The ageing process is very important in biomedical and ecological research. The bowhead whale can live up to 268 years, according to the clock. Previous research has suggested that it is controlled by genes but so far, no gene variants have been found that account for these differences.
Lifespans among vertebrates varies greatly. In the past 200 years, the average life expectancy of humans has more than doubled.
Understanding the pure lifespan is essential for conservation, biosecurity and wildlife administration, mentioned the researchers, and gives a extra correct method of calculating lifespan than earlier strategies that concerned observing how lengthy animals reside within the wild. Till now it has been troublesome to estimate lifespan for many wild animals, notably long-living species of marine mammals and fish'. "In addition, it can also be used to determine the catch limits in fisheries".
The CSIRO group took genomes of animals with identified lifespans from public databases resembling NCBI Genomes and the Animal Ageing and Longevity Database. Most estimates come from a small number of individuals living in captivity whose ages at death were known. The clock determined the tortoise's maximum lifespan is 120 years.
"DNA methylation does not change a gene's sequence but helps control whether and when it is switched on". Other researchers have shown that DNA methylation in specific genes is associated with the maximum lifespan of some mammals such as primates.
"Our method for estimating maximum natural lifespan is based on DNA. If a species' genome sequence is known, we can estimate its lifespan", Dr Mayne said. We then compared these genomes to another database of known animal lifespans.
Scientists have calculated the lifespans of extinct animals, including ancient humans, from the DNA they left behind. This method also lets us estimate the lifespans of long-lived and extinct species.
The discovery has revealed the lifespans of extinct species such as woolly mammoths and Neanderthals.
The bowhead whale could be the longest-lived mammal, reaching more than 250 years of age, they said. This estimate is 57 years higher than the oldest individual that has been found, so they may have a much longer lifespan than previously thought.
To estimate lifespan for the extinct woolly mammoth, the researchers worked with a genome assembled from the genome of the modern African elephant, which lives for 65 years. The last member of this species, Lonesome George, died in 2012 at age 112.
They screened 42 chosen genes for CpG websites, quick items of DNA with a density that correlates with lifespan in vertebrates.
"We estimated that Denisovans and Neanderthals both had a lifespan of 37.8 years". This has been extended over the centuries by changes in lifestyle and more recently by advances in medicine.