Compared to other animals, humans have a much longer lifespan. Dogs, cats, and even hamsters have significantly shorter lives. But have you ever wondered why humans can live until the age of 80 on average? Well, scientists might have finally found the answer to this age-old question.
The key to understanding this difference lies in something that humans and animals have in common. It seems that all mammal species, including humans, tend to experience a decline in their bodies and eventually die after accumulating a certain number of genetic mutations. This suggests that the accumulation of gene mutations might determine how long a creature lives on Earth.
In the past, scientists believed that the size of an animal was what determined its lifespan. For example, elephants and whales tend to live longer than rats and mice. However, a recent study suggests that it’s not the size of the animal, but rather the number of gene mutations it has accumulated over time that determines its lifespan.
This groundbreaking study was conducted by researchers at the Wellcome Sanger Institute in Cambridge, UK. They discovered that larger animals have the ability to slow down the rate of gene mutations, allowing them to live longer than smaller mammals. Animals with longer lifespans have developed mechanisms to minimize the damage caused by gene mutations that occur as they age.
One fascinating example is the five-inch naked mole rat, which can live for an impressive 25 years. Despite its small size, this species has the ability to minimize cell damage caused by gene mutations, leading to a longer lifespan. Surprisingly, the naked mole rat actually outlives the average giraffe, which only lives for around 24 years. When comparing the number of gene mutations, scientists found that both species had similar amounts. Giraffes experience an average of 99 gene mutations per year, while naked mole rats have around 93.
In contrast, mice, which have an average lifespan of only 3.7 years, experience a staggering 796 gene mutations per year. Humans, on the other hand, who live an average of 83 years, have a much lower rate of gene mutations at approximately 47 per year.
It’s important to note that many gene mutations are harmless. However, some can lead to cell damage and the development of conditions such as cancer, which can impair normal functioning and reduce an organism’s overall survival rate.
Dr. Alex Cagan, the first author of the study, expressed surprise at finding a similar pattern of genetic changes in animals as different from each other as a mouse and a tiger. He also highlighted the exciting discovery that lifespan is inversely proportional to the somatic mutation rate. This suggests that somatic mutations may play a role in the aging process.
The findings of this study shed light on the factors that contribute to the longevity of different mammal species, including humans. Understanding the relationship between gene mutations and lifespan can help scientists uncover potential interventions to prolong human life and improve overall health as we age.
