Frogs physically fit quickly genomes change, according to a new study of the poison frogs of Central and South. Segments of DNA changes accumulate over time, but the rate at which these changes accumulate varies considerably between species, said author John C. Saints of the National Evolutionary Synthesis Center in Durham, North Carolina fitness frog .
In the past, biologists try to explain why some species are more rapidly evolving genomes that others have focused on characteristics such as body size, generation time fitness frog , fecundity and life. According to one theory, first proposed in the 1990s, the increased metabolic rate remaining species are likely to accumulate DNA changes at a faster rate, especially in cold-blooded animals such as frogs, snakes, lizards and fish . However, subsequent studies have failed to find support for the idea fitness frog .
The problem with the above tests is that they base their measurements of metabolism in animals at rest and not during normal physical activity, Santos said fitness frog .
"The animals rarely stop there," said Santos. "If you go in nature, see animals hunting, breeding and racing to avoid being eaten. Energy cost of these activities is beyond the minimum amount of energy that an animal needs to function" fitness frog .
Fitness frog to test this idea, Santos toured forests in Colombia, Ecuador, Venezuela and Panama in search of poison frogs, subjecting nearly 500 frogs - representing more than 50 species - an aptitude test to the frog fitness frog.
He frogs running on a plastic pipe like a wheel spinning hamster and measured oxygen consumption after four minutes of exercise fitness frog .
Friskiest frogs had aerobic capacities that were five times higher than the slower species, and were able to run longer before tiring fitness frog .
"Physically fit species are more efficient at extracting oxygen from each breath and deliver to the muscles," said Santos.
To calculate the speed at which the genome of each species change with time, but also restored the tree poison frog, using DNA sequences from fifteen frog genes.
When calculating the number of mutations or changes in the DNA of each species over time, a clear trend has emerged - Sports frogs tend to have more rapid evolution of genomes.
Santos has tried other factors and body sizes and clutch, but athletic prowess was the only factor that correlates consistently with the pace of change.
Fitness frog why frogs genomes faster setting change remains a mystery. One possibility is to do with harmful molecules called free radicals, which increase in the body as a byproduct of the year.
During exercise, the circulatory system supplies blood and oxygen to the tissues that are needed - the muscles - at the expense of less active tissues fitness , Santos explained fitness frog .
When physical activity has stopped the flow of blood and oxygen flow is restored when these tissues produces a burst of free radicals which can cause wear in the DNA, causing genetic changes that - if they affect the DNA of cells producing eggs or sperm - can be transmitted to future generations fitness frog .
Before you ditch your exercise routine, Santos offers some words of caution. The results refute the benefits of regular exercise fitness frog , which is known to reduce the risk of cancer, heart disease and diabetes fitness frog .
"What is true for cold-blooded animals such as frogs poison does not necessarily apply to warm-blooded animals such as humans," said Santos.
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