human evolution. mammal characteristics produce milk for young hair differentiated teeth embryos...
TRANSCRIPT
Human Evolution
Mammal Characteristics
• Produce milk for young• Hair• Differentiated teeth• Embryos develop inside and gain nutrients
from the mother (placentals)
Primates
• Order of animals in class Mammalia• 3 main groups: lemurs, tarsiers, and
anthropoids (monkeys, apes and humans)
Primate Characteristics• Open shoulder structure• Legs and feet designed to bear majority of the
individual’s weight
• Well developed fingers• Fingernails and Toenails (not claws)• Opposable thumbs
Continued• Hip and shoulder joints allow a wide range of
motion• Eyes directed forwards– Binocular vision = both eyes view the same objects
simultaneously with slightly different angles
• Large and complex brains• Omnivorous• One offspring at a time
What makes humans unique from other primates?
• Larger and more complex brain• Capable of language• Completely bipedal• Hands are better adapted for precise movement• Manufacture and use complex tools
Where did we come from?• Homo sapiens = only species of human that still
exists– 20 extinct species that are more closely related to
humans than chimps (hominims)
• Fossil records help us study our ancestors– Focus on pelvis, backbone, skull, jaws and teeth
• Molecular comparisons determine relatedness– Chimpanzees = closest living relative
Relatives• Hominids– Bipedal, human-like animals that belong to the same family
as modern humans– Appeared approx. 4 million years ago– 2 genera – Homo and Australopithecus (Lucy)– 2.5 million years ago hominids began to use tools– 1.5 million years ago hominids became more widely
distributed throughout the world (Homo erectus)– 160,000 years ago = early modern humans eventually lead to
Homo sapiens– Current debate over modern human lineage
• Not a linear progression but a branching phylogeny