Palynology and the Uses of Pollen
Solving crimes, dating artwork and imagining prehistoric landscapes are among the many uses of pollen in science.
Paleobotanists study pollen evidence to reconstruct former environments, thousands or even millions of years into the past.
Photo By Fotolia/Oleksiy Ilyashenko
The first time police used pollen to solve a crime was in Austria in 1959. A forensic scientist studying the mud on a murder suspect’s boot found what turned out to be a 20-million-year-old pollen grain from a hickory tree. That species no longer grew in Austria then. But investigators were able to locate a Miocene sediment outcrop on the Danube River, from which such a pollen grain could have become recycled into the environment.
“We know you killed him,” they told the murder suspect, in the best police procedural fashion, “and we know where.” Then they took him to the outcrop. The suspect was so unnerved that he led them straight to the victim’s grave.
Pollen analysis is still surprisingly rare in U.S. courtrooms, though such cases have made it commonplace in some other countries. Even in the “CSI” era, Americans tend not to think about it much, other than as a cause of hay fever. Certainly no one grows up wanting to be a pollen scientist. Even experts in the field have a curious tendency to explain that they came to pollen only by accident and somehow got hooked. It’s as if they fear that outsiders might otherwise think them congenitally dull.
Uses of Pollen
But for an impressive, if less sensational, variety of purposes other than forensics, pollen analysis has become a standard tool: Government agencies analyze the pollen content of fake Viagra and other prescription drugs to determine where they came from. Museums use pollen to authenticate paintings by master artists. Oil companies study fossil pollen to locate hydrocarbon deposits. Archaeologists study pollen to learn how ancient human communities used plants, and even the seasons at which they occupied a particular site. And paleobotanists study pollen evidence to reconstruct former environments, thousands or even millions of years into the past.
As scientific evidence, pollen has the advantage of being widely distributed, produced in vast quantities (researchers talk about the “pollen rain”), relatively easy for an expert to sort by species, and extraordinarily resistant to decay.
The science of interpreting this evidence is called palynology, from the Greek meaning “the study of scattered dust.” Ecologist Paul Sears popularized that name in the 1940s, because this branch of science also encompasses spores, cysts, and other microscopic residues of ferns, fungi, mosses, algae, and even some animals.
Actual pollen is merely the best-known subject of study, and the most spectacular. Under a microscope, the individual grains of pollen from different species can look like soccer balls, sponges, padded cushions, coffee beans, or burr balls from the sweetgum tree. Their surfaces are covered with intricate geometric patterns—all spikes, warts, and reticulations.