The unlikely interbreeding between Homo neanderthalensis and Homo sapiens

 

Schematic of possible Neanderthal and Human interbreeding.  Source: public domain.

1.  Introduction

The Neanderthals are extinct hominids who inhabited Europe and western Asia circa 300,000 to 30,000 years ago. During this time they co-existed with modern humans. The issue of whether Neanderthal populations, circa 35,000 BP, interbred with and/or were acculturated by anatomically modern humans, or became extinct in isolation, is still a matter of controversy and debate. The transition from the Middle to Upper Palaeolithic in Europe occurred some 40 to 30,000 years ago, and saw the extinction of the Neanderthals and appearance of anatomically modern humans (AMH).

Three basic hypotheses have been postulated to explain the fate of the Neanderthals: (1) Neanderthals were transformed in to modern Europeans, and thus direct ancestors of modern Europeans; (2) anatomically modern humans from the Near East completely displaced the Neanderthals who contributed nothing to the AMH gene pool; (3) partial admixture took place in the expansion of AMH from Asia and thus contributed some genes to AMH. (Trinkaus, 1993; Stringer, 1993). General support, based on molecular genetic variation analysis, is usually given to the second view – the Neanderthals constituting a separate species that went extinct without contributing genes to modern humans. (Cann, 1987; Vigilant, 1991; Hammer, 1995).

2.  The Matter of Interbreeding

Mitochondrial DNA, or mtDNA, is maternally derived non-nuclear DNA and underpins the concepts of an African ‘Eve’, with mtDNA the mitochondrial ‘Eve’. Gene flow studies are set by observations of human mtDNA. Analysis of morphological differences between skeletal remains classify Neanderthals and modern humans as separate species (Zollikofer, 1995; Hublin, 1996). Again, skeletal evidence associated with Aurignacian technology shows it was produced by AMH (Stringer, 1990), and the archaeological evidence “…seems to indicate that Chatelperronian Neanderthals and early Aurignacian modern humans were biologically different groups with important similarities in the cultural development.” (d’Errico, 1998).

However, the mtDNA results “…do not rule out the possibility that Neanderthals contributed other genes to modern humans.” (Krings, 1997). The first AMH in western Europe were the Cro-Magnon people, who were typically modern, even though they were “…continuously exposed  to potential admixture with Neanderthal. Cro-Magnon seems to emerge essentially unmixed.” (Cavalli-Sforza, 1997). It is known that archaic Neanderthals lived alongside for 30,000 years at Qafzeh in the Near East. AMH who had been there 92,000 years BP (Fagan, 1996), and further thermo-luminescence dates gave 36,000 years ago for Neanderthal artefacts in France. Despite lack of signs of admixture in most western European AMH it has been argued that, before they disappeared, Neanderthals may have established relations with AMH and hence “…may have contributed to the gene pool of modern Europeans.” (Cavalli-Sforza, 1997).

The ‘Out of Africa’ scenario, considering the Neanderthal mtDNA sequence shows that modern humans arose in Africa as a distinct species and “…replaced Neanderthals with little or no interbreeding.” (Krings, 1997). An alternative view postulates that expanding AMH populations or groups possibly admixed with earlier types but social and cultural barriers to inter-fertility may have been more important than biological factors (Cavalli-Sforza, 1997). The debate continues concerning the nature and timing of any interactions “…between ancient modern humans and Neanderthals with…emphasis on the degree to which Neanderthals contributed genetically to the earliest modern human populations in Europe.” (Weaver, 2005). Neanderthals and AMH lived in greater proximity in the Middle East where intermingling could have been a possibility – except the fact there is ”…no evidence Neanderthals and AMH lived at the same time: in fact in the Middle East, they are widely separated in time.” (Cavalli-Sforza, 1997). With regard to ancient DNA, the late survival of Neanderthals, and modern human-Neanderthal genetic admixture, most anthropological geneticists, human palaeontologists, and palaeological archaeologists “…now favour a predominantly extra-European origin for the earliest modern human populations in Europe.” (Weaver, 2005; see also Stringer, 2003; Trinkaus, 2003; Underhill, 2001). The analysis of diversity and global patterns points to a recent African origin of modern humans (Armour, 1996;

Bone analysis indicates that Neanderthal DNA is separated from modern humans by a great distance in evolutionary terms, with mtDNA separation some 500,000 years ago. Therefore the analysis of mtDNA from multiple fossil Neanderthal remains confirms ”…abundant skeletal evidence that Neanderthals were biologically distinct…from Holocene (recent) humans and at least some more ancient modern humans (Weaver, 2005; see also Knight, 2003; Serre, 2004). It seems that Neanderthal mtDNA is actually distinctive which means they differed substantially from AMH. (Krings, 2000; Krings, 1997; Ovchinnikov, 2000). This points to no interbreeding, possibly due to incompatibility, and the reclassification of Homo neanderthalensis sapiens to Homo neanderthalensis. Placing Neanderthal mtDNA variation outside modern human ranges is used to study outcrops in phylogenetic analyses in order to “…assess the geographic origin of the human mtDNA ancestor…however new methods of phylogenetic analysis have continued to support an African origin of human DNA variation.” (Penny, 1995).

3.  The Matter of Displacement and Isolation

The minimum date for the divergence of Neanderthals and modern humans has been given at 250,000 to 300,000 years ago. The mtDNA divergence date suggests 550,000 to 600,000 years ago, whereas the archaeological record indicates some 300,000 years ago. Therefore, if the evolutionary trajectories of Neanderthals and AMH separated over 500,000 years ago, then “…the possibility of such genetically based divergences in brain structure, neurology, and cognitive capacities can in no way be ruled out.” (Mellars, 1998). Some 28,000 years ago modern humans had replaced Neanderthals in Europe after their expansion into the east and west (Stringer, 1996).

