Question: why are dog years so long

Andrew Jackson answered on 11 Nov 2012:

hi,

What a great time to ask me this question! I have been thinking lost about this very question with my phd student and a friend and scientist in glasgow who trained me in my phd about 6 years ago. We have just finished writing a science paper about something very similar and are waiting to hear back from the journal if they will publish it or if they want us to make some changes.

It turns out that generally, big animals live longer and see the world change much slower than small animals that live fast and die young. Smaller animals can see very quick changes in their world because their eyes and brains are wired to react to sudden changes. Larger animals instead miss very quick events and would not see small fast moving animals hardly at all.

We think this is because small animals can move quickly themselves, and so need to perceive the world around them quickly too. Big animals, like whales, dont need to see or react to very quick events because they just dont care – anything moving fast is probably small and is no threat to them and they couldn’t catch it to eat either so they just move around relatively slowly.

So, dogs are smaller than humans, so they see the world change around them much fast, and they also tend to live their lives quicker and they die younger than us. Its not always obvious though as some animals seem to be able to cheat when it comes to their life span. Many parrots can live to 40 years and bats live far far longer than anything else of their size.

I have just started a new project with several friends of mine in work because we asked the question: what makes some animals live longer than others? We are busy collecting information on all sorts of different animals, and in a few weeks I should have some brand new answers for you!

cheers
andrew