Delving into the enigmatic secrets of life, scientists uncover a crucial link between genetic mutations and the mysterious tapestry of life spans that span the vast spectrum of Earth’s mammals.
In the diverse world of mammals, lifespan varies drastically; from hamsters living a mere few years to the colossal blue whale, which boasts a record-setting 110-year lifespan. Humans, on the other hand, average around 80 years. The question of why humans outlive many other mammals has long puzzled scientists, but a groundbreaking discovery may finally provide the answer.
The explanation, it seems, lies within a shared element between humans and animals. Research indicates that both species’ lifespans are determined by the accumulation of genetic mutations. This suggests that the genetic damage an organism accumulates over time may play a vital role in dictating its time on Earth.
Previously, it was believed that an animal’s size determined its lifespan, with larger animals like elephants and whales generally living longer than smaller creatures such as rats and mice. However, a new study from the Wellcome Sanger Institute in Cambridge, UK, challenges this notion, positing that it is the number of gene mutations an animal accumulates, rather than its size, that determines longevity.
The study found that larger animals have an innate ability to slow down the rate of gene mutations, which in turn allows them to outlive many smaller mammals. The key to a longer life appears to lie in the creature’s capacity to minimize cellular damage from gene mutations over time.
Supporting this theory, the tiny naked mole rat, with a lifespan of 25 years, lives longer than the average giraffe, which typically survives for 24 years. Despite their size disparity, both species have a similar number of gene mutations; giraffes average 99 per year, while naked mole rats have around 93.
In contrast, mice, which live approximately 3.7 years, amassed a staggering 796 gene mutations per year. Humans, with an average lifespan of 83 years, accumulate significantly fewer mutations annually, at a rate of just 47.
It’s important to note that many gene mutations are innocuous. However, some can lead to cellular damage, resulting in cancers and other conditions that impact normal functioning and decrease survival rates.
Dr. Alex Cagan, the study’s lead author, expressed surprise at discovering a similar pattern of genetic changes in animals as disparate as mice and tigers. He further explained that the most exhilarating aspect of the research was the finding that “lifespan is inversely proportional to the somatic mutation rate,” suggesting that somatic mutations may indeed play a role in aging.
Source: AWM