Washington, United States:
A well-known “paw rule” says that you can tell how old your dog is in human terms by multiplying his age in years by seven.
But in fact, the actual ratio changes over time, the National Institutes of Health (NIH) in the United States said on Thursday, following a study of the life history of dog genomes.
Dogs, humans and in fact all mammals experience the same development chronology: birth, infancy, youth, puberty, adulthood and death.
Scientists have identified chemical marks on DNA that correspond to these different stages, a field of study called epigenetics.
The field is well established for humans, and some commercial companies allow you to send a DNA sample to determine your biological age by reading your “epigenetic clock”.
Molecules called methyl groups attach to a particular region of DNA, switching them to the “off” position and marking the start of the next stage in life.
Trey Ideker of the University of San Diego, who was the main author of the study published in Cell Systems, compared these models to wrinkles on the genome.
“I tend to think of it like when you look at someone’s face and guess their age based on their wrinkles, gray hair and other characteristics,” he said.
“These are just similar characteristics at the molecular level.”
– More complex formula –
Ideker and his colleagues studied the methylation patterns of 104 Labrador retrievers, whose ages ranged from a few weeks to 16 years. These were then compared to human methylation models.
Scientists have been able to devise a more complex formula that better matches the stages of canine-human life – but you will need a scientific calculator to understand it.
The formula is “human age = 16 * ln (age of dog) + 31”, and you can also use Google to try it out for yourself (remember it’s l for “log” then n for ” natural “, all lowercase).
So if your dog is two years old, type, without quotes, “16 * ln (2) + 31” and press Enter to reveal “42”.
Based on this formula, an eight-week-old puppy is roughly equal to a nine-month-old human baby – both being at the stage where they are developing teeth.
The average lifespan of Labradors is 12 years, which also roughly corresponds to a human life expectancy of 70 years.
“I like to take my dogs to the races, so I’m a little bit more sympathetic to the 6 year old kid now,” said Ideker, because his pet is the human equivalent of 60 years old under the new formula.
NIH scientist Elaine Ostrander, who co-authored the study, said the new formula was developed with Labradors in mind, but more research could include long-lived breeds – which are generally smaller – and short-lived breeds, which are larger.
These clocks will improve our understanding of interspecies aging and help veterinarians in their clinical practice, the team said.
(With the exception of the title, this story was not edited by GalacticGaming staff and is published from a syndicated feed.)