2 - Emergence of Primates & Evolution of Humans

Question 1

emergence of primates

Answer 1

around 65 mya

Question 2

common features of primates

Answer 2

grasping hands and feet
nails not claws
sensitive finger tips
large brains relative to body size
forward facing eyes, stereoscopic vision, colour vision
rotating forearm (open door, throwing ball)
generalized definition (not specialized for a specific type of food)
less reliance on sense of smell, more on vision
expansion/increased complexity of the brain

Question 3

phylogeny

Answer 3

the evolutionary history of a species

Question 4

purgatorius

Answer 4

considered to represent the earliest primate; teeth have characteristics of primates

Question 5

aegyptaphithecus

Answer 5

slow moving, arboreal quadruped, 36-24 mya

Question 6

miocene epoch 23

Answer 6

“the golden age of hominoids”, 5 mya, thousands of homonoid fossils from sites in Africa, Asia, and Europe; during end of miocene epoch, we see first upright walkers; most of the miocene apes have died out; sivapithecus is the only ape of the age that resembles modern age (orangutangs, 12 mya)

Question 7

hominids

Answer 7

creatures believe to be in the direct human line

Question 8

bipedalism

Answer 8

defining characteristic of hominids

Question 9

bipedalism: vertebral column

Answer 9

human spines are S shaped, apes have c shaped spines; S shapes brings centre of gravity back over hips; weight increases as you go down a biped’s spine (the vertebrae also get bigger)

Question 10

bipedalism: foramen magnum

Answer 10

the hole in the occipital bone where spinal chord attaches to brain; human’s faramen magnum is at bottom (vs back) of skin

Question 11

bipedalism: pelvis

Answer 11

2 innominate bones consisting of illium (hip bones), ischium (seat), pubis; human illums are shorter and broader to support organs pulled down by gravity and have muscles that help them walk

Question 12

bipedalism: leg

Answer 12

femur tapers inwards toward knee to bring feet into centre of gravity

Question 13

bipedalism: foot

Answer 13

main propulsal mechanism are toes, big toe is shorter, broader, and aligned with other toes
arches in feet
toe/foot bones are more tightly bound by ligaments

Question 14

Advantages of bipedalism

Answer 14

ability to see great distance
ability to provide food to others
adaption to living in tall grasses (when bipedalism emerged, forests where dwindling and replaced with grassland/savannah)
regulating heat
more effective scavenging (can gather food and take it away with)

Question 15

The upright provider

Answer 15

Owen Lovejoy
can bring food back to camp because their hands aren’t needed for locomotion, monogamy is big factor, the male would have exclusive rights to male in exchange for the male looking after female and offspring, very little evidence for ability to hunt by early bipeds

Question 16

The upright scavenger

Answer 16

Pat Shipman

Recognized animal teeth marks under tool marks on meat remains, suggested bipeds were scavengers

Question 17

The efficient Walker

Answer 17

Human locomotion is more energy efficient than chimp locomotion, 25% of energy to walk on 2 legs

Question 18

The endurance runner

Answer 18

the shape of pelvis and attatchment of gluteal muscles keep humans upright, the articular surfaces are very large in humans (impact of running can be absorbed over larger area), these changes are seen more in later hominids

Question 19

early hominids

Answer 19

emerged 7mya, most sites are around eastern africa

Question 20

sahebanthropas tchademsis

Answer 20

aka Toumai, North Central African, Chad
Found in 2001, aprox 7 mill yrs old, nearly complete cranium
Cranial capacity of 360-370 cubic centimetres, about the same size of ape, upright walking emerged far before mental developments
No-post cranial remains found, flat face, teeth are more hominid like (thick tooth enamel and position in jaw)
large ridges above eyes, lacks forehead (more ape-like characteristics), extends range of early hominids beyond East Africa

Question 21

Orrorin Tugenensis

Answer 21

“original man”, 5.6-6 mya, found in Kenya
Most post-cranial, which some tooth and jaw fragments
Femur shows bipedalism (neck of femur is very long)
Thick tooth enamel, 13 skeletons found

