I argue here that all the available data on Homo sapiens (molecular, morphological, linguistic, cultural) are most readily interpreted within the framework of a phylogenetic tree that links extant human populations over a time span of no more than the last 15,000 to 20,000 years. This is not to suggest that some ur-population speaking an ur-language lived in a geographically restricted Garden of Eden 15,000 years ago, expanding out of there to lead to what we have today. Instead, the scenario envisioned here goes to quite the other extreme in envisioning our "Garden of Eden" as the entire inhabited world of that period. I suggest that as recently as perhaps 15,000 years ago the human population was something very close to "panmictic" at all levels, and that most of the interpopulational differences we observe today, and in the recent past, have accumulated since then. The proposed "panmixis" is seen as driven by the last of the glacial pulsations which would have necessitated recurrent large-scale movements of populations, not only in areas "directly" affected by the glaciers themselves, but also in those that suffered the secondary effects of shifting climatic zones and major sea level changes. It thus must have been essentially world-wide, and only after populations began to settle down in more-or-less their current areas could regional differentiation leading have begun again. Thus we would have had episodic, glacial cycle driven, regional (racial) differentiation subsequent to the expansion of Homo out of Africa, and concomitant episodic obliteration ("panmixis") of most or all of the regionality. We then simply appear to be living in one of those episodes of regional differentiation, with ours beginning with the last glacial retreat. These episodes of developing regionality would have been characterized by differential retention of portions of the existing variation (which would have been, just as today, substantial but basically intrapopulational) plus in situ developments. The degrees of past regionality achieved would, then, presumably, have been strongly correlated with the lengths of the glacial/interglacial cycles involved, and thus potentially much greater than that present today.
That is the model; what follows is its genesis, development, and testing.
GENESIS
Cavalli-Sforza, Piazza, Menozzi, and Mountain recently proposed (1988) that there is a general congruence between gene-based and language-based trees linking extant human populations. This proposal has engendered a great deal of controversy, in particular from a group of workers based at the Smithsonian (O'Grady et al, 1989; Bateman et al, 1990). Cavalli-Sforza et al have responded (1989, 1990). It seems to me that, as is so often the case in situations of this sort, the two groups have been talking past one another; and that their dialogue has had the effect, as again is so often the case, of focusing our attention, and theirs, on secondary details, and diverting it from the basic issues involved. What follows is an attempt to get at those basic issues. The most important point to recognize is that this particular dialogue is not new. The questions raised and addressed in it have long intrigued students of human evolution, and a substantial consensus as to many of the answers has been present for some time now. First, it has been self-evident since long before we had any actual gene frequency data that populations can be closer (that is, share more recent common ancestry) linguistically than genetically (for example, Native American and European-derived Spanish speakers in the New World); and also that they can be closer genetically than linguistically (for example, speakers of Austronesian and Papuan languages in New Guinea). But it has also been self-evident to most students of human evolution that such cases must be the exceptions rather than the rule, though the Smithsonian group apparently disagrees. This is evident in their more recent and comprehensive effort (Bateman et al, 1990; especially pp 8-11), and at the end of their letter to Science (O'Grady et al, 1989), where they state that:
The response to this statement has to be, "What evidence?" The Smithsonian group presents no documentary support for their position, and, indeed, it is difficult to imagine how there could be any. That is, given that any differentiation among populations (genetic, linguistic, cultural) implies actual physical separation among them, there is going to have to be an appreciable congruence among the pattern of relationships implied by each variable. Even today two populations more similar anatomically to one another than either is to a third are also much more likely to more similar genetically, culturally, and linguistically, and this would have even more often been the case in the past. Thus the position of Cavalli-Sforza et al that there is a general isomorphy of gene and language trees must be seen as something close to a null hypothesis; that is, as being much closer to being a reasonable working assumption than a data-based conclusion. This has long been evident. One of the greatest of all students of our species, A L Kroeber, pointed out many years ago that:
But the general isomorphy between language and genetic trees noted by Cavalli-Sforza et al has long been apparent, implying that "the two move together" far more often than they move separately a point Kroeber was quite clear upon:
This aspect of the Smithsonian group's argument would then have to be regarded as untenable as well as undocumented, and any attempt to validate it as very likely an exercise in futility. But such a judgment tends to deflect attention from what is very likely the real source of these objections. What has passed apparently unnoticed about the Cavalli-Sforza et al scenario is that it requires an enormous, and completely undocumented, linguistic extrapolation from the roughly 7,000 years or so over which linguists tend to agree that language relationships can be traced, to the 100,000 or so years which dates the root of their tree. While the extrapolation is enormous and undocumented (and, very likely, undocumentable even if correct), it does at first glance seem to be required by the apparent congruence of the gene and language trees in the context of the dates provided by the molecular, paleontological, and archeological evidence.
It is at this point that the fairly narrow dispute just introduced can be put into a much broader and more relevant context. We, professionals and lay public alike, have a fascination with our past. Among other things, we want to know when, where, and under what conditions, people like ourselves first appeared, and we want to know about the origins, history, extent, and functional significance of racial (or, if a less loaded term is desired, regional) variation within our species. Recent years have seen a marked resurgence of professional interest in these matters (e g, Smith and Spencer, 1984; Mellars and Stringer, 1989; and many others). That interest has spawned a number of interesting and influential hypotheses and scenarios, two of which will be addressed here.
First, there is a developing consensus as to the coexistence of two distinct Homo sapiens lineages ("Neandertals" and "anatomically modern Homo sapiens") from sometime before 100,000, to about 30,000 years ago (see Mellars and Stringer, 1989 for a recent survey of the evidence and arguments). The main problem with this scenario is that the evidence supporting it is entirely morphological; that is, there is general, though hardly unanimous, agreement that the human fossil remains of the period sort reasonably cleanly into two groups. I do not with to raise issue with that judgment at this point. My problem is with the fact that the two proposed lineages have left no record whatever of any cultural distinctiveness. We cannot identify stone-tool assemblages as deriving from "Neandertal", as compared to "anatomically modern Homo sapiens", occupations. Thus we are being asked to envision two populational (in effect, racial) lineages of one human species sharing the same stone tool cultures in the same areas and yet maintaining their genetic identities for more than 70,000 years. I suggest that absent the cultural element we could not take such a scenario seriously for any other species, and adding in the cultural element for our own species makes the scenario even less plausible. This argument is hardly novel, and yet it has clearly not been nearly enough; remaining, in the main, unaddressed and unrefuted. The
(1) presence of anatomically modern humans in sites currently dated to some 100,000 years ago in both South Africa (Klasies River) and the Near East (Qafzeh)
(2) prior to the appearance of "classic" Neandertals in Europe tens of millenia later
(3) along with the disappearance of the latter by 35,000 years ago, and
(4) the presence only of the former since
has made it impossible for most students not to see the presence of two distinct genetic lineages one connecting pre- and post-Neandertal anatomically modern humans, and the other composed of the various Neandertals. The fact of a total lack of anatomically modern humans contemporaneous with the latter has basically been ignored a manifestation, perhaps, of the "absence of evidence/ evidence of absence" problem.
