1. What do you mean by climatic background to human evolution?
Ans. Towards the end of the Miocene, between seven to five million years ago, an abrupt drop in global temperature coincided with the formation of the West Antarctic ice sheet, Sea levels fell, the tropical belt shrank residing widespread extinctions of primates throughout Eurasia. Grassland expanded in Africa. This was the time when the hominids appeared who lived in woodland rather than forest. A second sharp change of global climate occurred around three million years ago when the northern ice-cap formed for the first time. This was the time of first appearance of the genus Homo.
2. What are the differences between apes and man?
|Cranium expanded, maximum brain 750 c.c.||Cranium greatly expanded, maximum brain size 2,000 c.c. (in some fossils)|
|Occipital condyles posterior||Occipital condyles anterior|
|Palate long||Palate reduced|
|Dental arcade V-shaped||Dental arcade parabolic|
|Incisor and canine teeth large||Incisor and canine teeth reduced|
3. State six features of the hominids.
a. True forehead.
b. Parabolic shaped dental arcade.
c. Relatively reduced jaw.
d. True chin.
e. Fully erect posture.
f. Non prehensile foot and true precision grip.
4. Which fossil is the most famous forerunner of the Great Apes? Characterize it.
Ans. The most famous of the Miocene apes has been classified as Dryopithecus, the oak-ape, so called because of the presence of oak leaves in the fossil beds. They were a relatively successful group, having flourished for at least 10 million years. The African variety Dryopithecua africanas first named Proconsul showed a curious mixture of monkey and ape, characters- 1. Long trunk is monkey like, 2. Arm, hand bones, shoulder and elbow regions apelike, 3. Large projecting canines ape-like, 4. Molars elongated from front to back.
5. Who are the forerunners of the hominids?
Ans. Rapapithecus and Sivapithecus, both were named after dieties Rama and Siva, were, were the forerunners of the hominid. Anthropologists have still argued over whether these fossils were the first ancestral hominid or an ancestral pongid or merely an evolutionary dead end. David Pilbeam (1972) favors the view that both the forms were ancestral to the Orangutan which split off from the lineage leading to hominids about 16 million years ago.
6.Why controversies are centered around Ramapithecus?
Ans. Ideas about the origin of the hominid lineage have undergone something of a revolution in the past few years. This is because Ramapithecus had long been a favorite candidate as the first hominid was shifted off the main path of human ancestry. The ramapithecines lived in the Miocene period from 14-8 million years ago. Their remains have been found from Africa, Near East Asia. There are certain features of this form considered in favour of relating them to hominids such as short muzzle, small canines, similar molar etc. But there are certain features against this view too such as V-shaped dental arcade, more arboreal, smaller size etc. Until more complete remains are found they will remain an enigmatic group.
7. Who are the undeniable hominid? Write four features of them?
Ans. The first undeniable hominid, Australopithecus arrived at about 4 million years ago. In 1924, Raymond A. Dart first discovered the skull of such form from Transvaal region of South Africa. The features of Australopithecus are -1. Short muzzle, 2. Walked upright on two legs, 3. incisors are relatively large, 4. Have had long fore limbs and short hindlimbs, 5. Two forms as heavily built robust and lightly built gracile have been recognized, 6. Crucial capacity ranged from 450-600 c.c.
8. What is the importance of “Lucy” in human evolution?
Ans. One of the most famous of all the discoveries related to Australopithecus afarensis is ‘Lucy ‘ found at Hadar by Donald Johanson (1978). About 40 % of Lucy’s skeleton was found and she is the most complete australopithecine known. According to many anthropologists A. afarensis is the ancestor of all subsequent hominids. The advanced features of such form are, 1. squat structure of pelvis indicates bipedality, 2. structure and angle of knee joint and foot bones are also consistent with bipedality, 3. the opposable great toes as in modern apes are lost, 4. dentition is a mixture of hominid and ape characters.
9. What features put H. erectus far ahed of former hominids?
Ans. H. erectus (‘upright man’) lived about 1.6-0.2 million years ago. Probably evolving in Africa groups spread to Europe, East Asia (including Peking man or Sinanthropus), and South East Asia (java man or Pithecanthropus), Isolated populations seemingly evolved at different rates. Their main features are 1. Brain, 880-1100 c.c., 2. a shelving forehead, thick brow ridges, 3. flatter face and big projecting jaws, 4. some adults grew up to 6 ft. tall, 5. used fire and also tool makers, 6. keeled top of the skull.