Paradox: The more 'big' animals eat, the less physics can explain?

The fact that animals with larger body sizes consume less energy relative to small animals is a conundrum with biology.

If one imagines work like "unraveling the mysteries of the universe" , people will immediately think of distant physical problems: astronomers observing through a telescope the galaxies at the top of the list. , or experimenters "inverse" with elementary particles in particle accelerators.

As biologists try to unravel the deep mysteries of the universe, they also tend to approach physics to explain. But according to a new study published in the journal Science, sometimes physics - the subject of the physical world - also "hands up" with some biological problems.

For centuries, scientists have questioned why, relatively, large animals burn less energy and require less food than small animals. Why does a tiny shrew need to consume 3 times its body weight in food while a giant whale can fill up to only 5-30% of its body weight every day, with The main food is krill?

Relatively speaking, the tiny mouse is more "vital" than the giant whale.

Although previous attempts to explain this "paradox" have relied on physics and geometry, biologists believe that the real answer lies in evolution. The key is optimizing the organisms' ability to have children.

Headache question, physics is also difficult

The first attempt to explain the phenomenon of "rats eat a lot, whales eat less" , or rather, the disproportionate relationship between body size and metabolic needs, took place nearly 200 years ago.

In 1827, French scientists Pierre Sarrus and Jean-François Rameaux argued that energy metabolism should be proportional to body surface area rather than mass or volume. The problem is, metabolism generates heat, and the amount of heat an animal can dissipate into the environment depends on its body surface area.

In the 185 years since Sarrus and Rameaux came up with the solution, many other attempts have been proposed.

African elephants eat even more modestly, consuming 4-7% of their body weight per day.

Arguably the most famous of these is the American study published in 1997 by Geoff West, Jim Brown and Brian Enquist. They proposed a model that describes the movement of essential substances through a lattice. branching tubes, simulating the circulatory system.

They argue that their model provides "a theoretical, mechanistic basis for understanding the central role of body size in all aspects of biology".

The above two solutions are academically similar. Like many other approaches put forward over the past century, they attempt to explain biological patterns by invoking physical and geometric constraints.

The problem lies in evolution

Living things cannot exist despite the laws of physics. However, evolution has proven to be very good at figuring out how to overcome physical and geometrical limitations.

In their new study, biologists at Monash University decided to see what would happen to the relationship between metabolic rate and size if physical and geometric constraints were ignored.

They developed a mathematical model that shows that animals spend most of their energy early in life growing, and when they reach adulthood, most of their energy goes to reproduction.

They tried to determine which factors in animals' lives influence fertility in their lifetimes, and found that larger but more energy-efficient animals like the whale example above, more successful in having children.

In other words, it was natural selection that did its job and made the above physics confusing . American biologist Theodosius Dobzhansky once famously said: "Nothing can explain biology except to put it in the light of the theory of evolution".

In short, sometimes biology and life are so magical that they create what seems to be "miracles" in the physical world.