The minority who would tend to accept the doubts raised in the preceding paragraph, and also to see greater anatomical continuity between Neandertals and anatomically modern humans, envision a quite different scenario. In it (generally referred to as the "regional continuity" model) Neandertals simply represent a phase connecting Homo erectus and modern Homo sapiens, so that there are appreciable, and somewhat separate, genetic continuities between non-sapiens and sapiens in different areas of the world. In this scenario, then, modern Asians, for example, are more similar genetically to Asian erectus than to African erectus. I have long been an adherent of this view (Sarich, 1971). I no longer am.
The reasons for my rejection of the "regional continuity" model are two-fold. First, it seems to me that the mitochondrial DNA data make it untenable. If regional continuity were a fact, then we should expect to see ancient, and region-specific, mitochondrial lineages (clades) in several areas of the world. But, in fact, this situation characterizes only sub-Saharan Africa (and even that is currently in doubt), and not Europe, nor the Far East, nor Australia/New Guinea (Cann, Stoneking, and Wilson, 1987).
Second, the regional continuity model would predict that the morphological distances separating the most distinct modern Homo sapiens populations from one another should be greater than those separating the latter from their "Neandertal" precursors. In other words, the morphological distance between, for example, Europeans and native Australians, should be greater than between Europeans and European Neandertals. But this is by no means the case. Using the size-corrected morphological distance metric discussed below, we find that in fact the latter distances are about twice the former. Howells (1973, 1989), using Mahalanobis distances, has obtained similar results.
This rejection of the regional continuity model should not lead to acceptance, by default, of the only apparent alternative.
I have come to see that both of the above scenarios are fundamentally flawed, and that reality lies outside the range of possibilities they represent.
I suggest here that we need to look again at the evidence, and argue, as noted in the introductory paragraph, that this second look tells us that all the available data (molecular, morphological, linguistic, and cultural) are far more readily interpretable within the framework of a tree that links extant human populations over a time span no greater than 15,000 to 20,000 years, and certainly not the 100,000 or so which characterizes so many recent discussions, including that of Cavalli-Sforza et al.
POPULATIONAL AFFINITIES OF FOSSIL Homo sapiens
The only direct evidence as to the antiquity of populational lineages resides in the fossil record, and thus I here ask it to tell us when individuals found in a given area begin to have a reasonable probability of being more similar to modern individuals found there than to those found in other areas. We might, for example, attempt to place early Upper Paleolithic European-area fossils on a tree of extant human populations derived from the data of Howells (1973, 1989). One would expect that if the 100,000 year time scale of Cavalli-Sforza et al were correct, then these 12,000 - 30,000+ year-old Europeans should fall on the European clade of the Homo sapiens tree, and the literature tends to imply that this is actually the case; in other words, that these are anatomically, as well as geographically, European that is, more closely related to modern Europeans than to modern Asians or modern Africans. That, as will be demonstrated, is simply not the case, though the demonstration is neither easy nor straightforward.
It would appear that at least three criteria must be satisfied before one can address questions of this sort with any degree of justified confidence. First, the algorithm to be used must be able to place known individuals into their appropriate populations or areas with some reasonable degree of reliability. This is obvious, for if it doesn't work reliably for knowns, there can be no rationale for using it on unknowns. Second, it should be able to take a random sample of individuals from known groups and reconstitute those groups without previous knowledge of their characteristics. In other words, our algorithm should have a reasonable robustness with respect to assessing the affinities of individuals when compared to other individuals, and not simply to known populations. This is necessary because human fossils are almost always found as individuals, and obviously do not belong to extant populations. This latter point leads to the third, and more subtle, requirement. If a fossil cannot be viewed as a member of an extant population, then it can only be tested for placement on, or proximity to, a lineage leading to one or more of the latter. But this means that a simple similarity criterion will not do, as showing that fossil X is "most similar" to extant population Y (or to individuals from Y) is without phylogenetic significance until the question of amounts of change along the various extant lineages is taken into account. That is, fossil X may be more similar to population Y than to population Z simply because less change has taken place along the Y lineage, and not because X was part of the Y lineage more recently than it was part of the Z lineage. This last problem is one that does not appear to have ever been recognized, never mind addressed, in the relevant literature; nor can it be said that the other two requirements have generally been adequately addressed or met in that literature.
Any such effort today necessarily begins with the unique and invaluable body of data gathered by Howells (1973, 1989), which he has generously made available on disk. Thus interested workers can now work directly from a large number of individual measurements made by one person on more than 2,000 skulls from, in the main, known populations. I have developed the following approach for satisfying the three criteria just noted. I make no claim here that this is the best possible "algorithm", nor am I especially satisfied with its elegance. It does, however, have the virtue of working; that is, of satisfying those 3 criteria.
There would appear to be at least 4 basic considerations here. First, which, and how many, characters are to form the basic data set ? Second, what size-correction procedure is to be used? Third, How are the size-corrected data to be compared? Fourth, how are affinities to be judged? Now there is obviously a voluminous, and often highly contentious, literature addressing each of these matters, and I will here only provide a brief justification for the choices I have made.
The measurements used here [#s 2, 4, 5, 6, 8, 9, 11, 13, 14, 17, 18, 22, 23, 24, 25, 32, 33, 35, 37, 39, 40, 41, 42, 43, 44, 45, 46, 47, 51, 54 from Howells, 1973] were chosen as (1) being the most discriminating among modern individuals and populations, (2) giving substantial attention to the face as well as the cranium, (3) less likely to be missing in the fossil specimens, and (4) more objectively measurable. Size-correction was achieved by dividing the breadth measures (#s 5, 6, 8, 9, 11, 17, 18, 22, 24) by the mean of cranial length and height; the length measures (#s 2, 23, 25, 32, 33, 51, 54) by the mean of cranial height and breadth; the height measures (#s 4, 13, 14, 35) by the mean of cranial length and breadth) and the cranial vault measures (#s 39-47) by cranial length. Then the variation in the contributions to be made by the various measures to the overall distance was reduced by converting each size-corrected measurement to a z-score (using a panel of 105 recent specimens drawn from 21 populations to provide the reference means and standard deviations). The distances (inter-individual, individual to group, or inter-group) were then calculated as the average z-score per size-corrected measurement. For this study, all 30 measurements, treated in exactly the same manner, with each contributing equally to the final result, were used for all comparisons (except, of course, when some were missing for certain of the fossils).
