When people learn where Lucy was found in 1974 , there is a great temptation to make the assumption that the dessert conditions from which her bones were retrieved were the same conditions she lived in. That is a major mistake. Although we know of modern humans who successfully navigate living in the desert, and therefore cannot rule out that our ancestors may have had similar flexibility, the fact remains that Lucy and her kin lived in an environment that was very different. It appears that 3 million years ago, this part of Africa was a lot more forested that it is today. Also, compared to today, the area Lucy called home received about twice as much rainfall . I can hear you thinking: 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 . Animal remains are such a clue as they assist in the reconstruction of the environment. For example, when Baby Selam was found, remains of grazing antelopes were encountered as well . This indicates that there were grasslands in the region. The discovery of aquatic animals, such as the jaw of a crocodile , implies the presence of rivers or lakes in the same area at that time as well.
Another important pointer comes from pollen. We are all too familiar with pollen, as we suffer through allergy attacks every year. Pollen, the powder consisting of pollen grains, carry 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.
A preponderance of tree pollen during a certain time period would allow one to suggest that the area was forested at that time. With regard to the Hadar region, where both Lucy and baby Selam were discovered, the analysis of fossil pollen revealed that the region had an extensive herbaceous cover surrounding a paleolake . Moreover, the retrieval of pollen from various sedimentary layers dating back to between 3.4 million years ago to 2.95 million years ago, has shown how the climate changed over time. Initially, there were both evergreen and deciduous forests. Later this woodland environment changed into wet and dry grassland. Researchers concluded that “Hadar was located at the limit of a warm mixed forest biome adjacent to [a] xerophytic cool steppe along an escarpment .” In other words, it seems Lucy and her family would have been able to climb into trees if needed as well as step out onto a plain dotted with bushes.
Even with extensive datasets collected in the Hadar region, it is always good to remain skeptical and check that information against trends observed in the wider world. The shift from a predominantly forested environment to grasslands has been observed in data coming from other parts of Africa as well
Reconstructing ancient environments will never be as accurate as what we expect to hear from the weatherman (sic), yet these reconstructions provide us with a big picture that is sometimes quite different from what it is now. The forested environment in which Lucy once roamed compared to the present-day desert is a good case in point.