At the Pinnacle of the Pyramid: Bats – Beyond a Mobile Virus Library, Also a Special Forces Re-Deployment Unit

Bats are flying mammals of the order Chiroptera, the second largest order after rodents, and the only one to have evolved true powered flight. Currently, there are 19 genera and 185 species, totaling 961 known species. Except for the polar regions and remote islands in the oceans, bats utilize virtually every terrestrial ecosystem on Earth. Most bats rest during the day and forage at night.

Bats are a top-tier evolutionary species, bats can use echolocation like radar, and their wings are composed of thin muscle membranes and elastic tissues, combined with overlying skin. The wings are covered with many small blood vessels, and due to the large amount of energy used during flight, body temperature rises rapidly. The small blood vessels on the wings have a wide surface area of contact with air, which helps to dissipate heat. However, the membrane is easily torn, so many bats have holes in their wings. This does not hinder their flight because the membrane also has other ways to assist in flight, and this membrane can recover very quickly. On the bat's membrane, there are thousands of invisible to the naked eye fine hairs. These hairs are connected to precise sensory cells, forming thousands of flight sensors. This allows them to perceive precise airflow speed and direction, thereby controlling flight status, frequency and shape and size, achieving more stable and efficient flight.

Bat's bone structure can drift in the air by 180 degrees, and the wing hairs have sensory cells that calculate air resistance. The brain contains iron oxide, which functions as an internal compass, using magnetic navigation to navigate, even when migrating for up to 2,000 kilometers, it can still find its way home. Bats' hearts are structurally designed to support flight functions, and their heart rates range from 10 to 800/minute … Some bats quickly urinate after feeding blood to prevent flightlessness, which is a remarkable special forces unit.

Of course, it is best known for being the 'virus library'. According to scientists, bats carry more than 4,100 viruses, of which 500 are coronaviruses.

Bats are so toxic because they are the only flying mammals. Because flight requires a lot of energy, bats have a high metabolism. Why do animal lifespans vary? Because different animals have different metabolic rates, and the faster the metabolism, the shorter the lifespan, and the slower the metabolism, the longer the lifespan. This is because the faster the metabolism, the more easily DNA is damaged. According to this, bats should have a short lifespan, but they don't, bats have evolved a DNA repair superpower.

This ensures that cell renewal does not occur in error, which also allows bats to have a super-high lifespan, they have an unreasonably long average lifespan of 30 years, which is much longer than that of similar mammals.

According to the international scientific team, the oldest bats show unique gene expression patterns associated with DNA repair, autophagy (damage removal), immunity and tumor suppression, which are related to age.

This has not been observed in humans or other mammals, and it may drive its extended healthy span. This shows that bats have limited DNA damage and enhanced DNA repair and damage removal levels, which are mediated by new regulatory genes.

And this allows them to have a 24-hour immune system fully open, because as the metabolic level increases, body temperature will also rise—just like a fever, which can shorten the survival time of the disease and increase the survival probability of most animals.

However, except for bats, no other biological species can maintain a constant fever state, only bats can be said to always be at a 40-degree fever. Because they do not have the DNA loss repair superpower of bats.

When our body encounters pathogenic invasion, a series of complex immune protection reactions are triggered. Interferon is the first substance produced when cells are infected, which has a viral inhibitory effect.

As a result, bats have three types of interferons, which is only one-fourth of humans. Although the number is small, the 'work intensity' of bat interferons is higher. For example, even if no virus is infected, bat's Iα interferon is always in an active state, 'on standby' 24 hours a day.

For other mammals, keeping the immune system open for a long time is dangerous, such as it may poison healthy tissues and cells. But for bats with DNA repair superpower, 24-hour immune system fully open will not pose any threat.

It is precisely because they possess these characteristics that viruses are ideal hosts for bats, because viruses cannot harm bats, and bats cannot eliminate viruses.

Although they are 'carrying virus library', in normal circumstances, bats will not infect humans, because for a virus to infect humans, it must find suitable living cells as 'host' to parasitize within them, and then use complex protein-protein interactions (PPI) to forcibly take over the survival function of the host cell to absorb nutrients. Human immune system is unwilling to give in, and it also uses PPI to activate innate antiviral defenses and adaptive immunity to control viral replication.

Viruses are smaller than fungi and bacteria, but in this contest, once the parasitic host cell 'dies', a large number of 'parasites' viruses that rapidly reproduce within its body will tilt outward, re-embarking on a new 'parasitic' journey to infect more healthy cells.

However, in most cases, bat viruses cannot find suitable living cells in humans, they generally need to rely on intermediate hosts to transmit, that is, bat to intermediate host to human.