The next step here is to gain some measure of affinity from these size-corrected and range-adjusted data. The major factor mitigating against simply using these distances directly to reliably link single individuals with their appropriate known populations (criterion 1), or for the more difficult task of linking individuals from the same population when one doesn't know the population (criterion 2), is the fact that a morphologically "primitive" population; that is, one closer to the base of the Homo sapiens tree, would show greater affinities on the basis of shared primitive conditions, and such a result would have no phylogenetic relevance (criterion 3). The importance of this matter can be assessed by calculating the distances among Howells' 1989 sample of 29 human populations (plus the Tierra del Fuegans I measured in London and Vienna) and then seeing if any of them shows a significantly smaller average distance to the others, thus indicating much less change along its lineage. We find that the Norse, Zalavar, Hokkaido, and Ainu samples are, by this criterion, least derived, showing about 25-35% less change than the average. The Buriats (because of their combination of extreme cranial and facial breadth, and facial length) show far and away the greatest amount of change (some 75% above the average), with the Eskimo and South Australians next (about 30% above the average). This, given the lack of a tree-drawing program that does not assume anything about rates of change and can still deal with a large number of individuals, tells us quite clearly that rate-correction prior to calculation of affinities is necessary.
The simplest such procedure, given a matrix of z- scores among the units in the sample, is to calculate the correlation coefficients among the columns of z-scores. Slightly more resolving power is sometimes obtained in the situation where one is comparing against known populations by converting the z-scores to distances, and rate-adjusting each column of distances (that is, for example, reducing the Buriat distances and increasing the Norse ones). This addresses criterion 3.
These simple approaches seem to provide remarkably robust results. I set up a test sample of 50 individuals [10 from each of 5 widely-separated populations (Norse; Zulu; Tolai from New Britain; Anyang of Bronze Age China; Santa Cruz Island, California)] in Howells' sample, the 30 populations just noted, and 33 fossils. Criterion 1 was addressed using each of the approaches outlined above to compare the 50 individuals with their population means. Simply using the correlation coefficients among the columns of z-scores placed 44 of the 50 individuals into their correct population. The 6 misplacements were: one Norse marginally with the Zulu and another with the Tolai, one Zulu with the Tolai and another with the Santa Cruz, and 2 Santa Cruz with the Anyang. Using distances corrected for amount of change differences among the populations involved gave 2 marginal misplacements: the same 2 Santa Cruz were closer to the Anyang than the Santa Cruz by ~0.08 SD; and 3 no-decisions: one Norse was equidistant between Norse and Zulu, one Zulu between Zulu and Tolai, and another between Zulu and Santa Cruz. These results would appear to satisfy criterion 1 at least as well as might be desired.
Criterion 2, involving the inherently more difficult task of forming the populations without prior knowledge of their characteristics, was addressed as follows. First, the same 50 individuals were used, but the z-scores were calculated internally. Correlation coefficients were then calculated among the 50 columns of z-scores. Simple inspection gave 5 obvious units containing 37 of the 50 individuals. Means for each of those 5 units were then calculated and the remaining 13 individuals compared against them. A further 8 then fell into their correct units, 2 fell into a wrong unit (one Anyang with the Santa Cruz, and one Tolai with the Zulu), and 3 straddled 2 units (one Norse between Norse and Santa Cruz, and 2 Zulu between Zulu and Tolai). Next, the same procedure was followed using the first 25 individuals in each of two of Howells' Amerind populations, the Arikara and Santa Cruz. This time 3 Arikara fell with the Santa Cruz, and 3 Santa Cruz with the Arikara. Again, these results would appear to be more than satisfactory.
The fossil individuals (listed in Table 1) were then tested in similar fashion.
When Cromagnon through Taforalt were compared against the panel of 50 recent individuals, 4-5 were closest to the Norse, 6-7 to the Santa Cruz, 2-3 to the Zulu, 2 to the Tolai, and 1 to the Anyang. Qafzeh 6 was most similar to the Santa Cruz, Qafzeh 9 to the Zulu, and Cohuna and Upper Cave 101 to the Tolai.
When compared against the 5 modern populations using amount-of-change-corrected distances, only 2 (CroMagnon and Candide 1) were closest to the Norse, and both associations were marginal. 3 others straddled the Norse and one of the other 4 (Mladec with the Zulu, Candide 5 with the Tolai, and Afalou 10 with the Santa Cruz). 4 fell with the Tolai (Kostenki 14, the Oberkassel male, and the 2 Taforalt). 4 fell with the Santa Cruz (Pataud, Oberkassel female, one of the Candide, Afalou 32), and Chancelade and Afalou 9 went strongly with the Anyang. Predmost straddled the Tolai and Santa Cruz, and Afalou 29 was effectively equidistant from all 5.
The conclusion, then, is simple: Upper Paleolithic European-area fossils do not show any marked tendency to "look European".
This finding is reinforced by asking as to the affinities shown by the fossils to one another. The answer is that these are very similar in degree to those shown in the panel of 50 modern individuals when comparing individuals in one population to those in the other 4; that is, for example, any of the Zulu to the 40 non-Zulu. The only real, and not unexpected, exception to this pattern is that the 3 Candide individuals tended to associate relative to most of the rest.
It must be noted now that much of this is simply putting a quantitative gloss on judgments made long ago on a "look-see" basis. Various of the European-area fossils have long been seen as "Eskimoid", or "Negroid", or "Australoid" particularly when race was a far more important variable than it is today, and when the notion of "pure races" was still more or less viable. But that scenario would have proto-Africans, proto-Asians, proto-Europeans, and proto-Melanesians, all co-existing as distinct populations some 15, 000 to 35,000 years ago in one tiny corner of the world during the height of the last glacial. No modern scholar could seriously entertain such a view, but its rejection explains neither the degree of cranial and facial variation present nor the apparent affinities with diverse modern populations.
What does, I argue, is the scenario outlined in the opening paragraph of this article. Obviously the major feature of that scenario is that the regional ("racial") differentiation which has resulted in the varieties of humans populating the Earth today must be very recent; that it is, in the main, the result of changes which have occurred over the last 10-15 000 years. This would suggest that the human face and cranium are remarkably plastic with respect, one supposes, to local conditions thus we can get the remarkable, presumably convergent, similarities between the Moriori (from the Chatham Islands just east of New Zealand) and the Arikara, as well as those between Peruvians and Europeans; as well as very rapid differentiation. For example, the most distinct (in a "primitive" direction) of all recent Homo sapiens were, almost certainly, the Ona (Selk'nam) of Tierra del Fuego (Gusinde, 1939). I recently had the opportunity to obtain measurements on some 30 putatively Ona and Alakaluf specimens in London and Vienna, and the resulting distances between them and the Arikara and Santa Cruz can be larger than those between, for example, some European and African populations. This then gives one some sense of how rapidly the evolutionary process one can produce "interracial" distances among human populations, given that the Tierra del Fugean to Arikara/Santa Cruz distances have arisen over less than (possibly much less than) 10,000 years; thus there is no reason to require much more time to produce the total range of cranial and facial variation we see today within our species.