Question 22

Ardipithecus ramidus

Answer 22

a lot of skeleton is represented in fossil remains
found 1992, took 17 years to get them out of limestone
2009 saw publications of findings
Still has divergent big toe

Question 23

Australopithecus anamensis

Answer 23

4.2 - 3.9 mya
ethiopia, Kenya, and Eastern Africa
Lots of teeth and jaw remains, but also a tibia (tibia shows concave, thickened, large articular surface)
Most primitive/ape-ike of australopithecines

Question 24

Australopithecus aparensis

Answer 24

4-3 mya, east africa, 380-430 cc, smaller teeth than apes, mid face region projects forward, foramen magnum is forward, shallow, u-shaped dental concave

Question 25

lucy

Answer 25

most well known early hominid, discovered in early 70s by Johansen, really well represented skeleton, 3.3 mya, ethipia, only 3 feet tall, fully bipedial but probably retained ability to climb trees

Question 26

first family

Answer 26

probably killed in disaster like flood, 3.2 mya, remarkable preservation, no animal chewing/damage, no weathering, gives opportunity to investigate variation within speciies and growth/development, very sexually dimorphic, 9 adults, 4(?) juniviles,

Question 27

Dikika baby

Answer 27

aka selam, 3.3 mya, earliest and most complete child, extreemely well preserved, even has two kneecpas, 100 thousand years older than lucy but often refered to as Lucy’s baby

Question 28

laetoli, tanzania

Answer 28

east africa, first investigated in 1974 by mary leakey, many footprints and fossils, 3.6 mya; 70 footprints 3 sets 2 walking togehter, because it was in volcanci sediment, it was really good for radiocarbon dating, probably afarensis

Question 29

Australopithecus africanus

Answer 29

3-2 mya, slight brain increase 400 -500 cc less projecting face compared to afarensis, rounded cranial vault, slightly smaller front teeth, big molar, about 4”5 and 60 pounds

Question 30

Taung, South Africa

Answer 30

Taung Child, 3.3mya (?), Ryamond Dart, found in limestone quarry, high rounded forehead, roward forum magnum, full grow wouldve had 450 cc; findings published in 1925 byut weren’t accepted because it was a child and the piltdown hoax, puncture marks on back of skull may be remains of meal of large bird of prey

Question 31

Sterkortein, South Africa

Answer 31

Mrs. Ples, found in limestone quarry, ribs, pelvis bones, etc were found after, proved that it was human like below the head, ribs are rarely preserved

Question 32

Identifying characteristics of robust australopithecus

Answer 32

zygomatic arch (cheekbone area, very braod, makes for dish-shaped faces)
sagittal crest (area of muscle attachement, very large)
megadontia (molars and pre molars are bigger than expected compared to body size, enable to chew tough foods, nicknamed the nutcracker at first, could eat tough diet but analysis of tooth enamel shows that they had varied diet)

Question 33

paranthropus aethiopcus

Answer 33

2.5 mya, lake turkana, kenya “the black skull”, stained blue black from the maganese deposits, small brained, ~400cc, evolutionary “dead end: not part of evolution of genus homo, believed by most that robust austropithecus were dead ends

Question 34

paranthropus robustus

Answer 34

2.5 - 1 mya, swartkrans, South Africa, also found in other sites
530 cc

Question 35

paranthropus boisei

Answer 35

2.5-1 mya, mary leakey in 1959, koobi fora kenya and olduvai george tanzania, initially called zinjanthropus boisie but changed name because of similarities to australopithecus

Question 36

robust australopithecines

Answer 36

genus homo lived at same time as, no tools have been found in associated with early hominds, likely they used tools like chimps do, only one piece of possible evidene for manufactured tools

Question 37

Olduvai Gorge, Tanzania

Answer 37

100 meters deep, exposes 20 million yrs of history, Leakey spent careers working there, 1959 was the first discovery with the find of boisei
very defined strata, volcanic activity = great environment for fossil formation and allows for accurate dating