-
Asked by bethmillward to Paddy on 22 Jun 2011.
-
Paddy Brock answered on 22 Jun 2011:
Yes! They are carnivores and dogs and sea lios are closer to each other than either is to, say, cats. Have a look at this evolutionary tree: http://www.whozoo.org/mammals/Carnivores/carnivorephylogeny.htm.
My research is very related to your question; becasue sea lions are related to dogs they can catch some of the same diseases, which is bad news for the sea lions that live on the Galapagos. They have been living on the galapagos islands without humans or dogs for a few million years, so their immunity is not very good (because they haven’t been exposed to many diseases). However, now more and more humans are taking their dogs out to the Galapagos, the sea lions are in danger of catching diseases from the dogs.
-
Comments
Philip commented on :
Paddy will know more about this than me, but I want to use your question to illustrate how science is sometimes presented badly by the media. Paddy says dogs and sea lions are related, so they share a lot of DNA say 98% (humans / chimpanzees is the usual one) but that does not make them only 2% different. Humans, and I assume dogs and sea lions, share 50% of their DNA with celery, but that does not make us a salad vegetable. Its what that 2% or 50% difference in DNA codes for that counts.
Paddy commented on :
That’s a good point, simply comparing how much DNA two species have in common doesn’t tell you about how related they are or about how similar they are. Different bits of an organism’s genome (the total of all it’s DNA) change at different speeds in different species. The horseshoe crab (http://en.wikipedia.org/wiki/Horseshoe_crab), for example, has hardly changed for hundreds of millions of years, while monkeys and apes (incuding humans) have changed a huge amount during the last ten million years. Since it’s hard to say