Fossil pollen dating
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.Their surfaces are covered with intricate geometric patterns—all spikes, warts, and reticulations.These structures “are very resistant to most biological forms of attack,” says Andrew Leslie, a Yale postdoc in paleobotany.What studying pollen gives scientists, in other words, is the means to do what the poet William Blake once imagined: To see a world in a grain of sand And a heaven in a wild flower Hold infinity in the palm of your hand And eternity in an hour.Add to that the ability to solve the occasional murder and palynology begins to sound like the kind of career a kid could grow up dreaming about. Excerpted from Environment Yale, an online magazine with a mission to reflect the intellectual vitality of the faculty, students, and alumni of the Yale School of Forestry & Environmental Studies.
But Cannabis diverged from Humulus around 28 million years ago, suggesting that it might have originated somewhere else, the study authors wrote in the new study.
Back in the laboratory, each sample goes through repeated hydrochloric acid baths, which destroy everything except the almost immortal exine.
The palynologist then puts the material on a microscope slide to determine how many species are present (worldwide almost a half-million species make pollen) and calculate the proportion of different species.
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.