Evolution Mini-exam Flashcards
65 mil yrs ago
Archonta
Small arboreal animals.
Nocturnal, large eyes, ate insects.
Radiated to bats, tree shrews, and primates.
65 mil yrs ago
Earliest primates
Arboreal and insect eating.
Prehensile - grasping hands and feet with opposable thumbs.
Finger nails, no claws.
Binocular vision - allows forward facing eyes and depth perception.
40 mil yrs ago
Primates split into Prosimians and Anthropoids.
40 mil yrs ago
Prosimians
Like a cross between a cat and squirrel.
Lived in N. America, Europe, Asia, and Africa. Few left today.
Ie. Tarsier of tropical Asia, Lemur of Madagascar.
40 mil yrs ago
Anthropoids
Higher primates.
Monkey, apes, humans.
Diurnal - active in the day. Eat fruit and leaves.
Larger brain. Extended care for offspring allows for longer brain development.
The group evolved in Africa to current day monkeys.
It’s unclear which was the first anthropoid. It could have been Eosimia or Catopithecus.
40 mil yrs ago
Anthropoids
Eosimia
45 mil yr old fossil found.
Lived 25 mil yrs after dinosaur extinction.
40 mil yrs ago
Anthropoids
Catopithecus
37 mil yr old Egyptian fossil found.
Lemur like primate.
Monkeys
New World Monkey
30 mil yrs ago some anthropoids migrated to South America.
Arboreal, flat nose, prehensile tail.
Ie. Golden Lion Tameron, Spider Monkey
Monkeys
Old World Monkey
25 mil yrs ago the anthropoids staying in Africa split into 2 groups: old world monkeys and hominoids.
O.W.M. - evolved separately from New World Monkeys for 30 mil yrs.
Ground and arboreal.
No prehensile tail.
Nose points down with close nostrils.
Some have sitting pads. Ie. Baboon.
Hominoids
Apes and humans.
Living apes - gibbons, orangutans, gorilla, chimp, baboon were common in Asia and Africa, rare today. Never were in North and South America.
Who was the first hominoid?
1932 - an 8 mil yr old jaw with teeth found in India. Named Ramapithecus after deity Rama. Never found this type in Africa.
1981 - more complete fossil found. Ramapithecus related to orangutan.
Which ape is our closest relative, according to DNA evidence?
See packet.
Human DNA vs chimp - 98.4% identical.
Human DNA vs gorilla - 97.7% identical BC gorillas split off before chimps.
Hominids
Are bipeda and walk upright.
Apes knuckle walk, monkey palm walk.
Laetoli, East Africa
69 hominid footprints found in volcanic ash.
3.7 mil yrs old.
Strong heel strike indicate bipedal, up right walking.
Big toe not splayed to the side as in an ape footprint.
Evolution
Charles Darwin
1871 published The Descent of Man
Based on comparative anatomy, development, and behavior.
He concluded humans descended from African apes, which are now extinct.
Climate change
5-10 mil yrs ago the world climate cooled.
African forest becomes a savanna and grassland.
Bipedal apes evolve:
Australopithecus - older version, smaller brain.
Homo - more modern type, larger brain.
1924 Australopithecus africanus
An odd rock was found in a mine.
2.8 mil yr old skull of a 5 yr old with milk teeth.
Some ape like features. Projecting face and small brain.
Some humans features - rounded jaw, foremen magnum on bottom of skull.
1938 Australopithecus robustus
A stockier version of africanus found in South Africa. It had massive teeth and jaws.
1959 Australopithecus boisei
Found in E. Africa by Mary Leakey. Named after Charles Boisei, who funded the dig.
Stockier the robustus.
2 mil yr old fossil nicknamed the Nutcracker Man bc of bony ridge on the chest of the head. It was an attachment site for jaw muscles.
1974 Australopithecus afarensis
Founded by Don Johnson in the Afar desert of Ethiopia. Most complete so far - 40%. 3 mil yr old called Lucy. Female pelvis. Bipedal leg bones. Projecting face of an ape. Chimp size brain 400cm3 (avg student brain 1300cm3)
1990 - 3 more individuals found. This is diverse grp bc hominid evolution began in many places.
1994 - almost complete skeleton found in Ethiopia. 4.4 mil yrs old. More ape like than Australopithecus. Called Ardipithecus ramidus. Afar language: Ardi - ground, rami - root
1995 - Australio anamensis. Ancestor to A. Afarenses. Intermediate between Australio and Arde.
Clads
Groups with traits in common to an ancestor
Phylogenic tree
Lumpers and splitters
Early homo
African origin. Many skeletons found in the last 30 yrs.
Homo habilis
Stone tools and a crushed skull found near A. boisei.
Reconstruction produces a 680cm3 skull. Larger than Australio of 400-550cm3.
Bc of tools, called habilis or handy man.
1986 - partial Skelton found. Arms were longer than the legs, like Australio.
Many researchers questioned if it was human.
Hmo habilis or homo rudolfenses
1972 Richard Leakey at Lake Rudoff in N. Kenya.
Found 1.9 mil yr old skull 750cm3.
Human, not Australio.
Some call it habilis, others rudolfenses.
Homo ergaster
Found by German worker. Homo skeleton - clearly not habilis or rudolfenses. Larger brain than rudolfenses. Modern human size teeth. Probably an ancestor to modern humans.
Homo erectus
First fossil looking truly human.
Homo erectus
Java Man
Long legs of an upright walker.
Large brain 1000cm3.
Old bones ~500,000 yrs old.
1969 nearly complete skull found.
Homo erectus
Peking Man
1920s in Dragon Bone Hill, a cave on a hill about 40 Km South of Peking China, now called Beijing.Bones similar to Java Man found. 14 skulls, crude tools, ashes of a camp fire.
1941 at the onset of WWII a trunk of fossils was lost. Plaster casts sent around the world for safe keeping. After the war, 40 fossils were found. 1043cm3 skull. ~5 ft tall, brow ridges, modern round jaw.
Homo migrates out of Africa
1976 complete erectus skull found in East Asia.
1.5 mil yrs old, older than Java or Peking Man.
This was the beginning of human expansion.
Life style of homo erectus
Social tribes or 20-25 people. Caves or crude wooden structures. Hunted large animals. Butchered them with flint and bone tools. Cooked over fires. Disappeared in Africa 500,000 yrs ago. Disappeared in Asia 250,000 yrs ago.
Modern human
Appeared in Africa 600,000 yrs ago. There could've been 3 original species: Homo heidlbugensis, Homo neanderthalensis, Homo sapiens. Or just Homo sapiens.