Questions concern possible replacements, admixtures, and complex evolutionary phenomena, involving interaction between Neanderthals and expanding AMH (Cavalli-Sforza, 1997). Before 45,000 BP Neanderthals had the landscape alone, by 35,000 they disappeared from France, with the last Iberian outpost lasting until 27,000 BP. Some argued that localised Neanderthals evolved into AMH (Wolpoff, 1989), others that replacement occurred by migrating AMH because, after 15,000 years of interaction Neanderthalers “…were driven to extinction by the technologically and presumably socially more advanced Homo sapiens sapiens.” (Conard, 1998). Though the two groups shared a large territory, low demographic intensity, and discontinuous settlements, few biological interactions occurred with a few behavioural imitations (Hublin, 1998). If the Chatelperronian is unique then independent parallel development – ending 35,000 BP – occurred which excludes acculturation implying cultural divergence (Svoboda, 1998), indicating Neanderthals “…were the victims of us modern humans, who indisputably presided over their demise even if only as observers.” (Vega-Toscano, 1998).

Interactive actuality was not violent, there being no archaeological record of fighting (Cavalli-Sforza, 1997), the incoming AMH seeking different landscapes with different hunting strategies, different social structures to Neanderthals (Gamble, 1999). The replacement hypothesis answers questions not answered by local evolution theory (Lewis-Williams, 2002), because widespread rapid migration is faster than evolutionary change by scattered, isolated, and different Mousterian populations. Replacement was not inexorable but a series of stepwise, discrete advances, and as the Neanderthal populations contracted and retreated, coexistence was not universal (Bocquet-Appel, 2000), with isolated pockets of Neanderthals living on until extinction.

The fate of the Neanderthals during the transition has to be considered in terms of speed of change, geographical extent, and type of change – cultural versus biological. There is a need to define incoming modern behaviour, social, cognitive, symbolic and ritual in comparison to that of Neanderthals. There are also contrasting hypotheses concerning the origins of AMH themselves. No hybridisation occurred but more evidence is required to resolve the issue of acculturation and displacement.

4.  The Matter of Molecules and Genetics

Neanderthal mtDNA was sequenced at the Max Planck Institute (Hundt, 1994), where differences between European humans for the derivative haplogroup H (CRS) were studied, and which revealed the Neanderthal genome branched from humans more than 300,000 years before Haplogroup H reached Europe. With regard to genetic differences the first draft of 63% of the Neanderthal genome comprised 3.7 billion base pairs (Saey, 2009). The entire Neanderthal genome was elucidated in 2010. It transpired that some of the Neanderthal genome has more in common with chimpanzees than humans.

Following indications that Neanderthals were ‘distinct’ from us it was broadcast that scientists “…studying the DNA of Neanderthals say they can find no evidence that this ancient species ever interbred with modern humans.” (Morgan, 2011). However, humans and Neanderthals do share the FOXP2 gene variant associated with brain development and speech. In addition the study results some inbreeding between humans and Neanderthals because the genomes of non-African humans have from 1 to 4% of Neanderthal DNA.

The DNA of the Neanderthals was gleaned from fossil specimens from Croatia. Neanderthals in Europe and parts of Asia became extinct around 30,000 years ago. Modern humans left Africa circa 100,000 years ago. Neanderthals lived side by side with AMH for many thousands of years, but without evidence of interbreeding. One gene focus studied was that of microcephalin-1. The Croatian Neanderthals did harbour an ancestral form of the microcephalin-1 gene. This implies that the Neanderthals at most, contributed a very limited fraction of the total variation found in contemporary human populations. Despite a potential interaction over a long period of time, it has to be recognised that the populations concerned “…had been separate for hundreds of thousands of years and I think there would have been significant physical and behavioural differences between them.” (Stringer, 2011).

Evidence from Neanderthal mtDNA shows that they survived late in Europe and their “…per generation contribution to early modern human populations must have been fairly small (less than 0.2%) or we would find Neanderthal mtDNA lineages in living humans.” (Weaver, 2005). Sequence comparisons of human mtDNA sequences “…show that the Neanderthal sequence falls outside the variation of modern humans.” (Krings, 1997). Modern archaeology supports the theory of rapid population growth (Klein, 2004), as does living human DNA (Ingman, 2000). Neanderthal mtDNA has demonstrated a distinctiveness when compared to modern human which means “…either modern human and Neanderthal populations diverged deep in the past or human mtDNA diversity was much greater and more subdivided in the past than in the present. (Weaver, 2005). This brings us back to the evidence that the mtDNA sequence of Neanderthals “…supports the scenario in which modern humans were recently in Africa as a distinct species and replaced Neanderthals with little or no interbreeding.” (Krings,1997). The likely explanation is that the Neanderthals became extinct without donating any of their DNA to modern human populations. Finally, recent studies have clearly shown that the age of the common ancestor of Neanderthal and modern human DNA “…is estimated to be four times greater than that of the common ancestor of human DNA.” (Kings, 1997), and therefore a single “…randomly mating population of modern humans and Neanderthals is not consistent with the mtDNA evidence.” (Weaver, 2005).

