by Yolanda Ridge
In crime shows the first thing detectives look for is fingerprints. I’m sure you know why —because every person has a unique pattern on the tips of their fingers. This means anything touched by the criminal could help to identify them.
Smart criminals wear gloves for exactly this reason. To stay one step
ahead, detectives and scientists figured out how to look for
something else that’s unique — DNA fingerprints.
What is DNA? It’s the alphabet used to write the instruction manual on how all living things develop, grow and function. A copy of this instruction manual is contained in every single cell of our body. Which means that if a criminal leaves a piece of hair of a speck of spit at the scene of the crime, scientists can examine the DNA within the cells to try and identify a suspect.
DNA fingerprinting has been available for a while but now there’s something new on the scene — environmental DNA. Better known as eDNA, environmental DNA is DNA that’s been shed by an organism into the environment. And it’s found almost everywhere — water, soil, ice and even air.
Environmental DNA is not being used to fight crime — at least not yet. But over the past ten years it’s been used to do some cool stuff including:
verify a new whale species in Mexico
monitor endangered fish species like the dwarf Galactus in Australia
determine whether there’s enough food for tigers in Bhutan
research biodiversity and native species in areas like Columbia
track polar bear populations and movement in the arctic
detect invasive species such as Asian carp, American bullfrogs and New Zealand mudsnails
detect microbes dangerous to plant, animal and human health in waterways around the world
More recently, scientists showed they could vacuum eDNA directly from the sky. To prove it, two different research groups identified DNA from animals at a nearby zoo in samples of the air.
To find out more about eDNA, check out these YouTube videos:
EnviroDNA (Australia): https://www.youtube.com/watch?v=TQdTV1rAlWY
From the World Wildlife Fund: https://www.youtube.com/watch?v=4YXfZvEvUgc
And keep following science blogs like this to learn more about how eDNA gets used in the future. It’s coming soon to a crime scene near you (but hopefully not too near you!).
Yolanda Ridge is a middle grade author, science writer and knowledge translation co-ordinator from Rossland, BC. Visit her website at www.yolandaridge.com to find out more.
Fingerprint image by Stux from pixabay.com
DNA by Jerome Walker from Wikimedia Commons
eDNA image from Biological Conservation via ScienceDirect
Cloud DNA by Andrew Brumagen via Freethink