Anthropology Optional (Primatology) by Sourabh Mishra

Model Answer

Question #1. Jane Goodall's contributions to primatology  10 marks (150 words)

Approach

1. Introduction: About Jane Goodall
2. Findings- primate behaviour, nonverbal communication etc
3. Significance- Inferences about Homo sapiens.

Hints:

Jane Goodall is an English primatologist and anthropologist. Considered to be the world's foremost expert on chimpanzees, Goodall is best known for her 60-year study of social and family interactions of wild chimpanzees since she first went to Gombe Stream National Park in Tanzania in 1960, where she witnessed human-like behaviours amongst chimpanzees, including armed conflict.

Her dedicated and pioneering research is now recognized as a milestone in primate ethology. Her two books, In the Shadow of Man and The Chimpanzees of Gombe: Patterns of Behaviour are major contributions to the scientific literature on pongid behaviour.

Goodall's pioneering research has resulted in original information on wild chimpanzee vocal communication, sexual activity, social hierarchies, facial expressions, greeting gestures, parental care, nest building, diseases, diet, grooming, and play. In general, chimpanzee behaviour bears uncanny similarities to human behaviour.

Findings after chimpanzee study:

• A shifting band of 60-80 members consists of a hierarchy: adult males with a temporary male leader, young males, females with babies, and females without babies.

-A chimpanzee group is dominated by the top-ranking or alpha male, and each sex has its own fluctuating dominance hierarchy

• There is no nuclear family unit; the only temporary bonding relationship is the parental care of an adult female for her infant or juvenile.
• In nature, chimpanzees live a casual life within constantly shifting groups (these societies meander within a home range). They may even defend their territory against other intruding chimpanzee units.
• Chimpanzees show much individuality, differing in their facial expressions and mannerisms. They are very intelligent and highly emotional: their temperament ranges from violent aggression to gentle playfulness. Actually, one may even speak of chimpanzee personalities.
• Chimpanzees communicate and control behaviour through a variety of calls as well as by touch, gesture, and cooperative behaviour patterns (especially play and grooming).
• Goodall's major discovery is that wild chimpanzees make, use, and transport simple tools. They deliberately modify stems, twigs, sticks, or blades of grass for the specific purpose of probing insect mounds at certain times in order to extract and eat ants or termites
• Goodall was the first primatologist to observe the frenzied "rain dance" ritual of this great ape, a stylized display of apparent nervous behaviour. During a thunder-and-lightning storm, excited male chimpanzees stage a unique pattern of activity: They leap to the jungle floor and careen through the grass, then charge downhill while bellowing and brandishing boughs; this activity is followed by the act of slapping the ground or swatting at trees.

Significance/Inferences of these findings

1. The study of primate behaviour is essential for giving us clues to the possible behaviours of our ancestors.
2. We can know about the possible reasons for the origin of:
3. Factors and forces behind a shift to bipedalism
4. Language, supporting the need hypothesis
5. Notions of territoriality
6. Development of a social organization and consequently family
7. Adaptations to adjust to external environment

Conclusion:

However, it is an important study in its own right. It has now become our responsibility to manage much of the life on this planet, and in order to preserve what we currently have, we need to understand what the animals require in terms of space, diet, group organisation etc.

Question #2. Discuss the evolutionary significance of bipedalism and erect posture. 15 marks (250 words)

Approach

1. Introduction- Hominization process
2. Biological changes associated with the process
3. Cultural significance of changes
4. Conclusion- Evolution as a continuous process

Hints:

In the history of primate evolution man evolved from non-human primates. Gradual evolution from terrestrial quadrupedalism (pronograde) to semi-erect posture (clinograde) and finally to a fully erect posture (orthograde) with bipedal locomotion is the way how the evolution of locomotion from simians to man has been interpreted.

Man deserves its name when he could stand erect and walk bipedally. We stand with our back vertical, legs straight and our arms and hands hanging down freely on the side of the body.

On the other hand our primate relatives, even if they stand, they do it with a slopping back, bent legs and arms and hands hanging down in front of the body. The assumption of such an erect posture has consequences on our skeletal system. Anatomical modifications that took place on the skeletal system due to assumption of erect posture vary in magnitude in different parts of the skeleton.

Changes are observed to be more prominent on skull, vertebral column, pelvic girdle, femur and foot.

PELVIC GIRDLE:

• When an individual stands erect, his whole body weight is to be transmitted on the hind legs through pelvic girdle. Therefore the pelvis plays a great role in getting an erect posture and naturally had experienced a number of changes.
• It is said that pelvis changed rather more than the vertebral column during the evolution of habitual erect posture and bipedal gait (Buettner Janunsch).

FEMUR:

• In an erect standing animal the entire weight of the trunk and upper extremity is to be transmitted from the pelvis to the femur which in turn supports the same. Therefore in order the bear the load of the weight, the femur has to experience a number of modifications from the femur of the quadrupedal or semi erect postured primates.

FOOT:

• With the assumption of erect posture and bipedal walk, the hind limb is no longer a grasping organ but locomotory organ. As such changes necessary for modifying this grasping foot into an organ capable of supporting the weight of the body is fairly clear.

Evolutionary significance:

• Bipedalism allowed hominids to free their arms completely, enabling them to make and use tools efficiently, stretch for fruit in trees and use their hands for social display and communication.
• They could also see further over the savannah grass - but this also could have been a disadvantage since predators could probably spot them more easily
• Bipedal hominids could spend more time foraging and scavenging out in the open savannah because their bodies would be exposed to less sunlight standing upright.
• Evolution Walk Bipedalism allowed hominids to free their arms, allowing the use of tools
• Walking on two limbs was also more energy efficient than walking on four - giving early hominids more energy to reproduce and therefore more chance of producing offspring bearing this unique trait.
• Even though bipedalism is slower at first, over long distances, it has allowed humans to outrun most other animals according to the endurance running hypothesis.

Impact on Physical evolution:

One of the things that makes our species unique is our exceptionally large brain relative to body size. A new analysis of the skull suggests that human brain evolution may have been shaped by changes in the female reproductive system that occurred when our ancestors stood upright. Bipedalism involved a major reconfiguration of the birth canal, which became significantly narrower because of a change in the structure of the pelvis.

Biological significance

• Precision grip- tool formation
• Long distance travelling- out of Africa; migration and dispersal
• Shifting of larynx- communication
• Pressure on frontal cortex- enlargement of brain; reduction in jaw; perfection of facial contour
• Narrowing of birth canal- sexual dimorphism
• Rough linea aspera- more surface area for muscles to attach.
• Formation of S-shaped invertebral column which promotes greater stability with a larger head being supporting on the vertebral column instead of hanging ahead of the body.

Cultural significance:

• Tool formation led to food processing and taming the environment.
• Fire production- cooking food-> change in micro biome-+ less parasites in food-+ longevity
• Sexual dimorphism-+ longer gestations development of family due to male dependence
• Persistent running- better hunting capability
• Terrestrial living
• Better exploitation of the environment: clearing of forests.

Conclusion:

The talus bone is also enlarged and wedge shaped to serve the purpose of transmitting the weight to the great toe while walking. So these are some of the anatomical changes or modification that we have observed on the pelvic girdle, femur and foot of man due to assumption of erect posture. Evolution is a continuous and protracted process and we are still evolving under newer forces.