5.  The Matter of Recent Analysis 

The controversy concerning possible interbreeding between Homo neanderthalsensis and Anatomically Modern Humans (AMH) which unfortunately has contained inaccurate journalistic interpretation and emotive reportage of learned articles. An example recently has been the view that it has “…been around 30,000 years since the ancestors of modern-day humans are thought to have wiped out the ancient Neanderthals.” (Pleasance, 2014). The implication is obvious – the Neanderthals were violently eliminated by incoming Cro-Magnon in Europe. There is not a shred of evidence to support this assertion. With regard to inbreeding between Neanderthals and Modern Humans many of the myths “…that plague archaeologists come from outside the profession, the product of overtly imaginative minds untrained in the scientific study of the past and unfamiliar with the archaeological evidence.” (Chase, 1987).

New DNA evidence indicates that anatomically archaic Neanderthals did not contribute greatly to the gene pool of modern populations, and therefore did not previously interbreed (Stringer, 1993; Krings, 1997; Krings, 1999). The age of the common ancestor, derived from mtDNA analysis, of Neanderthals has been estimated as four times greater than the common ancestor of human mtDNA, which suggest “…Neanderthals went extinct without contributing mtDNA to modern humans.” (Krings, 1997). Human Y chromosome studies support the view that Neanderthals made none or little contribution to the modern human gene pool (Hammer, 1995; Trishkoff, 1996). Unfortunately assertions that there are differences between non-African and African populations due to European interbreeding with Neanderthal populations can be construed as implicitly racist. In the late 1990’s research on remains recognised that the DNA of Neanderthals showed “…at least 500,000 years of evolutionary divergence between our own species and the c. 40,000 year old Neanderthal in question, diminishing the likelihood that the two species intermixed.” (Pettitt, 1999).

The expansion of pre-modern humans into east and west Europe occurred, as we know, some 40,000 years ago and this eventually “…led to the replacement of the Neanderthals by modern humans – 28,000 years ago (Golovanova, 1999). At this time a second radio-carbon analysis of Neanderthal remains them to be 29,000 years old and one of the latest specimens found (Smith, 1999), but still distinct from modern humans (Ovchinnikov, 2000). The specimen from the northern Caucasus (Ovchinnikov, 1999) was separated from the German Feldhofer cave in he Neander Valley by some 2500 kilometres (Krings, 1997; Krings, 1999). The Neanderthal skeleton from the Caucasus showed a 3.48% divergence from the Feldhofer specimen. Despite the distance both sets of remains displayed closely related mtDNA, which was distinct in phylogenetic terms from modern humans,  which provided “…further support for the hypothesis of a very low gene flow between the Neanderthals and modern humans…the data reduce the likelihood that Neanderthals contained enough mtDNA  sequence diversity to encompass modern human diversity.” (Ovchinnikov, 2000). With regard to western and eastern Neanderthals, the estimated age of the  mtDNA of the most common recent ancestor (MCRA) is between 151,000 and 352,000 years (Gamble, 1998). In terms of the palaeontological record the divergence “…of modern human and Neanderthal DNA was estimated to be between 365,000 and 853,000 years.” (Ovchinikov, 2000).

Humans replaced Neanderthals in Europe between 42,000 and 35,000 years ago but however “…no Neanderthal mitochondrial DNA (mtDNA) lineage is found to date among several thousands of Europeans…interbreeding rates as high as 25% could not be excluded between the two subspecies.” (Currat, 2004). This simulation model with its interbreeding rate of 0.1% means an admixture over some 12,000 years thus “…results complement recent genetic and morphological evidence indicating that early human and Neanderthal interbreeding was unlikely.” (PLOS, 2004). Later analysis and more current thinking “…suggests that the modern human and Neanderthal lineages diverged before the emergence of contemporary humans.” (Noonan, 2010). The evidence from fossil mtDNA strongly indicates that interbreeding did not occur between humans and Neanderthals (PLOS, 2004). The low rate of 0.1%  “…strongly suggests an almost complete sterility between Neanderthal females and modern human males, implying that the two populations were probably distinct biological species.” (Currat, 2004). A report on another study (Rincon, 2010) claiming that Neanderthal genes ‘survive in us’ claimed between 1% and 4% of Eurasian genomic structure was Neanderthal in origin. The genomes of populations of non-Africans, such as those from Europe, China, and New Guinea, were closer to Neanderthal sequences than those of African origin (Rincon, 2010), suggesting limited gene flow took place between Neanderthals and the ancestors of modern Eurasians.

The debate continued with the proposition that Europeans never actually had Neanderthals as neighbours (Pinhasi, 2011), and carbon 14 dated Neanderthal remains from the Caucasus “…suggest that the archaic species had died out before modern humans arrived.” (Callaway, 2011) the remains 100,000 years older than expected. In 2010 the genome of the Neanderthals was decoded (Green, 2010) with the implication that humans Neanderthals never met in Europe and instead “…humans departing Africa encountered resident Neanderthals in the Middle East.” (Callaway, 2011). It was claimed earlier that there was a Neanderthal settlement in Gibraltar some 24,000 years ago (Finlayson, 2006). Another source states that the last Neanderthals of southern Spain did not co-exist with modern humans (Heritage Daily, 2014), the academic opinion being that it was “…improbable that the last Neanderthals of central and soutjen Iberia would have persisted until such a late date, approximately 30,000 years ago.” (Jorda, 2010). The opinion thus was expressed that the results of DNA research therefore show “…that there was admixture at some stage in our human ancestry, but it more than likely happened quite a long time before humans arrived in Europe.” (Pinhasi, 2010).

