Introduction to the Study of Human Evolution

Scope of the Study, Recent Trends and New Perspectives

Human Evolution as a Narrative● The study of human origins is

ultimately a narrative on our place in Nature and a reflection on the attributes which distinguish us from other animals

● This reflection must bring us into the realm of philosophy no matter how objective we endeavour to be in our studies

● At once, it causes conflict with literal interpretations of the major religious traditions of Europe and the Middle East (Judaism, Christianity, Islam) in that the divinely ordained place of Man as elevated above the animals is contradicted

● It also causes conflict amongst those philosophical traditions that argue for the special characteristics of the human spirit and intellect

Significance of Evolutionary Studies● This should not, however, imply that conflict

with these traditions is inevitable

● Religious traditions that do not interpret the holy books as literal expressions of historical truth, but take a more allegorical and critical approach, can accommodate evolutionary thought quite comfortably

● Moreover, some of the psychological works have been keen to incorporate the main findings of evolutionary theory: the works of Carl Jung and Sigmund Freud, for instance, built on the ideas of behavioural and psychical structures common to primates and mammals

● Some specialist studies in psychology are concerned explicitly with primate behaviour and use their results to elucidate childhood development

● Even the phenomenological schools of thought in modern philosophy have profited greatly from evolutionary theory

Problems● We must recognise at the outset that the

evolutionary paradigm is not without problems and major gaps

● Firstly, the fossil record is incomplete and large unrepresentative inasmuch that there are simply not enough remains to be certain of the scope of diversity

● The recent discovery of the 'Hobbit Man' has also emphasised how much we still have to find and the problems inherent in the spatial and temporal distribution of the evidence

● Secondly, the evidence is subject to much controversy and the reconstructions are based on a chain of suppositions that may not all be applicable

● This reflects the paucity of remains and also their condition—it is rare to find more than a few small fragments and inferences concerning the rest of the skeleton must be made from these

Problems, continued

● A third problem arises from the contributions of other disciplines, mainly those made by genetics

● Archaeologists are not competent to assess the genetic evidence, and even amongst geneticists there is considerable uncertainty regarding the implications of the findings

● Some of the most important breakthroughs in the study of human evolution have been provided by geneticists in recent decades, and the archaeological and fossil record has been reconsidered according to these studies

● A danger therefore exists of us formulating circular arguments to support hypotheses deriving from other disciplines

Concepts of Human Origins

Before the Advent of Evolutionary Theory

Man and Nature● The major religious faiths of Europe and the

Middle East averred that humans were set apart from the natural world and that a chasm therefore existed between us and other living organisms

● In Biblical tradition, Man was divinely accorded supremacy over animals and plants because he was created in God's image

● The Medieval understanding of this resulted in the explicit formulation of an hierarchical structure, with Man being situated below God and the angels and above all the other creations—namely, animals and plants

● This is sometimes described as the Great Chain of Being and became important in natural philosophy

● A good summation of this concept can be found at:

http://www.earlham.edu/~peters/courses/re/chain.htm

Nature and Change● The Chain of Being, elaborated and

formalised primarily by Renaissance philosophers, implied the immutability of relations amongst species

● No philosophical scope for changes in species, resulting in the transformation of their position in this chain, was therefore possible as their respective situations were divinely ordained

● This should perhaps be regarded partly as an expression of Medieval and Renaissance conceptions of essences, which in itself is derived from the philosophical works of Plato and Aristotle

● An essence or spirit cannot be transformed and was granted by the Divine

A Biblically Derived Chronology● No philosophical grounds for disagreement

with the Biblical record were therefore present

● It was accepted that the Bible was an reliable record and scholars attempted to establish the antiquity of Man by tallying biblical chronologies, combining these with other historical records, and various astronomical calculations

● Most famous and authoritative of these chronological determinations was that proffered by Archbishop of Armagh, James Ussher (1581 – 1656)

● He concluded that the Creation had occurred 'upon the entrance of the night preceding the twenty third day of October' in the year 4004 BC

● This left roughly six millennia for the creation of the planet, but it must be recalled that the Greek histories extended back to roughly 700 BC and therefore the entirety of the prehistoric era had to be accommodated within the period 4004 BC – 700 BC

Doubts Concerning the Biblical Chronology● The literal interpretation of the

chronological scheme presented in the Bible was not, however, accepted uncritically by all

● Philosophers such as John Ray expressed worries and wrote in a letter that fossils would 'shock the Scripture-History of ye novity of the World'

● Another expression of discomfort with the literal Biblical chronological structure was made by Thomas Burnett that attempted to reconcile his impression concerning the antiquity of Earth and Man by suggesting that the accounts of Creation in Genesis were allegorical