Finally, in the fossil realm, it might be appropriate to consider what light these exercises shed on the "Neandertal question". In the current consensus, as already noted, the Neandertals are seen as part of a lineage separate from that to which all anatomically modern Homo sapiens, from Qafzeh onward, belong. The basic reason for this is that they are judged as "too different", a judgment only rarely supported by actual data. Now it is true that, using the metric described above, one does find the morphological distances between the Neandertals and ourselves to be substantially greater (actually, they are, on the average, about twice as large) than those separating most pairs of extant human populations. But while true, it may not be especially germane in light of the fact that it tends to ignore both the amounts of time available to produce the observed differentiation and the range of morphological distances separating extant human populations. First, it has to be noted that the various Neandertal specimens compared here are by no means anywhere near to equally distant from the various extant populations in our comparison sample. They (except for Shanidar which is pretty much equidistant among Norse, Zulu, and Santa Cruz), Skhul 5 and Irhoud 1, as well as earlier specimens like Kabwe, Petralona, and Steinheim, are much more similar (the mean difference is about 0.5 SD; e.g., Ferrassie to Norse = 1.64 SD; to Santa Cruz = 1.23 SD) to, in particular, the Santa Cruz and Tierra del Fuegan populations than to other moderns. In addition, it is quite possible to exceed Neandertal-modern distances within the modern sample and this is without appealing to exceptional individuals. That this point has not really been made previously is likely due to the fact that the largest modern differences do not involve "more primitive" populations; that is, ones who are more like the Neandertals, but in fact are between the Buriats and Teita, where the mean pair-wise non-rate-corrected distance between 54 Buriats and 32 Teita is 1.47 SD. This compares to 1.26, 1.32, and 1.50 between Ferrassie and, respectively, 15 Moriori, 24 Tierra del Fuegans, and 23 Norse. Given figures such as these, it is difficult to see why the Neandertals can't be seen as just another regional variant ("race") of Homo sapiens, and why the term "anatomically modern Homo sapiens" should be retained at all. These numbers would suggest that there is no better reason for excluding the Neandertals from "anatomically modern Homo sapiens" than there would be for doing the same to the Buriats.
THE LINGUISTIC EVIDENCE
A similar scenario would also appear to apply in the linguistic realm, but to see it we first need to challenge the extremely conservative current consensus among most linguists that relationships among languages that diverged more than perhaps 7,000 - 8,000 years ago are, at present, unknowable. A simple exercise suffices here to show that this consensus is unreasonably pessimistic. One simply sits down with, for example, Buck's A Dictionary of Selected Synonyms in the Principal Indo-European Languages, a basic word list, and some independent knowledge of two or more languages representing distinct Indo-European groups. I used English and Croatian, representing, respectively, its Germanic and Slavic branches. If one then asks what proportion of the words in modern Croatian appear, simply by inspection (but allowing for some phonetic and semantic drift), to be cognate with the reconstructed Proto-Indo-European (PIE) form (or, where that is unavailable, with the English word), one gets a minimum figure of about 60%. For example, snow, snjeg, *sneigwh; many, mnogo, *monogho; blood, krv, *kru; tree/wood, drvo, *dru; earth, zemlja, *ghem. Similar results were obtained using native speakers of Spanish and Bengali, and for Armenian and Albanian using Decsy's The Indo-European Protolanguage: a Computational Reconstruction. Thus 60% survival seems to be a reasonably representative figure for the survival of PIE roots with meanings in extant Indo-European languages.
Now obviously some number of these matches will be coincidental (though that number will likely be small, as illustrated by the fact that Chinese, by the same test, will show less than 10% apparent "cognacy" with PIE, English, or Croatian I am indebted to Dr W S-Y Wang for this comparison), but, by the same token, some will be missed when the degree of phonetic or semantic change makes cognacy less than obvious. For example foot, noga, *ped where one might miss the English correspondence because of the phonetic changes, and would (and, perhaps, should) certainly miss the Croatian unless one remembered that "pod" in Croatian means under, and that an association between "under" and "foot" is perfectly reasonable. This would imply a cognacy loss of less than 10% per millenium along a lineage, implying that even at a time depth of 12,000 - 14,000 years; that is, twice the probable time which separates modern Croatian from its Proto-Indo-European ancestor, one might retain 30% or so phonetic/semantic cognacy. Thus one could recognize relationships among languages whose common ancestor lay that far in the past provided one looked at a sufficient number of them, and avoided simple binary comparisons. That is, if each of two descendant languages retains 30% cognacy with the ancestral language, they will, on the average, share only 9% [(0.3)2] with one another and this gets into the chance area of similarity. On the other hand, if you look at 10 such languages, three, on the average, will retain a particular cognate greatly increasing your chances of recognizing relationships among them, and of reconstructing the ancestral form. This is the procedure and argument of Greenberg [(1987) see also discussion in Ruhlen (1987)], and, whatever the questions that might be raised about certain details, there can be no doubt the current general consensus among most linguists that relationships among languages older than about 7,000 years are, at present, unknowable, is unrealistically and unreasonably pessimistic and conservative.
This frustrating unreasonableness (more fairly, obstinacy) is currently best illustrated by the controversy surrounding Greenberg's 1987 proposal that all New World languages other than those belonging to the Na-Dene and Eskimo/Aleut families have a single origin in proto-Amerind. The degree of venom this proposal has generated is best exemplified in the title of Matisoff's 1990 Language "discussion note": On megalocomparison. The reference is then obviously to the supposed megalomania implicit in Greenberg's proposal; and any doubt as to Matisoff's meaning is removed in footnote 5 on pg 108, where he writes:
The "note" then further degenerates over the next dozen pages. But Matisoff's comments are notable only for their level of petty sophomoric bitchiness, and are really beneath contempt; the message itself is representative. Yet the logical content of the various published objections is essentially nil. The main one seems to be that Greenberg has gone about it backwards; that is, instead of proceeding from lower to higher level groupings, he has simply carried out multilateral comparisons, asking whether a particular gloss has sufficiently similar reflexes in languages taken from two or more major groupings. But the response here is that Greenberg is doing precisely what was done to achieve the recognition of every other language taxon, including Indo-European itself. This is an indisputable fact, and therefore any suggestion that Greenberg, or anyone else, should go about it in the reverse direction is totally irrational.
Next, and far more important, is the fact that the marked similarities among Amerindian languages which led to Greenberg's proposal of the existence of a proto-Amerind have been recognized for a long time, and it is interesting and instructive to see what some of Greenberg's critics have made of these. Two of the latter, Lyle Campbell and Terence Kaufman, have called them (for example, first person singular /n/, second person singular /m/) "pan-Americanisms" (1980), but what are "pan-Americanisms" but cognates by any other name? In other words, common ancestry is always the simplest (in Occam's sense, requiring fewer events) explanation, and is to be rejected only when the evidence requires it. But clearly many of Greenberg's critics do not recognize this basic tenet of science. Bright (1984: 25) is representative:
"I would not be opposed to a hypothesis that the majority of recognized genetic families of American Indian languages must have had relationships of multilingualism and intense linguistic diffusion during a remote period of time, perhaps in the age when they were crossing the Bering Strait from Siberia to Alaska. We can imagine that the so-called pan-Americanisms in American Indian languages, which have attracted so much attention from 'super-groupers' like Greenberg, may have originated in that period."