Finally it was reported that a fifth of Neanderthal genetic code survived in modern humans but furthermore the “…last of the Neanderthals may have died out thousands of years ago, but large stretches of their genetic code live on in people today.” (Sample, 2014). This journalistic exercise was based on research concerning the resurrection of surviving Neanderthal lineages from modern human genomes. Essentially the claim was that AMH overlapped and interbred with Neanderthals to the extent “…that non-African humans inherit 1 to 3% of their genomes from Neanderthal ancestors.” (Vernot, 2014). The journalistic and somewhat exaggerated interpretation continued by stating that the traces of Neanderthals in our make up “…are the lasting legacy of sexual encounters between our direct ancestors and the Neanderthals they met when they walked out of Africa and into Eurasia about 60,000 years ago.” (Sample, 2014). Is this the whole issue. Are there other non-genetic factors that need to be considered? In other words attention has to be paid to non-biological factors that may preclude the possibility of interbreeding even if Neanderthals and modern humans had met  or co-existed. More research is not only needed into acculturation and the archaeological background but also into social and cultural factors. Interbreeding has to be considered in the light of clan exogamy, systems of taboo, ritual practices and totemic relationships between separate groups – especially if they are indeed separate sub-species. To resort to descriptions of ‘sexual encounters’ or ‘wiping out’ Neanderthals only clouds the issue. Anyway – humans share 98.8% of their DNA with the chimpanzee but there is no claim the two species ever interbred. The situation elsewhere is a commonality of 50% with banana DNA. Have we ever interbred with bananas?.

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Taboo (tabu).

The numinous refers to the attraction and awe in combination. Taboos are sets of negative rules considering things that one must not do. They are the means whereby the supernatural can be approached in a reverential, non-casual manner. The function of taboo is predominantly psychological. Taboos originate in man’s fear and respect for the supernatural. Taboo sustains the awesomeness of the supernatural and reinforces attitudes of care and mystery. Taboos act as punishment for attitudes of carelessness and profanity. Taboos are also a mechanism of separation of higher groups from lower groups, and attach reverence to the kingship and the priesthood. A violator of taboo becomes the object of communal vengeance in primitive society. An example is the violation of the law of exogamy.

There are taboos concerning birth and death. The mystery of life and death is supernatural to primitive man, and so accordingly taboos develop. The mysterious processes of the nature of reproduction are viewed with reverence and awe. From the attainment of puberty women are surrounded with innumerable taboos, particularly concerning pregnancy and childbirth. At these time the woman is sacred and therefore dangerous and possesses mystic influence. Taboos are associated with death and any person who comes in contact with a corpse is rendered taboo. This taboo is contagious and thus the prohibitions concerning death extend to the whole house, family and clan.

There are a number of taboos and rituals that are centred around the warrior. The vessels used are sacred. Continence and personal cleanliness must be observed before battle. Care must be taken to prevent the enemy obtaining anything by which they can work their magic. Blood is potent and a slayer in battle and is as dangerous as a pregnant woman. He must touch nobody and nor go near the tribe until he has performed the necessary purificatory rites.

Taboos relate to the thing feared. The supernatural is a help in trouble, but is also a source of danger and disaster if it is not handles circumspectfully and propitiated. These are acts of appeasement, atonement, conciliation and expiation. Purification takes place after visits from ancestral spirits. A crop failure is the result of a broken taboo, a matter of pollution, and unexpiated defilement. Hence the cruelty of many primitive rites. This cruelty takes the form of human sacrifices, tearing to pieces of living animals. The roots of these rites are in terror – the terror of the breach of the taboo, a terror of the forbidden thing.

With taboo and the priesthood priests, and often the king, are regarded as sacred. They are guarded against by profane things. Profane things are not sacred, they are common things. Care must be taken to prevent sacredness from being injuriously communicated to persons or objects. Priests are often required to abstain from meat, shed no blood, and not allow their hair and nails to touch commoners. Every sacred rite requires of the worshipper a similar ritual purity to that of the priest. Prior to participation there is a period of purificatory preliminaries and abstention from the forbidden things. Sacred things are temples, stones, trees, images, and objects of worship.

The concept of ritual taboo is as widespread as ritual power. Taboo is an aspect of ritual power, and rests upon the belief in the efficacy of symbols. Efficacy is the capacity to produce an effect, a mode of effecting a result. Taboos can be very effective indeed, and can discourage  theft and enhance prestige. In relation to all ritual taboo is the essential part played by reinforcement processes. Taboo reinforces values upon adherence to which the smooth running of society depends.

Taboo in Primitive Society

The Daughter of Herodias.  Public domain.

The numinous, that is the combined attitudes of both attraction and awe, has been an almost constant aspect of man’s relations with what he regards the supernatural. Taboos (tabus) are sets of negative rules, negative sanctions and prohibitions according to Margaret Mead, and interdictions in the terminology of Emile Durkheim.

The system of taboo is the non-casual and reverent manner in which the supernatural can be approached. The function of taboo is that it is predominantly psychological, originating from man’s fear of that which he does not understand. As a result taboos engender fear and respect for the supernatural, sustaining awesomeness of the supernatural. Obviously there is reinforcement of attitudes of care, and the mystery. There being punishment of attitudes of carelessness, and the profane. Taboo is also a mechanism whereby there can be a separation of social groups, for example the separation of the lower from the higher. Thus the attachment of reverence and sanctity to kingship and the priesthood. Violators of taboos become the object of communal vengeance in primitive societies, examples being found in the transgression of the laws of exogamy.

Mary Douglas developed the concept in Purity and Danger (1966) that primitive religions are inspired by fear, and that at the same time are inextricably confused with defilement and hygiene. Equating hygiene with dirt in general, dirt becomes essentially comparable with, and represents disorder. Following from this concept the elimination of dirt is not a negative act but a positive effort to organise the environment, to create order. This reordering of the environment is a creative function, a unifying experience and makes the purification of primitive society conform their idea. Whether this idea is an ‘a priori’ notion, or a reflection derived from society was not absolutely made clear. Was the ‘idea’ man’s concept of society and the supernatural? Or was the ‘idea’ the ‘supernatural’?