● Problems with the accepted age of the planet and man were also expressed by the astronomer Edmund Halley and published in 1715, but his concerns arose from empirical observation rather than philosophical speculation

Finding Time for Evolution

Geological Contributions to the Antiquity of the Earth and Life

Emergence of Geology● The principal problem with the Biblical

chronology, according to the observations of eighteenth century scholars, was that it did not provide sufficient time for some processes to take their course

● Some attempted to overcome this by arguing for catastrophic changes in the environment and life—namely, that the Deluge had obliterated the extinct species seen in the fossil record and the Earth was repopulated in a fresh wave of Creation

● This theory was known as Catastrophism, but it was quickly and cogently challenged by the seminal studies undertaken by James Hutton (1726 - 1797) in Edinburgh, the Lothians, Berwickshire and Northumberland which were based on observations of current rates of erosion

Uniformitarianism● The proponents of catastrophism

and the Biblical chronological framework required special pleading to explain the formation of certain geological features

● This is because observation of erosion and sedimentation demonstrated that these processes occurred very slowly

● If these processes were assumed to have prevailed in the past, the formation of some features would have taken tens of millions of years to form

● This theory was championed by Thomas Hutton and is commonly known as Uniformitarianism—that is to say, the the processes operative today are the same as those in the past

Sufficient Time Depth

● The implications of Hutton's work were not fully developed until the first half of the nineteenth century when Charles Lyell (born in Kinnordy) published his book 'Principles of Geology' in three volumes (1830 – 1833)

● This publication could not have come at a more opportune time, for in France the work of Jacques Boucher de Crèvecœur de Perthes in the Somme Valley was affording evidence of flint tools in association with the bones of extinct animals

● The antiquity of the Earth was established by the work of Hutton and Lyell, which made it sensible to speak about the antiquity of Man, or at least the likelihood that the human family was older than six thousand years

Rivers and Hominids● The evolution of rivers was understood in

broad outline at the time of de Perthe's work, which made the discoveries at different levels of the terraces so surprising

● Moreover, the human remains that occurred along with the fossils were sometimes unusual—this was not recognised as evidence for hominid species preceding the emergence of modern humans at the time, but it did suggest that our ancestors might have been different

● The importance of the work by Hutton, Lyell and de Perthes to the study of evolution can be traced through their profound impact on the theories of Charles Darwin

● The captain of the Beagle was, indeed, asked by Lyell to collect boulder samples and the first volume of his book was passed by the captain to Darwin on the voyage

● All this work therefore helped Darwin's ideas seem both possible and plausible

Evolution and Hominids

The Impact of Darwin's Theories and the Discovery of the First Hominids

Evolutionary Theory● The theories of Charles Darwin, and their

profound influence on the intellectual climate of the nineteenth century, are too well known to warrant much discussion

● It should be noted, though, that his theory afforded a mechanism and process of evolution for the physical transformation of species

● Moreover, the theory was also taken over by those studying behaviour and culture and this was ultimately also applied to the archaeological record

● The main problem was, however, the absence of fossil hominid species to confirm the applicability of Darwin's theories to human evolution

● This caused a great stir amongst geologists and archaeologist as they embarked to find such evidence

The Earliest Finds● The first find of an archaic hominid

went unrecognised—it was found at Engis, in Belgium, in 1829

● This was followed by a discovery in Forbes' Quarry in Gibraltar in 1848

● Both of these specimens were from Neanderthal, but it was the find at Eckrath near Düsseldorf in 1856 (three years before 'The Origins of Species' was published) that was most immediately significant because of its timing

● The theories of Darwin forced a reassessment of these finds and they were soon the subject of strident controversy and discussion

● This signalled the beginning of palaeoanthropology as a discipline

Interpretation● The discovery and acceptance of the

Neanderthal remains was a relatively straightforward matter when compared with the interpretation of the finds and the perceptions of the behaviour and attributes of this species

● Insofar that Neanderthal was seen as being situated somewhere between Man and Ape, the species was regarded as resembling the 'lesser' races behaviourally, intellectually, spiritually and anatomically

● It can only be said that the earliest depictions were implicitly racist in some instances, whereas in others the ape-like characteristics were enhanced to emphasise the distance between this species and modern Europeans

Neanderthal as Ape

Assumptions and Preconceptions

● Some sought to explain the patterns in the Neanderthal archaeological record with reference to the 'lesser' races, which was becoming quite common in social anthropology in the Victorian era

● Others did not even go so far, preferring to see this species as some sort of bipedal ape that shared few behavioural attributes with humans

● Both interpretations were based on assumptions of their situation in the evolutionary hierarchy rather than on any evidence, and this is something that continues to plague us in our reconstructions and preconceptions of archaic hominids nowadays

Neanderthal as Human