野生动物会过敏吗?

Adam Murphy put this question to Andy Flies, a wild immunologist from the University of Tasmania.

Andy - The short answer is yes. Animals do get allergies but not at the same rate as humans. However the distinction of “wild animals” and not just “animals” makes the question much more interesting to this wild immunologist. The number of documented cases of allergies in wild animals is tiny compared to the number of allergy cases in humans and domestic animals. This could be a sampling bias because domestic animals are regularly observed by their owners. Thus allergies are more likely to get noticed and reported than for an elusive wildcat.

Adam - I think the sheer number of pets sneezing videos on the Internet probably backs that up a little.

Andy - Alternatively, natural selection could make it difficult for animals with allergies to survive and reproduce. For example, think of a leopard stalking its prey only to sneeze when it gets close. From a scientific point of view, the higher rate of allergies in captive animals than in wild animals is a fascinating parallel to the rise of allergies in industrialised human society. There are many hypotheses as to why there has been an increase in allergies in humans in the past century. But most of them revolve around humans being disconnected from the environment in which we evolved. As human society has urbanized, we have become less likely to be infected with the microbes and parasites with which we co-evolved. The immune system needs to be “trained” by early and continuous exposure to microbes and parasites for proper development. Without this “training” the immune system can end up attacking the wrong targets like harmless pollen. Giving your dog bottled water might send it down the same allergy prone path that many humans have trodden.

Adam - Thank you Andy for helping sniff out an answer to that question. Next week, we're leaving allergies (and the whole planet) behind as we go to the moon, to answer this question from Chad.

Chad - Is it possible to terraform the moon so humans could live there long term?