Mary Douglas continues by saying that rituals of purity and impurity create unity in experience. Therefore we can deduce that the symbolic patterns that are worked out and displayed have a social purpose. People therefore try to influence one another’s behaviour and beliefs, and thus reinforce and exert social pressures. Political power it was claimed is usually held precariously, but this was no exception in primitive society. Hence the legitimate pretensions of the rulers, kings and priests, were reinforced by beliefs in extraordinary powers that emanated from their persons, insignia and utterances. Here we have an example of taboos which are a reinforcement of reverence for status.

The ideal order of society is guarded by what are termed ‘ dangers’, and these dangers threaten transgressors. The danger beliefs being used as an effective means of mutual exhortation. Thus a development from this situation is that certain moral vales are upheld and certain social rules are defined by beliefs in the contagious nature of danger. These therefore pollution beliefs can be used in a dialogue, a negotiation of claims and counter-claims in status.

The ideas of separation, purification, demarcation, and the punishment of transgressions has the main aim of imposing a system on what was described as an inherently untidy experience. That these ideas exaggerate the differences between such opposite concepts as ‘within’ and ‘without’; ‘above’ and ‘below’; ‘male’ and ‘female” ‘with’ and ‘against’. Through this system of concepts of taboos there emerges a semblance of order in the society concerned. From the above the conclusion drawn was that the symbolic structures of primitive religions gave scope for the meditation and reflection on the relation of order and disorder. As well as such polarities as ‘being’ and ‘non-being’; ‘formed’ and ‘formlessness’; and ‘life’ to ‘death’.

Emile Durkheim took the view that on the origin of the word ‘taboo’, and especially in the Polynesian languages, the word was used to designate the “…institution in virtue of which certain things are withdrawn from the common use.” John Lewis defined taboo as a “…restraint or prohibition placed against certain acts, words and things, which if violated, lead to an automatic penalty inflicted by magic or religion.” Of interest to note is that taboos connected with animals or plants are related to totemism.

A more conclusive analysis of taboo was put forward by Franz Steiner. It being stated that taboo was concerned with all the social mechanisms of obedience which had ritual significance. That this was of the nature of specific and restrictive behaviour in relation to dangerous situations. Hence taboo deals with the social aspect of danger itself, being concerned with it in two main directions. Firstly, the protection of individuals in danger, and secondly, the protection of society from those endangered, that is to say, dangerous persons. About which Steiner said “…taboo is an important element in all those situations in which attitudes to values are expressed in terms of danger behaviour.”

It is restrictive behaviour which ensures the power of the charm, the charm or taboo being intended to impose on others in the interest of others for example the protection of property. Thus it is the involvement of taboos that renders danger controllable by institutionalised society. Steiner declared danger to be not a quantitative concept – to face danger being to face another power. Hence taboos narrow danger, this narrowing down having the effect of localising danger. This localisation of danger to part of and not the whole, is the function of taboo. Social relations then become describable in terms of danger, through the contagion of danger there is social participation in danger. Taboo then has two quite separate, but interdependent social functions. Firstly, the identification and classification of dangers and transgressions. Secondly, the institutionalised localisation of that which is the danger – hence protection of society.

The concept of ritual taboo is as widespread as the concept of ritual power, taboo being an aspect of ritual power. Taboo rests upon the belief, like ritual power, in the efficacy of symbols. Efficacy being the capacity to produce an effect, a mode of effecting a result. Taboos can be very effective indeed, and may be a strong deterrent or enhancement of status and prestige. In relation to all ritual taboo is an essential part of reinforcement processes. reinforcement of values upon adherence to which  the smooth running of society depends, hence the effect of taboos in the social cohesions they exert.

Human Sciences essay (1971-1974).

Stages of Human Evolution

As we know, humans make their own history – admittedly they do determine their history according to an individual whim, but according to circumstances derived from the past, in relation to the objective laws of social development. Humankind therefore have features of social life that are uniquely human and these include family structure, the fact that they have or still do live by hunting, their food-sharing, possession of a home camp. Furthermore, we can recognise other sharp delineations between humans and apes, these delineations being evidenced by qualitative breaks between the human species and all other forms, past or present, of monkeys and apes.

At this point we van envisage that at some time in the dim past of 500,000 to 1,000,000 years ago ancient hominids in the form of primitive varieties of the gens Homo appeared. Eons prior to this emergence, even more primitive hominid types had developed from the basic primate pattern. We can regard this happening, for the sake of clarity, in two stages. The first stage of hominisation took shape in the lower Pleistocene, which began about 2,000,000 years ago and merged with the middle Pleistocene some half-million years ago. The hominid representatives of this period were primitive variants of Australopithecines. These diminutive pre-men combined bipedal locomotion with an erect posture, though fossil evidence suggests a rather ore shuffling form of gait than a striding walk. Their brain capacity was small. Compared with modern man they had 600 cc in comparison with our average of 1500 cc. In so far as these various types of Australopithecines – or Southern Ape men – were concerned there is little evidence to indicate that their social organisation was much in advance of the Pleistocene apes, but they were it is now believed primitive tool makers and users.

