How Do We Know: Ancient Environments
Lucy’s remains were found in a desert environment. However, if Lucy could come back today, she would not recognize the place she once called home. It appears that 3 million years ago, this part of Africa was a lot more forested that it is today. That is interesting, but how do we know this?
Reconstructing an ancient environment, like the work of a good detective, relies on looking for as many clues as possible. One of these clues is pollen. We are all too familiar with pollen, as we suffer through allergy attacks every year. Pollen, the powder consisting of pollen grains, carries the male sex cells of seed plants. They are virtually indestructible and easily identifiable under a microscope. Soil samples taken from the walls of excavation trenches are analyzed for their pollen content. This allows us to identify what plants lived in the area and how they fared over time. Plants are good indicators of environmental conditions; having a preponderance of tree pollen during a certain time period would allow one to suggest that the area was forested at that time.
Fossilized animal remains can also help reconstruct the environment. Encountering the remains of tree-dwelling animals is an indication of the presence of a tree environment. Fish bones, or the remains of hippos and crocodiles, would imply a lake or river environment.
Fluctuations in temperatures over long periods of time can be retraced using oxygen isotope analysis in ice samples. Tree ring data can also tell us about similar changes in temperatures and rainfall.
Reconstructing ancient environments will never be as accurate as what we expect to hear from the weatherman, yet these reconstructions provide us with a big picture that is sometimes quite different from what we might see now. The forested environment in which Lucy once roamed compared to the region's present-day desert is a good case in point.
![]()
|
One Hermann Circle Drive
