4.4 - Fossil Evidence for Human Evolution Flashcards
What does fossil evidence show about the development of organisms?
Fossil evidence shows that developments in organisms arose slowly, as carbon dating and related techniques help estimate when a fossil was formed.
Who is Ardi and what is significant about her?
Ardi, or Ardipithecus ramidus, is the oldest known human ancestor, estimated to have lived 4.4 million years ago. Her fossilized skeleton contains humanoid features and resembles an ape, indicating she is phenotypically between the two. The presence of this intermediate organism supports the idea that natural selection and evolution occurred gradually.
What does the bone structure in Ardi’s feet suggest?
The bone structure in Ardi’s feet is different from that of chimpanzees, suggesting that humans and chimpanzees evolved separately.
What is Lucy and what does her fossilized skeleton indicate?
Lucy is a fossilized skeleton dating from 3.2 million years ago. Her bone structure suggests she walked in an upright, human-like position, but she had a small, chimp-like skull and brain, representing another intermediate between apes and early humans.
What contributions did Louis and Mary Leakey make to the theory of natural selection?
Louis and Mary Leakey discovered fossils in the 1950s that supported the theory of natural selection, including an early fossil with remnants of stone tools and Homo habilis, an important early human species.
