Human Evolution Part I - Primates. “To understand the story of evolution, we must understand both our ancestors and our relationships to our closest living kin.” (Holt - Modern Biology – ch 17). Humans are members of the mammalian order of Primates. “As you can see, many
we must understand both our ancestors
and our relationships to our closest
living kin.” (Holt - Modern Biology – ch 17)
order of Primates.
“As you can see, many
of our behaviors and
similar to those of other
primates, and some
are uniquely human.”
aye aye found in Madagascar
The group consists of tarsiers and the anthropoids, the humanlike primates.
Anthropoids include hominids and Old and New World monkeys. In turn hominids include apes and humans.
orangutans, chimpanzees, gorillas & humans)
Phylum – Chordata
Subphylum – Vertebrata
Class – Mammalia
Order - Primate
(prosimian primates – resemble early forms such as lemurs, & tarsiers.)
and toes, and most have
flattened nails rather than
claws. (In some species,
the feet are
vision. They have front-facing eyes, and
overlapping fields of vision.
useful trait for an animal that moves by
swinging or jumping from branch to
branch. (An adaptation for life in the
developed collar bone, rotating shoulder
joints, and partially rotating elbow joints.
which results in increased precision of
opposable big toe.
formula, or number and arrangement
anthropoids have a large brain
relative to their body size.
the most closely related to man. Their DNA has a high
degree of similarity. “Now that scientists have decoded
the chimpanzee genome. We know that 98% of our
DNA is the same.”
This similarly suggests
That humans and
chimpanzees may have
shared an ancestor
less than 6 million
ability to walk on two legs. This is a uniquely
human trait among mammals. Chimps can only
walk in a bipedal fashion for a short period of time.
during walking. The human spine has two curves resulting
in an = “S” shape that allows for upright posture.
(compared to the “C” shape in chimps)
chimpanzee body than in a human body. The chimp has
more weight in the upper trunk,
whereas humans have
more weight in the
Pelvic shape, muscle shape
and attachment, and the
fact that human knees are
straight rather than bent,
are factors that enable
humans, and not chimps,
the ability of prolonged
which are aligned with each other. This may
be seen as an additional bipedal adaptation.
The human jaw is more rounded than the U-
shaped ape jaw. It does not protrude as an ape’s jaw.
resulted in a more vertical face than in apes.
The human brain has extensive areas
devoted to the production and
understanding of speech.