Though they are still subject to conjecture, the Australopithecines were probably vegetarian rather than carnivorous, because it is doubtful whether they had the necessary level of social organisation to permit either organised hunting, or the weapons needed to kill large prey. Nothing precludes their scavenging from the prey of animal predators, and it is also likely that they would have foraged during the day in protective groups, but we cannot assume that they were internally organised by kinship relations. These speculations and conjectures mean that, if we are correct, the Australopithecines were only a little in advance of the chimpanzees. These Australopithecines are the first known hominid types who had developed an erect posture and had thus freed their hands for tool manipulation. Their teeth functioned as tools, despite their humanoid dental structure as opposed to that of the great ape, for eating roots and nuts and tearing natural materials. However, we can see that in these early hominids the basic rudiments of the trend towards the emergence of the ways of life exhibited by humans. The Australopithecines eventually became extinct during the lover Pleistocene era, and are today regarded by most serious anthropologists as a branch off the main evolutionary line of the hominid progression that culminated in Homo sapiens.

The second stage is found in the middle Pleistocene with the appearance of men – with large brains and much taller than the Australopithecines. I should be noted that these Australopithecine types were not directly ancestral to the middle Pleistocene hominids, but an offshoot away from the main line. The theory is that both types considered here had a common, more primitive progenitor. These middle Pleistocene hominids that had bypassed the Australopithecine blind alley, occurred about half a million years ago and are the various representatives of the ‘erectus’ species of the genus Homo. The first men!

These early men possessed and used complex tools and weapons, made from various types of stone, which they used to kill large animals and collect plants and roots. In may respects they thus led a recognisable human way of life. They had home bases and camps – many of their fossil remains being found in obviously continuously inhabited caves. It is at this period that there occurred the rapid development of the habits and modes of existence that are part of the cultural ancestry of the human species. This development in economic terms is known as the hunter-gatherer mode of life and subsistence – which became the universal mode of subsistence for the ensuing 500,000 years. The development of settled communities using cultivation, which led to the increasing complexity of human society, occurred only around 10,000 years ago.

One persistent problem concerns the stage during human evolution at which culture originated. The ‘critical point’ theory postulated that there occurred an ‘all or nothing’ quantum leap, and that the development of the capacity to acquire culture was of a sudden appearance. A ‘now you don’t  see it’ and ‘now you do see it’ concept. This particular theory argues therefore that at a certain historical moment in the progress of the hominid procession there suddenly occurred the ‘humanisation’ of a particular branch of the hominid stock. This great even was, in genetic and anatomical terms, only a minor alteration in the structure of the cerebral cortex. This suggests that the point of the appearance of Homo depends entirely on the random, chance occurrence of a mutation or mutations. This theory proceeds to outline the process in terms of a methodology. The portentous event of ‘humanisation’ is conceptualised as a ‘marginal’ quantitative change that gave rise to a radical qualitative difference, In other words this theory tries to explain each higher stage of human society as having its cause in a mutation affecting parts of the cerebral cortex. This is not quite the case however.

The critical point theory admits to the existence of leaps as the qualitative result of a series of quantitative events, but it does not seem to realise that the new qualitative stage is a higher stage. And certainly, the development of the cerebral cortex with its complex association areas and frontal development is not the result of some sudden mutation – but the qualitative result of ages of quantitative accumulations involving social labour, the use of the hand, and the formulation of symbolic signals expressed as language. Nonetheless, this theory does have some elements of reality, especially when compared to religious and idealist theories of anthropogenesis. The critical point theory claims there are three major considerations that give support to its position.

Firstly, the ‘critical point’ theorists note the enormous gulf between the mental abilities of humans and the great apes. This is certainly true, for as we know, man talks, conceptualises and makes tools. Secondly, it is shown that mankind uses a language, can think in abstractions, and can symbolise. Man has named his environment, given terms to describe and denote events, laws and matter. This is an arbitrary framework to enable man to classify, codify, and thereby modify., his environment. Further from this there has been the progress from simple reflex activity, through conditioned responses, to more complex signal behaviour which arrived eventually at conceptual thought. These processes are achieved as a series of quantum leaps, not as a result of a lineal development or continuum. Thirdly, there is the concept which has been termed the ‘psychic unity’ of mankind. This, quite truthfully, states that in regard to the living ‘races’ of mankind, no important differences in natural thought processes exist. This is supported by all the available empirical evidence from various ethnic groups. The support for the ‘psychic unity of mankind’ hypothesis is quite extensive, drawing evidence from psychology, semantics, ethnological studies, and linguistics. There is no critical brain size in relation to human intellect – palaeontological evidence proves that Neanderthals on average had larger brains than modern man. It is therefore unscientific to search for a ‘cerebral rubicon’ with regard to the relative size of the brain – it is the internal organisation of the brain that is the main criteria in determining the development of intellect.

The Australopithecines were called ‘man-apes’ and lived around 750,000 to 1,750,000 years ago in southern and eastern Africa – and what is so striking about them is their combination of both primitive and advanced anatomical features. Firstly, their pelves and bones of the lower limb exhibit a structure similar to modern man (hence the idea that they were upright and bipedal in gait). Yet, the capacity of their crania was only slightly larger than that of a gorilla. We can therefore assume that even if they were not directly ancestral to the genus Homo, they do represent an initial form in the evolutionary path that eventually arrived at sapiens man. It is generally accepted that the Australopithecines branched off from the main line of development and became extinct after failing to develop further. Additional evidence of occasional hunting and primitive implement fabrication indicates that these Australopithecines were capable of mastering some rudimentary elements of culture, and in such a ‘proto-culture’ we may be able to conclude that some form of early communication existed between them.

The ‘critical point’ viewpoint believes that the major period of cortical development followed, and did not precede, the development of culture. The ‘critical point’ theorists therefore regard man as more less complete in terms of his neural compositions before cultural development started. Therefore their view develops from the proposition that cultural expansion and improvement was occurring prior to the cessation of human organic evolution. In certain respects this is true of a number of anatomical and morphological structures, but it is not true in respect of the human intellect. The development of mans’ cerebral capacity surely arose in an inter-related and inter-dependent context of social labour and increasing technological expertise?