A similar point was made by Levine in his 1979 doctoral dissertation on the position of Haida (pg 11):
Levine's removal of Haida from Na-Dene is then quoted approvingly by Greenberg's critics as a specific example of the failure of his approach.
But note that both Bright and Levine seemingly go out of their way to highlight the inherent flaw in their arguments. Bright writes of "multilingualism and intense linguistic diffusion", and Levine of "extremely prolonged contact". In other words, it isn't a small number of similarities that link Haida with the other Na-dene languages, and the many Amerindian languages with one another otherwise why the use of "intense" and "extremely prolonged" those similarities must be many and obvious, as Greenberg and Ruhlen keep emphasizing, seemingly to no avail. And if they are there, then specific evidence of their resulting from diffusion has to be presented; otherwise retention from common ancestry is the only acceptable explanation.
The extent to which they are in fact there is perhaps best illustrated by reference to an exchange in the pages of the American Anthropologist between Witkowski and Brown, on the one hand, and two of Greenberg's severest critics, Campbell and Kaufman, on the other, concerning the relationship, or lack thereof, between two language groups of southern Mexico and Central America, Mayan and Mixe-Zoquean. Witkowski and Brown, in their original article (1978), presented 62 putative cognate sets linking the two groups. Campbell and Kaufman, in their first rejoinder, rejected all of these for various reasons, including 14 as being "so-called pan-americanisms". They state (1980: 853):
Greenberg lists many more (entries 120 and 156 in his dictionary). Thus there is no argument about the nature of the evidence. The fact of widespread forms is not in dispute. And they can be truly widespread: Chumash is from southern California, Tehuelche is southern Patagonian. Nor are Campbell and Kaufman wrong in their argument concerning the applicability of such widespread forms to the question of the reality of a Mayan/Mixe-Zoquean grouping. If they are "primitive" for the Americas, then they cannot be "derived" for a Mayan/Mixe-Zoquean clade. But Campbell and Kaufman cannot have it both ways. If "pan-americanisms" cannot be used to define subgroupings within the Americas, they must, by the same token, be part of some larger unit; that is, "pan-American" (Greenberg's Amerind). And what is often overlooked in this example is the fact that Brown and Witkowski limited their analysis to words using velars; that is, the initial sounds in "can" and "go". These are then some small set of the total Mayan and Mixe-Zoquean vocabularies, meaning that the actual number of "pan-americanisms" to be discovered by surveying more broadly geographically, phonetically, and semantically, as Greenberg has done, must be very large indeed.
The same conclusion is reached through applying the Indo-European calibration discussed above to the American situation. If we assume that there was no human occupation of the Americas prior to ~11,000-12,000 years ago, that proto-Amerind is real (that is, was spoken by the populations that initially colonized the Americas), and rates of loss of phonetic and semantic cognacy of 7-10% per 1000 years, then we would expect that, on the average, a given proto-Amerind term would have a 30-40% chance of retaining sufficient phonetic and semantic form to be recognizable in an extant Amerind language. Given the enormous diversity of known Amerind languages, then, it would appear very likely that a large proportion of the basic proto-Amerind vocabulary should be readily recoverable from surveys of the former especially if we avoid the naysaying temptation to require precise reconstruction, and are satisfied, at least at the beginning, with "something like".
I reemphasize here the fact that a scientist must choose a common ancestry explanation unless there is specific evidence against it. Thus when Campbell and Kaufman, in their second rejoinder to Witkowski and Brown, state (1983: 365-6):
their words make it clear that whatever it is that they are doing, it isn't science though, it has to be noted here, it is, for much of recent American Indian linguistics, a perfectly representative statement. Yet consider how much illogic it exhibits in so few words. Campbell and Kaufman write, apparently oblivious to the import of their words, of "the legitimate practice in the investigation of remote relationships in the Americas of avoiding widespread forms." How remarkably convenient if you don't like the conclusion, then just rid yourself of the only data which could possibly lead to it. What, one wonders, would they say about a zoologist who wrote of "the legitimate practice in the investigation of remote relationships among organisms of avoiding certain widespread forms such as the presence of feathers, hair, tetrapod limbs, or amniotic eggs"? How else are "remote relationships" to be investigated other than by documenting "widespread forms"? Then they tell us that these "widely shared similarities may be due to onomatopoeia, sound symbolism, perhaps diffusion, accident, or other undetermined factors." Well, yes, so they might indeed, we can be quite certain that all of these, including the "undetermined" ones, will have been involved, to some extent, in producing linguistic "similarities". But the critical point here is that, in the absence of written records, there is no possible way of isolating and identifying those similarities resulting from "onomatopoeia, etc" until one has developed the phylogenetic tree linking the languages under study. What that tree cannot explain, and there will always be a good deal that it cannot, is then to be looked at for evidence of "onomatopoeia, etc." But it is obviously and inherently true that any similarity could be "explained" by appealing to these other factors. It is just as obviously true that this is not the case for phylogenetic explanations. The latter are falsifiable; the former are not or, more fairly, they are not until we have the tree of relationships. That most linguists writing on the subject refuse to take cognizance of these elementary tenets of the scientific enterprise is perhaps the most frustrating aspect of contemporary "discussions" concerning language relationships.
It also needs to be recognized that there is no good reason to believe that the distinction between intra-family and more distant relationships among languages represents any more of a real discontinuity with respect to linguistic differentiation than would that between, say, intra- and inter-generic relationships in the world of organisms. In other words, the apparent discontinuities are artifacts of our system of classification, deriving from the vagaries of human thought and language which see categories as necessarily discontinuous. That they are artifacts becomes obvious if one simply thinks about color or age, where categories and continuity are dual realities. This tendency is most readily exemplified in horizontal classifications (red, yellow; old, young), but clearly is also present for vertical ones (the taxonomy of organisms). Thus if intra-family relationships among languages have an average time depth of perhaps 7,000 years, language families might begin to group into stocks only a little further back in time, and it should take no more than 2 further classificatory "steps" to tie together all languages (Greenberg, for example, recognizes only a further 14 groupings about equal in overall diversity to Amerind). There is therefore no reason at present to think that this would require a time depth of more than 15,000 years, and this logic, along with that in the previous paragraph, provides a scenario that makes recent attempts to reconstruct etymologies linking widely separated language groups for example, Na-Dene and Caucasian, or Northern Nostratic (Indo-European, Uralic/Altaic, Korean/Japanese, Eskimo/Aleut, Amerind) much more reasonable and respectable.
I do, however, append one caveat here. While it remains very likely that the search for a proto-Indo-European "homeland" is a reasonable one; that is, there probably was a homeland in the sense of PIE being spoken by a real population narrowly circumscribed in space and time, any such notion for Nostratic, Eurasian, Na-Dene/Sino-Tibetan/Caucasian, or other such high-level groupings, is much less realistic. In other words, the scenario proposed in this article would require that one such as that Trubetskoy (1939) proposed for Indo-European:
would in fact apply to some or all of the various recently proposed higher-level groupings though likely not, as just noted, for PIE itself.
