Wrinkles, age spots, gray hair and loss of hair, reduced muscle volume – all external signs of human aging. They are known to everyone, because most people live to old age.
As for animals, to determine by their appearance “aged” individual is more difficult. Especially if we are talking about wild nature, where many animals do not die from old age, but because of lack of food, predators, after mating and so on,reports News.
However, experts know the characteristic age-related changes in mammals, it is not always noticeable in appearance. This, for example, changes in the cells, wear neobessudte structures like the teeth or horns, blurred vision, bone fragility, and so on.
But perhaps the most difficult to figure out how old the insects. Their life cycle is very short, and still was not quite clear, whether taking place in their body and any “age” changes.
The answer to this question is found researchers from Exeter University in the UK. In the new work, they set the example of crickets proved that insects are “age” shortly before his death. And this is manifested, first and foremost, the loss of some physical abilities.
The authors explain that until now, the study of the aging processes of insects was conducted, as a rule, under laboratory conditions. Guinea pig lived to “old age” because they were protected from the dangers of wildlife but it was still difficult to understand how and what “senile” changes manifest in the real world.
So biologists decided to conduct observations of field crickets in the usual habitat of the latter. They have installed more than 130 cameras and monitored a population of wild insects, recording data every hour of their lives.
Specialists, in particular, observed the reproduction of insects, their survival, behavior in times of danger (meeting with a rival or predator) and so on. The study lasted ten years and involved many generations of crickets (the life cycle of adults is a few weeks away).
“Like humans, the crickets are really getting old. Although we did not find evidence that this view supports the strategy of “live fast, die young”, it turned out that insects that spend more energy on reproduction at an early age, manifest some signs of a more rapid loss of strength in old age,” says lead author Rolando rodríguez-muñoz (Rolando Rodríguez-Muñoz).
According to him, the crickets made more “reproductive effort” in his youth, over time, began to exhibit a more pronounced “senile” symptoms. They issued less attractive to females sounds and increasingly lost in battle to their opponents.
“In biology remains not resolved the issue: why do we “fall apart” when you get older. Aging can be associated with the inevitable extinction, and transmission of our genes. In other words, we age because instead of having to use energy to maintain itself, we put it in reproduction,” explains co-author Professor Tom Tregenza (Tom Tregenza).
In a scientific paper published in the journal Evolution, experts note that to analyze the behavior of crickets from the point of view of the theory of disposable soma, which clarifies the evolutionary origin of aging process. According to this model, all individuals make choices, how to manage their resources in favor of the reproduction or to maintain its own vitality. For example, those species and populations that have a small number of external threats and low reproduction rate, should invest much more in their own protection than animals that have short life span and reproduce quickly.