Did you know that compared to many other mammals, humans have a longer lifespan? Dogs live for about twelve years, cats can reach fifteen or more years, while hamsters only live a few years. Blue whales, the largest mammals on Earth, can live up to one hundred and ten years, making them the longest-living mammal documented.
So, what sets humans apart and allows us to reach the age of eighty on average? Scientists have finally found an answer to this age-old question, and it has to do with our genes.
For years, researchers believed that an animal’s size determined its lifespan. However, a new study from the Wellcome Sanger Institute in Cambridge, UK has shown that it’s not the size but the number of gene mutations that influence an animal’s lifespan.
The study revealed that larger animals have the ability to slow down the rate of gene mutations, which allows them to live longer than smaller mammals. Animals that live longer can reduce the damage caused by gene mutations over time, extending their lifespan.
One fascinating example is the five-inch naked mole rat, which can live for twenty-five years despite its small size. This species has a unique ability to minimize the damage caused by gene mutations, resulting in a much longer lifespan compared to its size. In fact, the naked mole-rat lives longer than a giraffe, which has an average lifespan of twenty-four years. Surprisingly, both species have a similar number of gene mutations per year, with the giraffe having approximately ninety-nine and the naked mole-rat having about ninety-three.
In contrast, mice, which only live for about 3.7 years, have a significantly higher number of gene mutations per year at approximately 796. Humans, with an average lifespan of eighty-three years, have far fewer gene mutations per year, around forty-seven.
While some gene mutations are harmless, others can lead to cell damage and the development of conditions like cancer, impairing normal bodily functions and reducing the chances of survival.
Dr. Alex Cagan, the first author of the study, expressed their surprise at finding a similar pattern of genetic changes in such different animals as mice and tigers. The most exciting aspect of the study, however, was the discovery that lifespan is inversely proportional to the rate of somatic mutations. This suggests that somatic mutations may play a role in the aging process.
This groundbreaking research sheds light on why humans live longer than many other mammals and provides insight into the role of gene mutations in determining lifespan. So, the next time you wonder why humans often live until the age of eighty, remember that it’s all about the genes.
