SCIENCE

Can Humans Breathe Underwater? The mutation of the BAJAU: super divers in deep waters

YEET MAGAZINE

Sep 21, 2023 • 12 min read

Is it possible to develop a mutation that allows us to breathe underwater?

Updated 1 hour ago

Is it possible for people to develop a mutation that can allow them to breathe underwater ?

Is it possible for people to develop a mutation that allows them to breathe underwater?

THE BAJAU, THE NOMADS OF THE SEA

FAR FAR AWAY AWAY FROM OUR LIFESTYLE, WE STILL FIND PEOPLE LIVING IN HARMONY WITH NATURE. INDISPUTABLY, THE BAJAU ARE ONE OF THEM.

FOR HUNDREDS OF YEARS, THE BAJAU LIVED AT SEA AND THANKS TO THEIR WAY OF LIFE, THEY BECAME EXPERIENCED DIVERS.

THE BAJAU PEOPLE HAS NO COUNTRY, NO CALENDAR, NO LEADER; HE LIVES IN COMPLETE FREEDOM ON THE SEA AND IN SELF-SUFFICIENCY!

These nomadic populations live in the waters that wind between the Philippines, Malaysia and Indonesia, where they dive to fish and search for natural items that can be used in local crafts.

The Bajau are an ethnic group part of populations called "sea nomads" such as the Moken of Burma and Thailand, the Orang Laut of Riau and the Urak Lawoi' of Thailand.
They are the second largest group in numbers constituting over 13% of the population.

The Bajau live mainly on the small islands and coasts of the island of Celebes. The expansion of the Bajau is believed to be linked to fishing and the sea cucumber (sea cucumber) trade.

The Bajau people have no nationality or leader. He doesn't need any hierarchy and, for them, a man is equal to a woman. He lives in total freedom, in permanent communion with nature.

They are also called “Sea Gypsies” because of their constant mobility.

“The bottom of their wooden canoes has a trap door that they open to put their ears to the surface of the water. They listen to the noises made by the fish but also to the seismic movements that shake the ocean floor. This is how they were able to see the tsunami of December 2004 coming and warn the tourists present on the site. The canoe is much more than a simple boat. It is a place of life that must be protected and a mark of identity. They attribute supernatural powers to this boat. »

They live in small houses on stilts to protect themselves when the storm arrives.

The Bajau cannot read or write, and do not have access to modern comfort or the latest technologies. But they live in one of the most beautiful places in the world.

They have an intimate relationship with the sea. From a very young age, they quickly become good swimmers. Adult divers can descend to a depth of more than 70 meters, they have a very good knowledge of the environment.

Most people can hold their breath underwater for a few seconds or even a few minutes . But the Bajau people continue to break freediving records, with some remaining underwater for almost 13 minutes at a depth of around 60 meters.

A recent study published in the journal Cell gives some explanations for their exceptional capacity, notably a possible mutation of their DNA and a greater development of their spleen. This organ supports the immune system and helps renew red blood cells.

Little scientific explanation:

If you hold your breath and submerge your face in a bathtub filled with water, your body will automatically trigger what is called the diving response. Your heart rate slows, your blood vessels constrict. The same goes for your spleen which contracts in turn. All of these reactions help you save energy when you're low on oxygen.

According to certain studies carried out on certain marine mammals such as seals, scientists have observed that their spleens are disproportionately large like those of the Bajau.

The Bajau have exceptional abilities, but they are also a people apart, living in freedom and in symbiosis with the natural elements that surround them.

Their ability to adapt has allowed them to exploit all the potential that nature offers them. They evolve in an idyllic setting surrounded by lagoons and turquoise sea.

The mutation of the I BAJAU: super divers in deep waters

The BAJAUs are a tribe living mainly on the Zamboanga Peninsula and the Joló Archipelago, located in the southwest of the Philippines. BAJAUs are said to be able to stay underwater for up to 13 minutes at depths of 60 to 70 meters

Most "normal" humans hold their breath underwater for 2-3 minutes, but for the Bajau, 3 minutes is practically nothing.

The BAJAUs are a tribe that possesses a strange mutation that allows them to swim freely in sea depths of up to 60 and 70 meters for an extended period of 13 minutes; this ability allowed them to develop the size of their spleens. This is what reveals a study published in the scientific journal Cell, in which scientists from the University of Copenhagen, California, and members of the University of Cambridge collaborated. The Bajaus are known as "sea nomads", who for over a thousand years roamed the coasts of Southeast Asia in Palafitos (houses built on stilts), always subsisting on the resources provided by sea, by hunting with a spear.

Since they never practice this activity as a form of competition, the maximum endurance they can achieve underwater is completely unknown; a tribal member assured investigator Melissa Llardo that he was capable of diving for 13 minutes straight. Llardo told The Atlantic that she dove with Pai Bayubu, an island member who showed her how easy it was to go down into the ocean.

But how is it possible that they can submerge themselves in water for so long?

When you hold your breath, your body automatically activates a cardiovascular response: your heart rate slows, while your blood vessels and spleen constrict. This protection mechanism is intended to help save energy when a limited amount of oxygen is available. In the past, it was assumed that the spleen may play an important role in allowing humans to freely immerse themselves in water for long periods of time. However, the relationship between spleen size and diving ability has never been studied from a genetic perspective. There is now evidence that a genetic adaptation has occurred in some humans, who possess diving abilities superior to those of average humans.

