Based on the work of Monash University, the study was carried out to define the animal growth model mathematically. After the modeling studies, it is concluded that it is biology, not physics, that defines life.
The popular view that physical constraints explain biological patterns has been debated by researchers from Monash University.
The mathematical model of animal growth, showing how researchers focus their energy on growth and reproduction as animals age and grow, is presented in a study just published in Science.
"Evolution has shown it to be extraordinarily adept at finding gaps," said lead study author Professor Craig White, from Monash University's School of Biological Sciences and Center for Geometric Biology.
"Living organisms can't break the laws of physics, but evolution has shown them to be extraordinarily adept at finding gaps."
The disproportionate (allometric) link between energy metabolism and size is a mystery in biology.
Professor White said: "We're in the wrong place when it comes to finding solutions to why this common pattern is occurring. Finding that an animal's metabolism can be described without resorting to physical limits suggests we're looking in the wrong place. ”
"We believe that evolution has a wider range of alternatives than previously imagined, and that physical constraints do not drive the biology we observe as much as we previously assumed," he added.
During growth or evolution, an increase in size is usually followed by a disproportionate increase in energy needs.
In gram-for-gram comparisons, larger creatures consume less food and expend less energy.
For example, small mammals such as shrews may need to eat up to three times their body weight each day, while baleen whales, the largest mammals, only eat krill between 5 and 30 percent of their body weight each day.
What is Krill?
Euphausiidae is a family of animals belonging to the order Caprelloidea. The origin of the word krill, which was translated into Turkish from French or English, is Norwegian.
Although they are very small (1–2 cm), they reach large sizes (500.000.000 tons) in flocks. They generally live in cold waters and their main food is phytoplankton forming diatoms. Krill are the main food for many whale species. Seabirds such as penguins and albatross also feed on krill.
According to Professor White, "Our analysis challenges the common notion that biological patterns such as allometric scaling originate from physical boundaries."
We developed a mathematical model of animal growth showing that lifetime reproduction is maximized when metabolism grows disproportionately to size. “As animals age and grow, they change their energy allocation from growth to reproduction.”
“Our model does not contain physical or geometric limitations, unlike many other models that have been proposed to explain this model since the early nineteenth century. In other words, contrary to traditional beliefs that animals do because they need metabolism, we now know they do it because it's for the best."
According to Professor White, the study showed that allometric scaling need not be due to geometric or physical constraints. Instead, allometric scaling is supported by natural selection rather than physics.