Evolution - Chapter 13

Question 1

The Laetoli footprints

Answer 1

• evidence that early hominins existed over 3 million years ago.
• made by Australopithecus afarensis 3.56 million years ago

Question 2

Features of the footprints that indicate bipedal locomotion:

Answer 2

• a deep impression showing the heel hitting the ground first
• the lateral transmission of weight from the heel to the ball of the foot
• a well developed longitudinal arch
• a big toe that was parallel to the other digits
• a deep impression where the toe pushed the foot forward for the next stride

Question 3

What/who is ‘Lucy’?

Answer 3

• remains of a fossil known as Lucy were found in the Hadar region of Ethiopia
• is a female skeleton and was 40% complete
• classified as Australopithecus afarensis

Question 4

Features of australopithecines

Answer 4

• canines are short and non projecting
• incisors and canines make a row of cutting teeth, there is no gap between them and the following premolars
• the teeth are in the parabolic shape distinctive of the hominids
• low forehead and more projecting upper and lower jaw than modern hominin profiles
• brain size 480cm^3
• truly bipedal but gait would have not been same as humans
• femur, pelvis and carrying angle much more like humans than apes
• foot possesses a non-opposable, strongly built, robust big toe
• foramen magnum more forward than in other apes, skull more rounded at the back
• s-shaped curvature of vertebral column

Question 5

Paranthropus robustus

Answer 5

• existed in South Africa 1.8-1.2 million years ago
• not an ancestor of modern humans, but instead part of the evolutionary branch
• share many characteristics with australopithecines

Question 6

Features of Paranthropus robustus

Answer 6

• females height = 1m
• males height = 1.2m
• cranial capacity of 520cm^3
• large sagittal crest for attachment of strong chewing muscles
• very large molars and premolars, with small incisors and canines by comparison
• prognathism, less than australopithecine
• wide, dish shaped face with large zygomatic arches
• heavy brow ridges
• structures for bipedalism

Question 7

Homo habilis

Answer 7

• found in Olduvai Gorge in East Africa
• known as the handy man to indicate that it was adept at tool making
• larger brain and smaller teeth than australopithecine - suggests their diet could include meat
• lived between 2.3-1.5 million years ago in eastern and Southern Africa

Question 8

Features of Homo Habilis

Answer 8

• females height = 110cm
• males height = 130cm
• brain size of 610cm^3
• rounder skull
• small brow ridge
• central foramen magnum
• moderate prognathism
• teeth arranged in a rounder arc
• relatively short legs and long arms
• slightly curved finger bones, indicating a strong power grip
• able to form a precision grip

Question 9

Homo Erectus

Answer 9

• life on ground rather than in trees
• fossil known as the peking man
• found in Beijing
• dental arcade was shorter and more rounded at front and jaw was more compact and teeth were very modern indicating they had a diet much like humans today

Question 10

Features of Homo Erectus

Answer 10

• varied height, ranging from 145-185cm^3
• short, stocky body with thicker bones, suggesting a demanding lifestyle
• average cranial capacity of 1050cm^3
• low, sloping forehead
• defined brow ridges
• large, thick jaw without a chin
• reduced size of molars

Question 11

Feature of Homo Neanderthalensis

Answer 11

• features evolved due to a cold, harsh climate
• big faces, low but large skulls, heavy brow ridges
• brain slightly larger than the average humans today
• back of the skull drawn out in a bun shape
• lower jaw lacked a definite chin
• cheeks swept back to give streamline appearance
• large, wide, projecting nose (adaptation to life in seasonally cold dry environments)
• short in stature - males 1.5m and females shorter
• limbs short and heavily jointed with powerful muscles
• barrel shaped chest and thick neck muscles

Question 12

Size on neanderthals brain and why?

Answer 12

average brain size was 1485cm^3 which is larger than humans. it is suggested that the additional brain capacity was probably required for control of the extra muscles.

Question 13

Homo Sapiens

Answer 13

• fossils found in Europe
• fossils called Cro-magnon and were discovered by workmen building a railway
• found 5 people together with seashells in form of necklaces, and stone tools
• fossils were apart of a once widespread population throughout Europe from 40 000 - 12 000 years ago

Question 14

Cro-magnon people

Answer 14

the first anatomically modern people found in Europe

Question 15

Features of Homo Sapiens

Answer 15

• skulls shorter from front to back, higher in the region of the top of the skull and rounder at the back
• less prominent brow ridges
• reduction in the projection of the face
• smaller jaw
• brain size = 1350cm^3
• face was relatively broad and short with eye sockets well separated
• smaller teeth and developed chin