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| © Provided by Associated Newspapers Limited Researchers were able to calculate a link between the DNA clocks of humans and dogs to create a formula that can be used to give a dog's age in 'human years' |
Calculating the age of a dog in human years is much more complicated than first thought, scientists claim.
The
idea that a dog's age in human years is its age times seven 'is a
myth', according to researchers from the University of California.
They
have created a new formula for calculating the relative age of a dog
compared to a human, based on the rate that molecules are added to DNA.
The
team, led by geneticist Tina Wang, say it isn't easy to come up with a
true comparison between the relative age of a dog and a human as they
reach maturity at different rates and different dog breeds have
different life spans.
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| © Provided by Associated Newspapers Limited The team studied the DNA of multiple dog breeds and humans at various stages of their life to find a link in their DNA clocks |
The formula looks
at changes to DNA over time, specifically to the 'methyl groups', which
are molecules that add themselves to DNA at a consistent rate.
They can be used to measure the age in humans and dogs in a process known as the epigenetic clock.
Dog
lifespans vary from 6-7 years for larger breed to anything up to 18
years for smaller dogs but, despite the lifespan difference, they have a
different physiological trajectory.
They found similarities in the timing of major milestones between dogs and humans.
The similarities were particularly strong when similar age dogs and humans were compared.
The new formula, based on the epigenetic
clock involves finding the natural logarithm of a dogs age, multiplying
it by 16 and then adding 31 to the total.
Using this formula an 18 year old dog would be 77 and a 2 year old dog would 42 in 'human years'.
The
team did find that there were periods in the life of dogs where the
clocks didn't match humans, including during puberty as they mature
earlier in their lifecycle than humans.
Researchers say even with the issues around puberty, their formula is still more accurate than the 'dog age plus seven myth'.
This research has been published on BioRxiv.
HOW DO YOU CALCULATE THE AGE OF YOUR DOG IN 'HUMAN YEARS'?
human_age = 16ln(dog_age) + 31.
In simpler terms Human age is the same as 16 times the natural logarithm of dog age plus 31.
To get to the age of your dog in 'human years' you multiple the the natural logarithm of your dogs real age by 16 then add 31.
You can use the 'ln' button on a calculator to get the natural logarithm of your dogs age.
You can also use an online tool to calculate the natural logarithm. Just enter the dog age to get the correct value.
You then multiply that figure by 16 and add 31 to the total.
EXAMPLE
If your dog is 7 then its natural logarithm number will be 1.9459.
You times this by 16 to get to 31 when rounded down.
Then add 31 to find out your 7 year old dog is 62 in 'human years'.
