Corpses, Cadaver bugs and Climate Change

When I started taking classes in Biology, I had my eyes on becoming a doctor. I signed up for all of the appropriate intro classes, started researching medical programs and considered different volunteer opportunities to get into medical establishments. Then I got to Anatomy and Physiology, where we had to dissect all sorts of animals: sheep brains, eye balls, rats and even cats. Yes cute, adorable, cuddly, preserved stray cats.

Now I wasn’t really bothered by the other animals, but being a cat lover, having to peel back the fur and cut in was a bit much for me. Ever the learner, though, I was willing to make the effort – FOR SCIENCE! Everything was fine, up until the third day of dissection when my lab partner, while shaking the half-dissected cat out of the plastic bag we were storing it in, accidentally splashed me with cat juice. Actually splashed is somewhat inaccurate. Showered seems more appropriate. That was the very end of my medical career.

But some people are not so easily deterred from medical science and even find far more gruesome encounters with Biology all the more interesting. This is never more clear than for those who study forensic entomology – you know, like CSI, but without Hollywood plastic surgery and with loads of rotting things and things that like to eat rotting things.

If you’ve spent any time watching the Discovery channel late at night, you know that one of the ways to tell how old a cadaver is – aka when did that person die? – is to look at the fauna (insects!) Turns out that we actually know a lot about the insects that develop on corpses, their lifecycle and how long it takes for them to grow under different temperatures. So if you find a black soldier fly of a specific size, you could guess how long it’s been there and as a result, how long the corpse has been sitting around. Or lying around. Or whatever it is corpses do. Rot?

From reading my blog, you know that climate change will affect all sorts of biological systems. Now picture, without vomiting, a dead body lying outside in October, which it is unseasonably warm. Would you expect to have the same insects infesting? Would you think that perhaps if it was warmer they might develop faster, altering the estimated time since hatching and therefore time since cadaver death? Could other insects that are commonly found further south or at lower elevations suddenly be found in your cadaver?

Turns out changes in the cadaver fauna are already starting to be seen in both Europe and the US, as these insects are starting to move further north (1, 2, 3, 4). This is problematic if you are a forensic entomologist, because you can no longer use these insects as indications of where the body started its decomposition (ok, this might shock you, but people sometimes move dead bodies). Also, some larvae at certain stages move away from eating flesh and start grazing on the other cadaver-eating insects. If they are particularly voracious, they may completely clear the body of these other insects making it more difficult to identify when the person died. Grossed out yet?

So not only is climate change going to affect us in our lives, but it will follow us into our deaths. Let’s just hope it doesn’t find a way to mess up the afterlife. I have big plans to annoy climate deniers when I’m a ghost: making the walls bleed crude oil, leaving traces of the famous CO2 hockey stick in the mirror and moaning “Al Gore is your earth mother” in the middle of the night. And also switching their regular coffee for decaf.

Hey, what is death if you can’t have a little fun?

Happy Halloween!

Further Reading:
(1) The blowfly Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae) as a new forensic indicator in Central Europe
(2) Current Concepts in Forensic Entomology
(3) Records of Chrysomya albiceps in Northern Italy: an ecological and forensic perspective
(4) Forensic entomology and climatic change

Minda Berbeco has a PhD in Biology from Tufts University and is a science writer in the Bay area. She is impressed if you were able to make it to the end of this blog post without being grossed out. As a reward, she would like to share with you her favorite insect inspired video. Not gross. In fact delightful!

button print blu20 Corpses, Cadaver bugs and Climate Change
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