After a few visits to the site, Llardo scanned the bodies of 59 BAJAUS using an ultrasound machine, and found that their spleens were 50% larger than those of the SULAN, a neighboring tribe that did not have this aquatic life .

When the spleen contracts, there is an expulsion of red blood cells into the bloodstream, which promotes an increase in oxygen levels. Some studies estimate that this reaction increases oxygen levels by up to 9% , which extends the time we can stay submerged in water. This genetic adaptation promotes increased levels of thyroxine (thyroid hormone) which, consequently, leads to an increase in the size of the spleen. In research conducted on laboratory mice, the hormone thyroxine was suppressed through genetic modification, resulting in a reduction in the size of the spleen.

This is the first time that a genetic adaptation to diving has been identified in humans.

Which animals can breathe underwater?

As sea turtles are air-breathing reptiles, they need to surface to breathe. Sea turtles can hold their breath for several hours, depending upon the level of activity. A resting or sleeping turtle can remain underwater for 4 -7 hours.

+40 animals that breathe through their gills

Human beings carry out the gas exchange necessary for breathing using their lungs, nostrils, trachea and bronchi. However, fish as well as other aquatic animals, such as some molluscs, amphibians, etc., require specialized organs to obtain the limited oxygen present in the aquatic environment. These organs are called gills.

In this ProjetÉcolo article, we will see +40 animals that breathe through their gills . Do you know them all?You might also be interested in: Animals with multiple hearts

Index

What is branchial respiration?

Branchial respiration is the exchange of gases (oxygen and carbon dioxide) through specialized organs called gills. These organs are located behind the head in aquatic animals . They look like small plaques arranged one on top of the other and whose structure includes multiple blood vessels.

The functioning of gill respiration begins when the animal absorbs oxygen that is found in the water , either through the water current or through an operculum, which is a harder fin that protects the gills and conducts the respiration. water towards them. Once absorbed, oxygen passes into the blood or another internal fluid such as hemolymph. From these fluids, oxygen is transported to the various tissues and organs that need it for metabolism and cellular respiration in the cell's mitochondria.

Once this oxygen has been used and after cellular respiration , carbon dioxide is generated, which is a gas toxic to animals and must be expelled by the body into the environment. Carbon dioxide follows the opposite path, that is, it also passes through the internal fluids and goes to the lungs where it diffuses, to be subsequently expelled through the lungs.

+40 animals that breathe through their gills - What is gill breathing?

Types of gills: external and internal

There are two types of gills in animals that have them. According to research, the origin of both types is the same, but over time they evolved along different paths depending on the needs of the animal. For example, aquatic animals with slow metabolisms are able to breathe with the external parts of their body and diffuse oxygen into internal fluids. These are the two types that exist:

External gills

According to scientists, external gills are the oldest and most common in aquatic animals during evolution. These gills are made up of small plates or appendages on the upper part of the body. This type of gill also has some disadvantages, such as being more easily injured, being more visible to predators, and making movement at sea more difficult.

External gills are most common in marine invertebrates like molluscs, annelids, aquatic larvae, etc. and in certain aquatic or semi-aquatic vertebrates (amphibians) such as newts and salamanders.

Internal gills

These gills are more complex than the external gills. They are located inside the animal, more precisely under the pharyngeal slits, these are the openings which communicate the interior of the animal's body with its external environment. In turn, the gills have blood vessels running through them, oxygenating the body's blood, which is then directed to the body's tissues and organs. Furthermore, this type of gill has a ventilation system that protects the respiratory organs and gives them increased aerodynamics and utility.

These types of gills are most common in marine vertebrates, such as fish .

Examples of animals that breathe through their gills

Now you may be wondering which animals breathe through their gills . Here are some examples :

Frog

Like other amphibians, the frog has gill breathing during its larval and tadpole stages in the water. As adults, the gills disappear and are replaced by cutaneous and pulmonary respiration.

Octopus

This cephalopod mollusk has gill breathing and three hearts. Two of them are responsible for directing the blood necessary for gas exchange to the gills and the third for pumping oxygenated blood to the tissues.

Clam

It has two pairs of gills, which are formed by ciliated lamellae. They also contribute to osmotic regulation, digestion and excretion.

Shark

All species, from the white shark to the whale shark , have gills made of cartilaginous tissue that open and close to allow the passage of water and gas exchange.

Manta Ray

Like the shark, it has cartilaginous gill structures, which are located on the underside of the body, near the base of the dorsal fins.

Sea Hare

It is an elongated and muscular mollusk which can reach 20 cm. Its gills are located only on the right side of its head.

Lungfish or lungfish

Australian and African fish have a dual respiratory system, with lungs and gills, which allows them to live for a long time outside of water. Learn more about them with this article on Lungfish : Characteristics, Habitat and Behavior .

Axolotl

The axolotl is an amphibian, relative of the tiger salamander, endemic to Mexico. It has three pairs of gills that emerge from the base of its head and move backwards.

+40 animals that breathe through the gills - Examples of animals that breathe through the gills

Other animal species that breathe through the gills

Finally, here is an exhaustive list of other animals that breathe through gills :

If you liked this article, we also recommend reading these two other articles on Marine Animals: Characteristics, Types and List and on Seabed Animals .

If you want to read more articles similar to +40 Animals That Breathe Through Their Gills , we recommend that you visit the Unusual Animal Facts category .