14 DAY TRIAL // For quite some time now, evolution experts have believed that animals evolve depending on their environments alone, adapting to the challenges that appear over the years, and becoming best fit to live in certain areas. But a new research comes to prove that other factors are at work in determining the speed at which animals evolve. It shows that lower altitudes and lower elevations help speed up microevolution, especially if warm temperatures are involved. The “extra” speed is given by the fact that higher temperatures increase metabolic rates, ScienceNow reports.
While this has been known to be true for plants for a long time, until now, no conclusive evidence has been found that the same line of thought applies to mammals as well. Warm-blooded creatures are, apparently, influenced by the same factors as plants are. Higher metabolic rates allow them to grow faster, and also favor mutations, which are the main engine behind evolution. Also, we reported earlier that plants living closer to the Equator and Tropics reach, on average, up to 30 times the height of those living at higher latitudes, near the Arctic and Antarctic Circles, for example.
Most biologists believed, however, that mammals were immune to the evolutionary effects of temperatures in their environments, mostly because these animals, which include humans as well, tended to have bodies that maintained a relative constant inside temperature. For example, the human body usually runs at 36 degrees Celsius, and a temperature higher than that may be an indicator that something is wrong with us.
However, when studying patterns of mammal biodiversity, Auckland University of Technology Evolutionary Ecologist Len Gillman, from New Zealand, discovered that a connection existed between temperatures and development. “I thought, 'There's got to be a universal explanation,'” he said. The expert mostly analyzed the fact that low elevations and areas near the equator seemed to foster a large number and diversity of species, while higher altitudes and regions near the poles not that much so.
In a study published in the June 25th issue of the respected scientific journal Proceedings of the Royal Society B, the researcher and his team propose that species living in warmer conditions and at lower elevations evolved, on average, about 1.5 times faster than others. One of the main reasons for this, Gillman revealed, could be the fact that animals living in colder conditions tended to hibernate, or be less active, so as to preserve energy, a necessity that does not exist in warmer climates.