Why should ‘brain’ precede culture? Are we not more correct when stating that the development of mans’ brain was an inter-related process, that included the use of his hands and the development of articulate speech, in conjunction with the unique and crucial criteria of social labour? This returns us to the main flaw in the ‘critical point’ theory’s position, and that is their conception of a ‘before and after’ situation with regard to the origin of culture. In terms of millions of years we can certainly say that man is today what he was not yesterday – but can we claim that, because man developed rapidly in society, his biological evolution has ceased? Certainly we can admit that man evolved biologically further than Homo erectus who was a primitive cultured hominid. We must conclude that in reality the neurological development of man’s brain was the result of culture – it became the ‘human’ brain precisely because of social labour. Social labour of necessity requires speech and language, as well as the necessarily indispensable hands and tools.

If man makes himself, and we accept this, then we cannot agree that man had developed cortical structures of a highly specialised type with all the attendant association areas and neural ramifications, prior to requiring them or before he even knew he would need them. Man, as these theorists point out quite correctly, is not just a producer of culture and technology, he is also the product of that culture.

Up to now we have considered the biological and social evolution of modern Homo sapiens from or pre-sapient ancestors and precursors. It remains to analyse the crucial element that enabled man to become Homo sapiens, and this unique factor, which has to be understood in relation to human society, is the development of the hand and its role in social labour. It is this factor which adds to man’s uniqueness and his true nature – man evolved as a worker! We cannot try to analyse the origin and development of the human family, or attempt to appreciate its role in modern society, until we recognise mans’ origin and subsequent development in terms of labour, in terms of his production of the material conditions of life.

Man is a tool fabricating organism – his implements are intelligently organised modifications of naturally existing objects or materials. Furthermore, man’s concepts of his tools are based upon his accumulated experience and knowledge of past effects of such implements. The use of tools depends completely upon the necessary evolution of the human hand, the hand not only being itself an organ of labour but also the manipulator of tools which are ‘extensions’ of the hand. With other animals their own body extensions function as their sole implements – and as such are specialised and adapted and inseparable, usually unalterable part of the animal anatomy. Obviously this is not the case with man, whose tools are extraneous and his hand as a universal tool. The human hand is an exquisite piece of organised and sensitive anatomy compared with even that of a great ape. Only the human hand could be so well developed because unlike apes, only human hands have had the benefit of hundreds of thousands of years of determined labour to perfect them.

The hand is the ‘organ of labour’, and more especially the hand is the product of labour, but the hand did not arise on its own. Therefore we must of necessity consider the hand in relation to the material organ of thought – the brain. As has been stressed, man can foresee the future action of his implements and this underlines the fact that complete use of the hand implies an enormous level of developed intellect. One needs to see to make or use tools and this again implies the necessity of conscious thinking and conceptualisation, as well as showing that the use of implements reacts back upon man and enhances his thinking and knowledge of his environment.

We can summarise the comparative study of man and other animals. Man either excels or at least equals all other specialised species of animals and this is because other animals are adapted by natural selection to their own particular ecological niches. In this respect man is, and had to be in order to achieve his sapient state, a relatively unspecialised animal. Unlike most animals, man goes where he will or may, often accompanied by those erstwhile camp-followers – the dog, the rat, and the cockroach.

The brain of Homo sapiens has taken epochs to reach its highly evolved state – the difference between the animal and human brain is not merely one of quantitative sixe or complexity, it is at a qualitatively higher level of organisation. The human brain and its property, consciousness, is the highest form of organised matter. The human brain in terms of cells is not merely bigger, it is endowed with cerebral structures and interconnections not possessed by other animals. Examples that easily come to mind are the association areas concerned with speech and language, motor areas connected with manual dexterity and control, and the all important expanded cortical development. Mans possibilities are enhanced by the fact that his brain can make and remake, constantly, new connections and inter-connections – and it is within these patterns that we find the accumulated experience and knowledge, not only of the individual, but of the species.

Primates and Humans

The sapient species of the genus Homo has, in the course of its existence, produced many types of society. In some regions these societies have undergone rapid changes from one stage of development to another, higher stage. In other regions societies have remained static or disappeared.

It has often been mistakenly stated that primitive peoples live like most other animals, bereft of implements, possessing no language or articulate speech, and without social organisation. This is certainly nowhere near the truth and is not, and never has been, the case. Humans have congregated in groups wherever and whenever they have existed, and have, as social animals constantly striven to mould and control their  environment in order to satisfy their needs. Humans therefore make and remake their environment and, as a result of this activity in this sphere, make and remake themselves. From the original family groups there have developed various forms of social organisation and therefore, as the claim of the ‘naked ape’ brigade need to be countered, we should proceed to examine the evolution of social life with regard to the great apes and monkeys. Such an analysis will show whether in fact there is anything in common between human and ape social life.

Primate social life patterns of behaviour have certain unique and rare qualities, one of which is that primate life is essentially group life. At this juncture we must state that humans are also primates in the phylogeny of zoological classification.  There are characteristics of a special nature that differentiate primate groups from the rest  of the mammalian phylogeny. Firstly, a primate group is relatively large, averaging about 20 members usually exhibiting relationships that are stable and persistent.  There is no seasonal variation in the composition of the group, which is highly organised and contains both sexes of all ages from birth to death. However, as with certain other animal societies, the individual differences within the group are arranged according to age and sex into a hierarchy dependent on relative dominance. Such a hierarchical arrangement results in a separation of roles and statuses within the group. mong apes today, for instance, the group consists typically of a dominant male with a troop of males who are subordinate to him plus the females with their offspring. In this hierarchically organised troop there occurs o division of labour between the sexes and individuals, including the young, have to forage for their own food.

