Paper No. : 14 Human Origin and Evolution Module : 03 Terminological, taxonomic and chronological problems of fossils Development Team Principal Investigator Prof. Anup Kumar Kapoor Department of Anthropology, University of Delhi Dr. Satwanti Kapoor (Retd Professor) Paper Coordinator Department of Anthropology, University of Delhi Ms. Sangeeta Dey & Prof. A.K. Kapoor Content Writer Department of Anthropology, University of Delhi Prof. R.K. Pathak Content Reviewer Department of Anthropolo gy, Panjab University, Chandigarh 1 Terminological, taxonomic and chronological problems of fossils Anthropology Description of Module Subject Name Anthropology Paper Name Human Origin and Evolution Module Name/Title Terminological, taxonomic and chronological problems of fossils Module Id 03 Contents: 1. Introduction 2. Human Fossil Ancestors 2.1 Ramapithecus 2.2 Australopithecines 2.2.1. Australopithecus 2.2.2. Paranthropus 2.2.3. Chronological Implications 2.3 Homo habilis 2.3.1. General Characteristics 2.3.2. Chronological Implications 2.4 Homo erectus 2.4.1. General Characteristics 2.4.2. Chronological Implications 2.5 Neanderthal Man 2.5.1. General Characteristics 2.5.2. Chronological Implications 2.6 Rhodesian Man 2.6.1. General Characteristics 2 Terminological, taxonomic and chronological problems of fossils Anthropology 2.6.2. Chronological Implications 2.7 Homo sapiens 2.7.1. Cro – Magnon Man 2.7.2. Grimaldi Man 2.7.3. Chancelade man Summary Learning Objectives: To describe Human fossil ancestors and their discovery. To understand the chronological problems associated with the fossils. To describe the facts related to terminology of the fossils. To know about connecting links that lead to Homo sapiens sapiens. To understand impact of evolution through the fossil study. To identify the fossils by carefully examining the general characteristics of diverse human forms and variants. 1. Introduction Terminology or the application of appropriate word expressions in specific context to the subject; Taxonomy refers to that branch of science which is concerned with systematic classification of the organisms and the Chronology is the arrangement of the events or fossils in the order of their occurrence. In the present module, the terminological, taxonomy and chronology problems of human fossil ancestors were discussed. The geological time scale starts with the formation of the earth, some 4.6 billion years ago. The first and longest span of time was the pre-Cambrian, where forms of life were small, simple and soft- bodied. The onset of Cambrian about 570 million years ago marked the rise of shelled animals in the sea. Then followed the “ages” of the fish, Amphibians and Reptiles, culminating in the domination of land by the dinosaurs, from about 200 to 65 million years ago. 3 Terminological, taxonomic and chronological problems of fossils Anthropology Mammals first appeared more than 200 million years ago, but were overshadowed by the reptiles. However, some 65 million years ago all the dinosaurs – as well as other groups of reptiles on land, in the sea and in the air, and certain other animal groups and many plants too – became extinct over a relatively short period. This was only one of several “mass extinctions” that have occurred through geological time. The extinction marked the beginning of the Tertiary period and the Age of Mammals. The Tertiary is divided into epochs, and development in the primate group can be traced from the fossils they left in the rocks formed during the time. The first hominids (members of our family Hominidae) crop up in the fossil record less than million years ago. Mammalian evolution covers only about 4 percent of the Earth’s entire history, and humans have been around for only 0.1 percent of the history of our planet. The quest for our ultimate origins begins with the origin of life itself. The earth is about 4.6 billion years old. Fossil evidence shows that small, simple organisms were living at least 3 billion years ago. A great deal of evidence supports the notion that all present day organisms are related to each other, and these forms as diverse as slime molds and elephants, oak trees and beetles, roses and humans – ultimately arose from a single common ancestor, some 3.5 billion years ago. This means that a single evolutionary tree or phylogeny, relates all organisms, living and extinct. Biologists and palaeontologists assume that life evolved from its simple beginnings through a succession of stages, as represented in the fossil record, toward the present day diversity of some 10 – 30 million species. This does not mean that today’s diversity is in some way the destiny or the end point of evolution; there has been great diversity in the past, and there may be in the future. 