DEFINITIONS
The meaning of the word palaeoanthropology is lexically deciphered as ‘palaeo’ (meaning ancient) + ‘anthropos’ (meaning man) + ‘ology’ (meaning science). It is the science that deals with the study of evolution of man by unearthing the fossilised remains left by our early ancestors.
Palaeoanthropology has been defined firstly by Comas (1960) as “the study of hominid and anthropoid fossil remains, their proper interpretation and consequently, the possible establishment of phylogeny for our own species”.
Howell (1967) defined palaeoanthropology in a much better way as “investigation of biological relationships and the evolutionary history of the Hominidae and of the developments among the Hominidae the capacities and capabilities for culture”.
PRINCIPLES
Any palaeoanthropologist should always have at least the following six principles/ objectives in mind while dealing with the subject of palaeoanthropolgy.
- Identification
- Form and function
- Associations of plants and animals
- Evolution in the different groups of organisms
- Dispersal and distribution of plants and animals in time and space and
- Correlation
Identification
Any investigator must know as precisely as possible what he is dealing with since inaccurate information leads to erroneous conclusions. Frequently the fossil is too incomplete or the group to which it belongs is not known well enough for species identifications. Nevertheless, class, order and family can usually be recognised by any one conversant with his field of study. For this careful comparison is needed. If the species can be recognised, the specimens will be much more useful than if only their generic status can be established. Identification will be done by recognising the class, order and family and not only so, better identification can go up to genus and species level.
Example: Identification is done only if we know the anatomical details of any fossil specimen which we are dealing with. The dentition of fossil equids (Equus and Hipparion) although are very similar but one must be able to distinguish between genus Equus and Hipparion. In case of upper molars of Hipparion, the protocone is isolated but it is united and continuous in Equus. The morphological details between the genera can lead to correct identification otherwise it may lead to wrong conclusions.
Form and function By studying the structure of a fossil and drawing a parallel with living organisms the habits of extinct primates as well as other animals or plants can be realised. The form of the fossil then offers clues to how it functioned in the environment in which it lived.
Example: Man’s pelvis (hip bone) is designed to transmit weight from the trunk to the legs in comparison to the pelvis of the quadrupeds or brachiators (animals who walk on four toes). The early human fossils indicate that such modification of structure of pelvis over those of quadrupeds and brachiators was responsible for bipedalism (walking erect on two legs as is done by the humans).
Associations of plants and animals
Assemblages of plants and animals and the nature of the sediments in which they are entombed offer evidence of local environmental conditions of the past. It must be realised that fossils are not dead objects in the eyes of a palaeoanthropologist because he visualises them as they existed in their environment in the past.
Example:The palaeoecological conditions of fossil primates (Adapoid primates, Ramapithecus, Sivapithecus and Gigantopithecus, etc.) known from India and elsewhere can be reconstructed by taking into consideration both faunal and floral remains. It is also possible to reconstruct the community structure as well as inter and intra specific competition for food and space amongst various groups during the ancient time.
Evolution in the different groups of organisms
It has been shown that any type of plant and animal developed from an earlier and simpler ancestral form by transmission and change of hereditary characters. Changes were more rapid in some groups of organisms and slow in others or they may have been greatly accelerated in some at certain times. Some groups of marsupials (pouched animals) like the Opossum and fish with lung like structures have changed very little in the last 100 million years or more.
Example: The cranial capacity of our ancestors has gradually increased from 5 million years to 2 million years (350 to 400 cc) and then from 780 to 1020 cc by 1.8 million years before present and ultimately up to 1300 cc in the present day man. So the cranial capacity has greatly been accelerated in Australopithecus to Homo erectus and Homo erectus to Homo neanderthalensis and finally to Homo sapiens sapiens (i.e., from 350 to 1300 cc).
Dispersal and distribution of plants and animals in time and space Much of the evidence for dispersal and distribution is based on the evolutionary progression of animals and plants in the orders, families and genera and the occurrence of their fossils in the rock sequence of the earth crust.
Example: Most primitive primates, i.e. the Pleisadapoid and Adapoid primates which originated and lived during the Eocene and Paleocene of America and Europe later on dispersed and migrated to reach the Indian subcontinent as well as China during the Miocene times. From Miocene onwards these primitive primates might have branched to give rise to monkeys, apes and finally man.
Correlation
Much of the palaeoanthropologist’s time is spent in efforts to recognise synchrony of biological and geological events demonstrated by evidences in the rock units of the earths crust and in determining whether these events occurred in different continents or in adjacent mountains and valleys. The biological events demonstrated by the black Hawk Ranch fauna may be fairly clear in ones mind, but paleoanthropologist would want to know what kind of primates, animals and plants were living in the other parts of world, that is, Europe, America and Australia. So a correlation between the areas of one particular region may not be different, because of the proximity of the two areas and they may have numerous genera and species in common. However, it is difficult to correlate different continents since the distance between them is greater and in all probability no primate species could be found in these different continents.
Example: It is thought that the North America, South America and Australia were once connected with each other but following the geographic separation the Opossum developed into various marsupials which now inhabits Australia.
The time of their migration is not well known yet.
SCOPE
Every science is beneficial to the human being in one way or the other. Palaeoanthropology is also very useful in the following ways.
- Education and Relaxation
- Economic applications
- Knowledge of past nature
Education and Relaxation
People show great interest in knowing about the past life, their culture, habits, etc. This is well demonstrated by thousands of people who visit museums throughout the world to see something of the past life and some other forms of life, which is truly unknown to them. Palaeoanthropology helps in satisfying curiosity of general public about the evolution of the mankind and other major mammals. Palaeoanthropology also finds application in exhibiting the fossils in the museums for display purposes as well as it also provides great relaxation to the palaeoanthropologist when he finds some rare fossil primate including other mammals that no man has ever found.
Economic applications
Knowledge of the fossils as a guide to the sequence of rocks in the earth’s crust has been used in locating gold and other ore-deposits, for example, gold occurs in auriferous conglomerate at the base of the Cambrian over vast areas in Australia.
Proximity to these gold bearing formations can be determined by the age of the fossils in the overlying sedimentary rocks. Coal beds have been located by similar methods in the U.S.A and elsewhere. When polished, many limestone and fine grained sandstones with well preserved fossils make some of the most beautiful interior wall surfaces. Rich concentrations of uranium in fossil wood have also been discovered. Bones of dinosaur and other mammals also contain uranium.
Knowledge of past nature
Palaeoanthropologist with their knowledge of the past life can reconstruct the palaecology, palaeoenvironment and community structure which can provide important clues about early humans and their interaction and competition with past fauna and flora as well as about the evolution of man. Most of the knowledge about the climatic conditions in the geological past comes from the study of fossils.