THE MITOCHONDRIAL DNA EVIDENCE
In the last decade, it has become increasingly evident that a vast and critically important body of evidence concerning phylogenetic relationships among organisms occurs in the form of their mitochondrial DNA sequences. The late Allan Wilson and his colleagues at the University of California at Berkeley have been major innovators in, and contributors to, this effort, in particular with respect to ape and human evolution. Their basic conclusion that all extant human mitochondrial DNA sequences ultimately derive from a single female who lived in Africa some 200,000 years ago has been especially influential on both lay and scientific thinking about the evolution of Homo sapiens and of various populations within our species. The mtDNA data have, as noted above, been generally, and I believe correctly, accepted as sounding a death knell to what had in recent years come to be called the multiregional (or regional continuity) model of evolution within Homo. The reason is that there is little in the way of geographical integrity in the data; that is, there is little or no tendency of populations living in areas with a long record of human occupation, say Europeans, to fall into clades containing only Europeans. In this latter respect, of course, the mtDNA data conform to the general pattern of genetic diversity in our species where there is only a small increase in genetic distances between individuals when going from intra- to interpopulational comparisons. They are also, in this sense, consistent with the scenario developed thus far in this paper.
But, obviously, the notion that all extant human mitochondrial sequences ultimately derive from a single female who lived in Africa some 200,000 years ago date, or anything like it, is not. Nor are its implications for dating within-Homo sapiens relationships. These lacks of fit, given that I couldnUt explain them, have long served to delay the formal appearance of this paper. Something was wrong somewhere, but neither I, nor anyone else, was at all clear as to just what it was for some 10 years after the appearance of CannUs 1982 doctoral dissertation. That dissertation is the ultimate source of the out-of-Africa 200,000 years ago scenario. It is now becoming clear that the scenario is fundamentally flawed, and it is fair to say that we including, of course, this writer, should have seen how a long time ago.
The reason seems, by hindsight, straightforward. Even in CannUs pioneering effort it was already evident that mtDNA evolution was, in one very important regard, producing results seriously at variance with those characterizing virtually all other molecular data sets. This was the very high level of homoplasy (parallelisms and convergences) present at minimal levels of differentiation. Thus Cann has to postulate some 378 actual mutations in her best tree (where the root is at ~0.6% sequence difference) to account for the 162 differences she was actually able to observe. In other words, each difference appeared, on the average, and with a very high variance, some 2.3 times in the phylogenetic tree linking the 110 individual sequences with which she was working. This was true even when she performed analyses using small subsets of her data. For example, a typical result has 24 differences requiring a tree containing 63 mutations to account for them (Cann, 1982, Fig. 32).
Thus a new mutation was more likely to occur at one of the 20 or so sites where one had already occurred than at the roughly 1500 where one had not!
In other words, some small subset of sites is accumulating mutations at perhaps a 100 times the rate of the rest of them. So it now looks and should have, but didnUt, in 1982 that there is a small number of hypervariable sites in the mtDNA sequence. That this might be so was originally suggested by Kocher and Wilson (1991), and reinforced by Ward and Hasegawa at a Berkeley Workshop on Human Mitochondrial DNA (4 April 1992), and by Wakely and Meacham of the University of California at Berkeley in personal discussions.
At these proposed hypervariable sites the bases which could appear [within the limitation that transitions (purine to purine, or pyrimidine to pyrimidine) are far more likely than transversions (purine<-->pyrimidine)] would randomize; for example, an original adenine would quickly just as likely become a guanine in various descendant lineages, and the position would contribute only noise to any subsequent phylogenetic analyses. Such positions would then comprise an increasing proportion of the overall amount of observed difference as one went to more closely related individuals, and fatally compromise any attempts to calculate within-human divergence times based on that between the human and chimpanzee lineages. All we can be reasonably certain of is that the actual base of the human mtDNA tree is much older than the 200,000 or so years given by Cann, Stoneking, and Wilson in their landmark 1987 Nature article. The only published suggestion as to just how much older is by Wills (1993: 53-4):
But what has really concerned us here have been the dates for the other end of the human time scale. It is that aspect of the mtDNA data, resulting from a quite logical approach to dating the root of the human mtDNA tree developed by Stoneking and Wilson, has long been at apparent variance with the scenario proposed in this contribution. In it they used a human population with a reasonably well-dated and relatively recent origin, and then assessed the levels of in situ sequence differentiation for the more rapidly evolving control region. They argued as follows. If one could date the entry of some human population into a previously unoccupied area, then the level of in situ differentiation observed among modern humans in that area would give us the rate of mtDNA change over that period of time. This calibration could then be used to calculate the dates of other nodes in the overall human tree. The original study (Stoneking, Bhatia, and Wilson, 1986) used data from New Guinea, and placed an upper limit (based on archeological evidence) on within-New Guinea differentiation of about 50,000 years. The corresponding depth of the New Guinea-specific mtDNA clades (~0.7% sequence difference) turned out to be about one-quarter of the that at the base of overall human tree (~3% sequence difference). This put the root of the human tree at ~200,000 years ago (that is, 0.7/3.0x50,000), a date consistent with one obtained by calibrating in the other direction against the human-chimpanzee distance (but, as noted above, a distance we now know to be seriously in error). This internal consistency, though interesting, cannot, however, logically validate both the starting assumption and conclusion. Once that is recognized, we can look with a more critical at the more recent results from two other areas of the world as well as New Guinea.
Stoneking et al (1992) report that most of their 41 Papua New Guinea mtDNA types fall into 3 PNG-specific clades, each of which shows internal differentiation beginning at a sequence difference of ~0.7%. It is thus of appreciable interest that DiRienzo and Wilson (1991) reported a similar pattern from their study of Sardinian and Middle Eastern individuals; that is, most of the branches in their tree originated in a "narrow interval of sequence divergence about two-thirds of the way from the root to the tips of the tree." And the "peak at the 0.5-0.75 level of percent sequence divergence suggests that the probability of survival of new mtDNA lineages changed dramatically during the evolution of modern humans." Ward (1991, 1992) reports an almost identical situation for Native Americans, with internal in situ differentiation again beginning at ~0.7% sequence difference. That these 3 instances of markedly increased likelihood of survival of mtDNA lineages, most probably due to rapid population increases, date to about the same level of sequence divergence is surely intriguing. But why do we find such temporal synchrony for events about as distant from one another as possible geographically?