These features of the primate group, including a large size, stable membership and differentiation of roles, has led to a network of complex behavioural patterns. These complex primate social relationships have led to specialised accommodations exampled by the socialisation of infants during a long period of infancy. Inside the primate troop child rearing is a social affair and is not the sole role of the mother. With non-human primates the mothers are not separated from the rest of the group while the offspring are young, neither do the mothers live in a harem. In reality , the mothers are surrounded by all the members of the group, including the curious juveniles. All the members of the group therefore, including the young and old, are organised into a structured, functioning social system.

Amongst monkeys and apes it is the gibbons alone who live in what has been loosely described as a ‘family’. Gibbons tend to be antagonistic to each other unless they are of course living as a mating pair – but even the pairs live apart from each other. As soon as the young Gibbons reach maturity they leave their parents.

he human family always occurs as a sub-unit within a larger, more complex unit – never in isolation. The lager unit, for example, could be a tribe. Baboons and macaques are especially adapted for terrestrial life rather than the arboreal existence, and allegedly have a form of social organisation that is supposed to resemble that of their human relatives. These are the only primates with an average group size comparable to human hunter-gatherers. Hunter-gatherer communities have an average membership of fifty individuals. With macacques and and baboons the adult male and female roles differ to some degree, as they do at present in most human societies. The adult baboon male adopts the role of defending the troop, whereas the adult baboon female specialises in the rearing of the young. What becomes apparent here is that sexual dimorphic characteristics are more pronounced in terrestrial monkeys, and conversely are least developed in arboreal species.

The sexual dimorphism in adult baboons has only a morphological basis, whereas in humans there are also cultural designations for the roles of males and females. We can stress at this point that there is no biological justification for the inequalities between the sexes in human societies, because those inequalities that do exist are rooted in the class nature of society, not in our genes. In terms of biology and sociology the human family has its procreative basis in a new mating system – there has been a loss of ‘season’ at the oestrus period, the human female having adapted to the monthly period of menstruation. Monthly menstruation is an adaptation closely linked to biorhythms that are dependent on lunar cycles.

Socially there exist concepts involving exogamy, co-operation, marriage, ownership of property, and all these ideas have a concrete base in each society concerned. However, unique to the human group is the use of tools, socially organised labour, thinking, language, and the ability to plan for future events on the basis of an understanding of both past and future. Unlike animal societies or groups, all human groups have an equally long history, whereas many animal groups are only temporary transient aggregations.

It is valuable to consider a reconstruction of the life of the Pleistocene hominids because of their relevance to the later human groups in prehistory. As some anthropologists and ethologists are wont to do there is little to be gained from any unwarranted extrapolations from baboon social life to modern societies, let alone the simpler agricultural communities. In fact – human societies have little comparison with baboon or great ape groups. Unlike humans, no lasting bonds are formed between baboons, and this implies therefore that no base exists upon which to establish stable family groups. Apart from this, we must ask the critical question where is the economic basis for any ape society? Again, human groups tend to be large, stable, and generally exogamous, whereas the tendency in a baboon troop is towards inbreeding and small groups. Human families are related by marriage and kinship ties to other human families, their exogamy having an economic and social determination that makes movement of individuals within the family the exception rather than the rule.

All apes and monkeys are herbivorous and their dietary differences from humans become obvious when one compares the vegetarian baboon with the meat and plant eating hunter-gatherer. Humans are omnivorous, and humans in common with pigs, will eat anything within reason. The diet can be related to the distance travelled by a particular group, whether human tribe or a band of wandering apes. For example, arboreal monkeys have only a small area in which they forage, whereas baboons have a relatively wider range. However, the baboon troop in its entirety forages in an area far too small to provide support for one human hunter. A further example can be seen with the Australopithecines – these primitive hominids were hunters in areas that were thought to be ten times larger than areas foraged by baboons.

Human hunting varies widely with the environmental conditions, and this applies especially to the size of the hunting area. It is the possession of a camp, a home base, that enables the human group, clan or tribe to hunt and forage, thereby exploiting a large area. Such a central base is not possessed by monkeys and apes, and also their hunting of other animals is out of the question due to their movement in a troop. The base or ‘home’ of food sharing humans has no parallel in the non-human primate troops mode of existence. Whether monkey or ape, each individual member of the community has to forage for his or her own food. The female monkey does not even share food with her own offspring.

Revolutionary changes in the primate mode of existence, by the initiation of effective hunting techniques, developed only much later amongst the early upright hominids. From this point forward we are considering the process of the transition to humanity, and will be able to recognise the sharp break that delineates humans from other primates. Humans are not ‘transformed apes’. Humans are unique.

In so far as the arena of biological science is concerned there has been a tendency with some especially when studying the relationship between humans and animals, to overstress the ‘relatedness’ of humans to ‘lower’ animals. Evolution has often been mistakenly regarded as a relatively unbroken flow of lineal, biological process. Stress has been placed upon continuity, the organic world being described in the general terms of a pervasive unity. This is not the case with humans – the prehistory of our species and of other species is littered with breaks and gaps in the fossil, evolutionary and developmental record. The search for the mythical ‘missing link’ is nothing but the hunt for the ‘will o’ the wisp’ without a scientific and historical outlook. Nevertheless, there still exist anthropological theories that totally disregard the application of science to human origins. One particular form of analysis, by Richard Leakey, attempts to push back in time the supposed appearance of ‘homo’, thereby introducing a ‘religious’ concept into the study of anthropogenesis. One wonders if Leakey is on the trail of hominids or of ‘Adam and Eve’.