In total, 43 members of the tribe were tested, with 33 individuals from a nearby community known as the Saluan also scanned in order to draw comparisons.
Unlike the Bajau Laut, you see, the Saluan lived on land in Indonesia, where they worked primarily as farmers. And once the tests were done, Ilardo and her colleagues went on to look over the results – which themselves were rather shocking. Incredibly, it appeared that the sea nomads had spleens that were around 50 percent larger than the equivalent organs of their shore-dwelling neighbors.
That wasn’t the end of the study’s fascinating findings, either. In addition, the researchers discovered a certain gene in the Bajau Laut’s DNA samples that hadn’t shown up in those taken from the Saluan. The gene in question is known as PDE10A, and it keeps a particular hormone under control in the thyroid gland.
In previous research projects, the PDE10A gene had been found in mice, and the hormone it controlled seemed to be connected to the size of the spleen. Specifically, when the rodents were deprived of the hormone, their spleens turned out to be much smaller than their counterparts who had no such hormonal restrictions. These findings seemed to play into what Ilardo and her colleagues had discovered, then, and the team subsequently published their data in the science journal Cell in April 2018.
In conclusion, Ilardo believed that Darwinian natural selection had come into play for the Bajau Laut as their biological make-up had seemingly adapted to their surroundings. But while the geneticist and her fellow researchers couldn’t pinpoint the exact time when this change occurred, they nevertheless brought up an intriguing figure. According to them, members of the tribe had split away from the mainland some 15,000 years ago.
Ilardo and her colleagues pointed out, too, that such a time frame was a viable period for the adaptation to have happened. And a co-author of the study raised one final point. Speaking to BBC News, Rasmus Nielsen said, “It’s a wonderful example of how humans can adapt to their local environments, but there may be some medical interest in this.”
Nielsen added, “There’s been a lot of interest in understanding hypoxia adaptations – adaptations to low oxygen levels. If you look at trauma medicine, one of the most important factors is the response to low oxygen levels. By studying the Bajau, we can figure out, ‘What are some of the genes that help predict differences in people in how they respond to acute low oxygen levels?’”