For the New World, at least, there can be little doubt as to the cause here 0.7% sequence divergence dates the enormous expansion of the ancestors of Native American populations as they colonized virgin territory. Nor can there be any real doubt as to the date of this expansion. Whatever might be the final fate of claims of pre-Clovis occupations in the Americas, the fact is that any such are at most very few in number, while there are hundreds of Clovis sites spread from California to New York and all the well-dated ones fall in a very narrow interval of time (~11.0-11.5kya) (Haynes, 1992). This is then the first DOCUMENTED major expansion of Amerind populations, and presumably dates the Amerind-specific mtDNA clades reported by Ward.
For the Middle East and New Guinea, where we can be certain that the entries of Homo sapiens on the scene were much earlier than 11,000 or so years ago, another cause (or causes) is required and also readily at hand. The requisite and well-documented population-increasing innovation in those two areas broadly contemporary with the expansion of early Native Americans is obviously agriculture. Thus it is the Native Americans who fulfill the requirements of the original Stoneking/Bhatia/Wilson approach, while in Papua New Guinea and the Middle East the number of mtDNA clades representing the much older occupations by hunter-gatherer humans would be very small in comparison to those deriving from the huge increase in human populations that agriculture led to.
This then does away with the apparent disparities between the published mtDNA dates for recent evolution among certain Homo sapiens populations and those advocated in this contribution. The relative lack of geographical integrity in the overall trees, however, remains consistent with the idea of large scale, glacial-cycle-mediated, population movements characterizing much of the history of our genus subsequent to its exodus out of Africa. These would then, I believe, tend to render the search for the geographical origin of the "mitochondrial Eve" a pointless exercise, and make her a statistical artefact of no biological significance.
THE SIGNIFICANCE OF RACE
Wills, in the last paragraph of the quote provided above, raises an issue that should not be ignored, for it certainly will not be ignored, whether implicitly or explicitly, in any discussion of the topics of concern here. He argues that:
He is correct in this insofar as history is concerned. The furor which erupted around the publication of CoonUs Origin of Races in 1962 took on precisely this aura but it took it on not because the multiple-origins model is inherently more racist, but because Coon made it so. The basic thesis, in his words, is:
<..... in essence, that at the beginning of our record, over half a million years ago, man was a single species, Homo erectus, perhaps already divided into five geographic races or subspecies. Homo erectus then gradually evolved into Homo sapiens at different times, as each subspecies, living in its own territory, passed a critical threshold from a more brutal to a more sapient state, by one genetic process or another. (pg 658)
Note here that the various erectus subspecies are seen as having passed their respective critical thresholds on the way to sapiensat different times. Now add in the notion that the length of time in the sapiens grade will likely have something to do with how sapient you are, which Coon does, and the racism becomes apparent.
But, as the late Glynn Isaac pointed out to me in a Berkeley seminar many years ago, it is the Garden of Eden model (I prefer the term Garden of Eden to NoahUs Ark for two reasons: First, and more trivially, I coined it in my 1971 article; second, and far more important, it is much more congruent with the scenario it purports to characterize.), not that of multiple origins, which makes racial differences more significant functionally. It does so because the amount of time involved in the raciation process is much smaller, while, obviously, the degree of racial differentiation is a fixed quantity, and, it needs to be noted here, at the level of morphology, apparently much larger than for any other mammalian species. The shorter the period of time required to produce a given amount of morphological difference, the more selectively/adaptively/functionally important those differences become. The Garden of Eden model in its earlier formulations envisioned perhaps 40,000 years for raciation within anatomically modern Homo sapiens; the current formulations would at least triple that figure, and, thus, reduce the implied significance of racial differences. Obviously the model I argue for in this article would increase that significance well beyond anything contemplated in recent years.
BACK TO LINGUISTICS
The scenario just developed has a strong language origins/evolution corollary at each end of the time span with which we might be concerned here; that is, the time span of Homo. Pushing our mitochondrial REveS much further back in time markedly increases the likelihood that the human mitochondrial tree does in fact trace our exodus from Africa, but it would then be that of Homo erectus some million or so years ago, and not that of Homo sapiens at a much later time. It also then pretty much puts to rest any suggestions of an association of language origins (or Rlanguage as we know itS) with the origins of our species.
But it is of course the other end of our time span that is of particular concern here. While the repeated mixing of human populations proposed in this paper would render futile any attempts to trace language lineages back before the last mixing, it by the same token would argue that known human lexicons are far more strongly linked to one another than anyone to date has been willing to contemplate. This increased likelihood of genetic relationship among the worldUs known languages would imply that any ultimate reconstructive efforts would have a great deal more to work with, and, therefore, be much more likely to succeed, than would otherwise be the case. Just how far such efforts might get cannot, of course, be determined other than in practice. I look forward to that practice.
CONCLUSIONS
I have argued here that neither of the two scenarios/models, "regional continuity" and "Garden of Eden", within which the debate concerning the origins and diversification of "anatomically modern Homo sapiens" has been carried out throughout this century, can reasonably accommodate the various lines of evidence bearing on the questions involved. I suggest that we need to factor into our thinking, in particular, the effects of glacial movements on human populations, and to recognize that, when this is done, the time scale which characterizes the development of existing interpopulational variation in our species becomes markedly removed from, and much younger than, that which characterizes the evolution of the species itself. The resulting scenario would then allow us to resolve most of the serious remaining issues in these realms. The "Neandertal problem" disappears. The significance of the fossil record for "anatomically modern Homo sapiens" takes on a very different guise. Historical linguistics is put on a much firmer and more realistic foundation. The muddled mtDNA picture suddenly clarifies.
These are, obviously, very large claims. But each has the virtue that it is readily testable. Now all we need is the testing.
ACKNOWLEDGEMENTS
I thank W W Howells and C Stringer for making available the measurements for the modern and fossil specimens, respectively; and the latter and H Kritscher of the Naturhistorisches Museum, Vienna, for allowing me to study the Tierra del Fugean material in their collections. W Wang wrote a distance program and T Schoenemann one to allow direct access to the data of Howells both in True Basic. All statistical analyses were carried out on a MacIntosh IIsi using Statview. S Anton asked a critical question in a Berkeley seminar which identified for me the fundamental issue involved in assigning individuals to their correct populations. C Stringer and T White provided particularly useful discussion and commentary.
REFERENCES R. Bateman, I. Goddard, R. O'Grady, V. A. Funk, R. Mooi, W. J. Kress, P. Cannell, Current Anthropology 31:1-24 (1990).
W. Bright, American Indian Linguistics and Literature, Mouton, Berlin and New York, 1984.
C. D. Buck, A Dictionary of Selected Synonyms in the Principal Indo-European Languages: a Contribution to the History of Ideas, University of Chicago Press, 1949.
L. Campbell and T. Kaufman, On mesoamerican linguistics, American Anthropologist 82:850-857 (1980).
___________ Mesoamerican historical linguistics and distant genetic relationship: getting it straight, ibid 85:362-372 (1983).
R. Cann, The Evolution of Human Mitochondrial DNA, unpublished Ph.D. dissertation, University of California at Berkeley, 1982. The search for Eve, Science 256:79 (1992).
