Busting Crime (And Climate Mysteries) with Algae
Image from Peter Siver)
Crime-fighting doesn't typically fall within a botanist's job description but, then again, Peter Siver is hardly your typical botanist, as Julie Wernau makes clear in her nice profile. Siver has spent his entire career studying diatoms and chrysophytes, microscopic photoautotrophs that are commonly found in oceans, lakes and other bodies of water. In the process, he has traveled around the world looking for clues about climate change events stretching back millions of years--and, occasionally, has helped solve the odd murder case.
Image from Brandon Mosley/Connecticut College
Where most police officers only see a fleck of mud on a discarded shoe, Siver finds a diverse microhabitat teeming with different types of diatoms. The mud he finds has a story to tell. Using only a minute amount, he is able to dig back hundreds of years to learn more about the environment from which it came. By determining which lake or river they originate from, Siver is able to provide vital clues that have helped crack some tough cases.
Of course, solving crimes is only tangentially related to Siver's main line of work, which consists of examining how water bodies have changed over time as a result of climate change and other natural processes and of tracing the evolutionary origins of his beloved diatoms.
The study of diatoms and other microorganisms is relevant here, because scientists like Siver can compare the morphology of extinct species found in old mud patches to existing ones to see if they share any similarities. This can tell us what type of climate prevailed in various regions millions of years ago.
For instance, a few months ago, Siver obtained a sample of mud from northern Canada that dated back 48 million years ago and discovered an organism identical to some that now live in tropical regions. As a result, he deduced that northern Canada, which is now a frigid tundra, was once balmy and tropical.
Last year, Siver discovered a new genus of diatom (he has discovered 60 new species over the past 20 years) that sheds light on the origin of the "raphe" -- a slit that appears along the long axis of pennate diatoms. (It may not sound that impressive to you and me but, according to Siver, the evolution of the raphe in diatoms is tantamount to the evolution of wings in a bird.)
For someone like me, who always tends to think of climate change research in terms of large-scale models, historical temperature pattern reconstructions and temperature measurements, it's nice to see a scientist whose work is both elegant and very informative (much more so than many studies you'll see these days).