Final answer:
East Africa is rich in ancient human fossils due to favorable preservation conditions, such as sediment buildup in the Great Rift Valley, and the dedicated research of paleontologists like the Leakeys and Donald Johanson. Important finds like "Lucy" and varied genetic evidence contribute to our knowledge of human evolution.
Step-by-step explanation:
Why is East Africa so rich in ancient human fossils?
The richness of ancient human fossils in East Africa, particularly in the Great Rift Valley, can be attributed to several geological and environmental factors. The erosion patterns of the highlands have caused a buildup of sediments on the rift valley floor, which acts as a natural preservation layer for biological remains. This environment has been conducive to the preservation of both human and animal remains, evident in the discovery of the famous australopithecine nicknamed "Lucy" in 1974, among many other significant fossils. Additionally, numerous paleontologists, including Donald Johanson and Richard and Mary Leakey, have conducted extensive research in this region, uncovering remains of hominids dated to about 10 million years ago.
Other important hominin fossils discovered in East Africa include Paranthropus boisei, identified by Mary and Louis Leakey. This region also provides valuable genetic diversity information, where the wider genetic variation in the human population in Africa compared to the rest of the world is reflected in the fossil records. The fossils unearthed in East Africa, such as Lucy (Australopithecus afarensis) and Homo naledi, contribute significantly to our understanding of human evolution and origins.