R. L. Cann, M. Stoneking, A. C. Wilson, Mitochondrial DNA and human evolution. Nature 325:31-35 (1987).
L. L. Cavalli-Sforza, A. Piazza, P. Menozzi, J. Mountain, Reconstruction of human evolution: Bringing together genetic, archeological, and linguistic data. Proc. Nat. Acad. Sci. U.S.A. 85: 6002-6005 (1988).
L. L. Cavalli-Sforza, A. Piazza, P. Menozzi, J. Mountain, Science 244: 1128-1129 (1989).
L. L. Cavalli-Sforza, A. Piazza, P. Menozzi, J. Mountain, Curr. Anthro. 31: 18-18 (1990).
G. D_csy, The Indo-European Language: a Computational Reconstruction, Eurolingua, P.O. Box 101, Bloomington, Indiana, 47402-0101 (1991).
A. Di Rienzo, A. C. Wilson, Branching pattern in the evolutionary tree for human mitochondrial DNA, Proc. Nat. Acad. Sci. USA 88:1597-1601 (1991).
J. H. Greenberg, Language in the Americas, Stanford University Press, 1987.
M. Gusinde, Die Feuerlander Indianer, Verlag ANTHROPOS, Wien, 1939.
C. V. Haynes, Jr. Contributions of radiocarbon dating to the geochronology of the peopling of the New World, in Radiocarbon After Four Decades, A. Long and R. S. Kra, eds., Springer-Verlag, New York,1992.
W. W. Howells, Cranial Variation in Man, Papers of the Peabody Museum of Archaeology and Ethnology, Harvard University, Cambridge, Mass, Volume 67, (1973); Skull Shapes and the Map, ibid, Volume 79, (1989).
T. D. Kocher and A. C. Wilson, Sequence evolution of mitochondrial DNA in humans and chimpanzees: control region and a protein-coding region. in Evolution of Life Fossils, Molecules, and Culture, S. Osawa and T. Honjo, eds. Springer-Verlag, Tokyo (1991). pp 391-413.
A. L. Kroeber, Anthropology (Harcourt, Brace and Company, New York, 1948).
R. D. Levine, The Skidegate Dialect of Haida, unpublished Ph.D. dissertation, Columbia University, 1977.
J. A. Matisoff, On megalocomparison, Language 66:107-120 (1990).
P. Mellars and C. B. Stringer, eds., The Human Revolution: behavioural and biological perspectives on the origin of modern humans, Princeton University Press, 1989.
R. T. O'Grady, I. Goddard, R. M. Bateman, W. A. DiMichelle, V. A. Funk, W. J. Kress, R. Mooi, P. F. Cannell, Science 243:1651 (1989).
M. Ruhlen, A Guide to the World's Languages Volume 1: Classification, Stanford University Press, 1987.
V. M. Sarich, Human variation in an evolutionary perspective, in Background for Man, P. Dolhinow and V. Sarich, eds, Little Brown, Boston, 1971, pp 182-191.
F. H. Smith and F. Spencer, eds., The Origins of Modern Humans: A World Survey of the Fossil Evidence, Liss, New York, 1984.
M. Stoneking, K. Bhatia, A.C. Wilson, Rate of sequence divergence estimated from restriction maps of mitochondrial DNAs from Papua New Guinea, Cold Springs Harbor Symposia in Quantitative Biology 51:433-439 (1986).
M. Stoneking, S.T. Sherry, A.J. Redd, L. Vigilant, New approaches to dating suggest a recent date for the human mtDNA ancestor, Philosophical Transactions of the Royal Society London B 337:167-175 (1992).
N. S. Trubetskoy, Gedanken uber das Indogermanproblem, Acta Linguistica 1:81-89 (1939). Translation from C. Renfrew, Archeology and Language, Jonathan Cape, London, 1987, pg. 108.
R. H. Ward, On the age of our mitochondrial ancestors: Evidence for deep lineages in "Mongoloid populations". American Journal of Physical Anthropology Supplement 12:180-181 (1991).
C. Wills, The Runaway Brain, Basic Books, 1993.
S. R. Witkowski and C. H. Brown, Mesoamerican: A Proposed Language Phylum, American Anthropologist 80:942-944 (1978).
___________ Mesoamerican historical linguistics and distant genetic relationship, ibid 83:905-911 (1981)
TABLE
The mean z-scores, calculated as described in the text, between each of 33 fossil and 5 recent human populations. The amounts-of-change adjustments present are: Norse, +0.19; Zulu, 0; Tolai, -0.01; Anyang, -0.04; Santa Cruz, - 0.13. The smallest distance or distances within 0.05 units of one another are highlighted. Afalou 29, as noted in the text, is effectively equidistant from all 5 populations.
MEAN Z-SCORES
NORSE ZULU TOLAI ANYANG SANTA CRUZ Steinheim 2.31
2.32 1.95 2.26 1.66
Petralona 2.47 2.60 2.34 2.64 1.66
Kabwe 1.94 2.01 1.85 2.05 1.20
Ferrassie 1.64 1.70 1.70 1.80 1.23
Monte Circeo 1 2.00 2.15 1.93 2.28 1.23
La Chapelle 1.96 1.98 1.88 2.23 1.36
Saccopastore 1 1.90 2.15 2.23 2.32 1.47
Shanidar 1 1.37 1.36 1.54 1.69 1.41
Gibraltar 1.78 1.99 1.65 2.09 1.17
Amud 1.99 1.97 1.97 2.24 1.39
Irhoud 1 1.60 1.63 1.39 1.73 0.88
Skhul 5 1.60 1.67 1.38 1.73 1.01
Qafzeh 6 1.35 1.40 1.32 1.22 0.83
Qafzeh 9 1.06 0.76 0.86 1.15 1.10
CroMagnon 1 1.02 1.18 1.11 1.41 1.08
Mladec 1 1.01 1.01 1.27 1.28 1.41
Predmost 3 1.20 1.22 1.05 1.42 1.04
Kostenki 14 1.27 0.96 0.82 1.21 1.23
Pataud 0.91 1.07 1.16 0.96 0.79
Chancelade 1.10 1.09 1.07 0.83 1.45
Oberkassel male 1.25 1.36 1.04 1.12 0.78
Oberkassel female 1.05 1.01 0.91 1.05 1.30
Candide 1.37 1.45 1.41 1.38 1.06
Candide 1 0.98 1.06 1.09 1.05 1.16
Candide 5 1.03 1.17 1.07 1.12 1.25
Afalou 9 1.23 1.45 1.30 0.76 0.90
Afalou 10 0.83 1.07 1.29 0.99 0.84
Afalou 29 0.96 0.99 1.03 1.00 1.02
Afalou 32 1.15 1.11 1.03 0.99 0.84
Taforalt 11 1.19 1.21 0.70 1.01 1.29
Taforalt 17 1.18 1.07 0.85 1.06 1.18
Cohuna 1.98 1.80 1.41 1.88 1.52
Upper Cave 101 1.17 1.23 0.97 1.41 0.89