SCIENCE

Two lower jawbones point to East Africa as the birthplace of our evolutionary lineage. One jaw is a new discovery, while one was discovered by the Leakey family 50 years ago. (Nat Geo News)

Read our interviews with Meave and Louise Leakey to understand the evolving life of a paleoanthropologist.

Teachers, scroll down for a quick list of key resources in our Teachers’ Toolkit.

Discussion Ideas

• Read through the Nat Geo News article on the new fossil discoveries in East Africa. Why is LD 350-1, the new fossil discovery, described as a “transition” form?
  • LD 350-1 has aspects of both earlier and younger hominin fossils. Like older fossils, LD 350-1 has a receding chin line. Like younger fossils, LD 350-1 has slim molars, unique pattern of tooth cusps, and a similarly shaped mandible.
  • “The chin looks backwards in time. But the shape of the teeth looks forward,” says Bill Kimbel, director of the Institute of Human Origins, who co-led the analysis of the new specimen.

• Why aren’t all scientists convinced LD 350-1 points to East African origins for human evolution?
  • The fossil record is faaaaaar from complete! There is a lot left to be discovered. (Get digging!) “You could put . . . all [hominin fossils dating from 2-3 million years ago] into a small shoe box and still have room for a good pair of shoes,” says Kimbel.

• Where else might Homo species have originated?
  • South Africa. Many researchers think that “the best candidate for our genus’s immediate ancestor is a South African australopithecine, Australopithecus sediba.”

• Who is Lucy?
  • Lucy is the nickname of the Australopithecus aferensis specimen AL 288-1, discovered in 1974 in Hadar, Ethiopia. Lucy’s skeleton is much older and much more complete than LD 350-1, the newly discovered hominin jawbone. Read more about Lucy’s discovery here.

• Who is Handy Man? How did he earn that nickname?
  • Handy Man is the nickname of the first specimen of Homo habilis, an early ancestor much younger (by more than a million years) than Lucy and her A. aferensis pals.
  • Handy Man earned his nickname because he was found with sediments that also contained the oldest stone tools discovered at that time. (Older tools have since been found.)

• How does LD 350-1 link Lucy and Handy Man?
  • It may not! The fossil record is wildly incomplete.
  • Remember, LD 350-1 is a “transitional” fossil, younger than Lucy but older than Handy Man. LD 350-1 “has turned up as if ‘on request,’ suggesting a plausible evolutionary link between Australopithecus afarensis and Homo habilis,” says Fred Spoor of University College, London and the Max Planck Institute for Evolutionary Anthropology.

TEACHERS’ TOOLKIT

Nat Geo: Oldest Human Fossil Found, Redrawing Family Tree

Nat Geo: Real-World Geography: Dr. Meave Leakey

Nat Geo: Real-World Geography: Dr. Louise Leakey

African Fossils (find your favorite and examine it just like a paleontologist!)

(extra credit) Science: Early Homo at 2.8 Ma from Ledi-Geraru, Afar, Ethiopia (warning: behind a paywall)

(extra credit) Nature: Reconstructed Homo habilis type OH 7 suggests deep-rooted species diversity in early Homo