CSI Microbiology: Germ Fingerprints Could Help Catch Criminals

Each of us is unique and special. So too are the bacterial communities infesting our grimy palms. As we move through the world, we deposit a potentially incriminating microbial film on everything we touch. Scientists at the University of Colorado at Boulder hope that our individual germ prints will one day be used to catch criminals. Their study, published yesterday in the Proceedings of the National Academy of Sciences, found that traces of bacterial DNA can be used to link people to objects they've touched, even hours after the fact:

Using powerful gene-sequencing techniques, the team swabbed bacterial DNA from individual keys on three personal computers and matched them up to bacteria on the fingertips of keyboard owners, comparing the results to swabs taken from other keyboards never touched by the subjects. The bacterial DNA from the keys matched much more closely to bacteria of keyboard owners than to bacterial samples taken from random fingertips and from other keyboards, Fierer said.

In a second test, the team swabbed nine keyboard mice that had not been touched in more than 12 hours and collected palm bacteria from the mouse owners. The team compared the similarity between the owner's palm bacteria and owner's mouse with 270 randomly selected bacterial samples from palms that had never touched the mouse. In all nine cases, the bacterial community on each mouse was much more similar to the owner's hand. [Science Daily]


Bacterial signatures can sometimes be recovered from surfaces where no DNA or fingerprints can be found.

The technology isn't ready for prime time yet. So far, the method has only proved 70% to 90% accurate. Much more testing will have to be done before this kind of evidence gets anywhere near a courtroom. But researchers are hopeful that the test will become more accurate as more powerful gene sequencing techniques are developed.

Previous research by the same team determined that each person has about 150 species of bacteria on their hands, but that any two people only have about 13% of their species in common. How's that for diversity?

Photo credit: Cropped from an image by estherase, licensed under Creative Commons.

Plants have awareness and intelligence, argue scientists

Research in plant neurobiology shows that plants have senses, intelligence and emotions.

Getty Images
Surprising Science
  • The field of plant neurobiology studies the complex behavior of plants.
  • Plants were found to have 15-20 senses, including many like humans.
  • Some argue that plants may have awareness and intelligence, while detractors persist.
Keep reading Show less

Human extinction! Don't panic; think about it like a philosopher.

Most people think human extinction would be bad. These people aren't philosophers.

Shutterstock
Politics & Current Affairs
  • A new opinion piece in The New York Times argues that humanity is so horrible to other forms of life that our extinction wouldn't be all that bad, morally speaking.
  • The author, Dr. Todd May, is a philosopher who is known for advising the writers of The Good Place.
  • The idea of human extinction is a big one, with lots of disagreement on its moral value.
Keep reading Show less

Space is dead: A challenge to the standard model of quantum mechanics

Since the idea of locality is dead, space itself may not be an aloof vacuum: Something welds things together, even at great distances.

Videos
  • Realists believe that there is an exactly understandable way the world is — one that describes processes independent of our intervention. Anti-realists, however, believe realism is too ambitious — too hard. They believe we pragmatically describe our interactions with nature — not truths that are independent of us.
  • In nature, properties of Particle B may depend on what we choose to measure or manipulate with Particle A, even at great distances.
  • In quantum mechanics, there is no explanation for this. "It just comes out that way," says Smolin. Realists struggle with this because it would imply certain things can travel faster than light, which still seems improbable.
Keep reading Show less