2. Human Fossil Ancestors The course of human phylogeny or the human biological evolution like other mammals can be followed only from the fossil records. Though the fossil records are fragmentary, the paleoanthropologists have been able to piece them together and draw them an almost complete phylogeny of primates and of modern man, Homo sapiens sapiens. The early stages of human biological diversity can only be studies by comparative anatomy of fossils and also by comparative biochemistry of present day humans, apes and other primates. Information on the later stages in human 4 Terminological, taxonomic and chronological problems of fossils Anthropology evolution are based on artifacts that include stone tools, pottery, fire – hearths and the fossils of other animals along with human fossils. https://www.google.co.in/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&ved=0ahUKEw jP2oij_sPTAhUBrI8KHW74BywQjRwIBw&url=http%3A%2F%2Fwww.portal.gsi.gov.in%2 Fpls%2Fportal%2Furl%2Fpage%2FGSI_STATIC%2FGSI_STAT_GEOLOGY_LIFE_AGES &psig=AFQjCNFsx3p8DjiWKjA4dY2wrzEn5hpFdw&ust=1493360154025061 The fossils of pre-human and ancestral human forms are obtained from widely diverse regions of Africa, Asia and Europe which indicates that man’s centre of origin was probably in Asia and Africa. More precisely human must have been originated from central Asia because the oldest known fossils have been obtained from Asia, China, Java and India (Siwalik hills); the number of domesticated animals and plants is maximum in Asia; A number of migrations of animals have occurred in the past from Asia; Asian culture appears to be the oldest culture; the climatic conditions in Asia and nearby places were most conductive for human evolution and rich fossil beds are discovered from rift valley in East Africa, where Hominid fossils have been found. These areas are – Olduvai Gorge, Lake Victoria and Lake Natrona in Tanzania and Lake Turkana in Kenya. Through the fossils records, it can deduced 5 Terminological, taxonomic and chronological problems of fossils Anthropology that the last and most important hominid from Miocene is Ramapithecus and through evolutionary processes it evolved to Homo sapiens sapiens of modern times. 2.1. Ramapithecus The last and most important hominid from Miocene is Ramapithecus. It is accepted by many scholars to be the first true hominid. Ramapithecus dates back to the tie period between 14 – 10 million years ago. It was discovered and christened as the Rama’s ape by Edward Lewis in the year 1934. The specimen was later analyzed by Simons in the year 1964. Simons gave the name Ramapithecus punjabicus to this find, which was a long time thought to be the highest evolved form in the Hominid evolution, belonging to the ape group of Dryopithecus. The fossils of Ramapithecus (Primarily teeth and jaw) come from two areas: the Siwalik Hills in India and Fort Ternan in Kenya. Other specimens have been discovered from Turkey, Hungary and Greece. The Ramapithecus fossils roughly date back to periods between 14 and 9 million years ago. The ecological setting of Fort Ternan and the Siwalik Hill fossils is that of a forest woodland environment. The Greek fossils, being younger, are that of a drier, savanna like environment. The hominid features of Ramapithecus include reduced and vertically implanted incisors, and canines, little or no diastema, flattened and thick enamelled premolars and molars that appear to be adapted for heavy chewing and processing of heavy food stuffs. Moreover, the placements of chewing muscles indicated an increased chewing pressure brought to bear on the food being eaten. These features, sufficiently different from the earlier Miocene fossils, indicate Ramapithecus direction to hominid line – perhaps the first hominid. Ramapithecus specimens very strongly suggest the exploitation of a new dietary source – most likely seeds, nuts and grasses – that indicate a shift from the softer forest fruits and vegetables relied upon by apes. This dietary shift is rather clearly associated with the climatic changes in the later part of Miocene that led to an increase in open grasslands and the decrease in the forest habitat of apes. There is a greater probability that this hominid form apparently was moving into a new ecological niche; it was beginning to exploit a more open ground environment similar to that inhabited by later hominids. 6 Terminological, taxonomic and chronological problems of fossils Anthropology Ramapithecus is also the most likely candidate for the ancestry of later hominids because of its presence in an area where the next hominids – the Australopithecus - have been found. The possible adaptation that Ramapithecus made to open – ground living include an increased degree of hand and finger preparation of food, perhaps more frequent use of tools in such preparation, a tendency towards upright posture and bipedal locomotion for movement with a wide field of vision through the tall grasses on the open plain, possibly longer periods of growth and development, and perhaps, even a more frequent inclusion of meat in the diet. None of these adaptations can be clearly demonstrated because of lack of fossil evidences, but what we do know is that these adaptations were clearly present by the time the next phase of hominid evolution – the Australopithecus – had began.