SBI3U
3 Physical Characteristics
1. very large brain to body ratio
2. hands are capable of fine manipulation
and coordination
3. walk upright (bipedal), hands are free to
use tools
Ability to perform complex reasoning, exceptional
ability to learn, make use of sophisticated tools
and communicate using complex language.
Hominids
Hominoids
• Humans did not evolve FROM apes
• Rather, we share a COMMON ANCESTOR
• Humans and chimpanzees share 98.8% of their
DNA
• The most recent common ancestor we share with
chimps lived in Africa more than 6 million years
ago
• Hominids are all species descended from the
most recent common ancestor of
chimpanzees and humans that are on the
human side of the lineage
• The sequence of steps in the evolution of humans
• Between 6 and 7 million years ago a human ancestor
was walking upright occasionally
• First evidence of stone tool use by Australopithecus
afarensis date to 3.4 million years ago
• The first members of our own genus, Homo habilis
evolved 2 million years ago
• Homo habilis, the handy man, built stone axes and large
cutting tools
• Hunting tools allowed hominids to increase the amount
of meat in their diet, providing a rich source of protein
and fat
• By this time, hominid brains were significantly larger
than the chimpanzee-sized brains of australopithecines
• Hominid brain size increased relatively rapidly
from about 800 000 years ago to 200 000 years
ago
– Homo neanderthalensis and Homo sapiens evolved
during this time
• The first modern humans had evolved by about
100 000 years ago in East Africa
• All early hominids evolved and lived in Africa
• The first species to spread beyond Africa was Homo
erectus, about 1.9 million years ago, and survived
throughout Eurasia until at least 100 000 years ago
• 500 000 to 300 000 years ago Homo neanderthalensis
left Africa and populated parts of Europe
• After the earliest humans evolved they began to
spread out of Africa into Eurasia and eventually
reached the Americas
• Humans and chimpanzees are so similar
genetically, but are dramatically different
culturally
• Human culture is so rich and diverse:
– Over 6000 languages
– Countless artistic endeavors in music, dance and fine
arts
– Admire and cherish the talents of others
– Societies have different rituals, customs and beliefs
• Our ancestors lived as hunter-gatherers for
300 000 generations
• In the last 1000 generations or less humans
have domesticated plants and animals,
developed agriculture and begun to live in
large population centres
• Only during the last 10 generations has our
population skyrocketed
• Genetic comparisons
conclusively show that, from a
biological perspective, ‘races’
do not exist
• Traits we associate with races,
mostly skin colour, are visibly
obvious but genetically
minimal.
• More diversity within ‘races’
than there is between ‘races’