The Neandertal-Human hybrid question

[juantoo3]

Kindest Regards!

In response to the growing interest in the question of Neandertal / Cro-Magnon hybrids, I have put together a few references that look at several aspects of the unusual find in Portugal of the child of Lapedo.

The first argument for our separation from Neandertals concerning morphology can be answered in two ways. First there are modern human skulls from Europe, especially from Eastern Europe, which are mixtures of traits. Mladec 5 is ostensibly a modern human, descended from the African invaders, yet he has significant neanderthaloid traits. Neanderthals were known for having an occipital bun, a different shape to the back of the cranium. Mladec 5 had such a bun (Trinkaus and LeMay 1982). Mladec 4,5 and 6 all were very robust massive supraorbital bones, and low vaults. None of these are modern traits. Smith states:

"The supraorbital superstructures are basically modern (i.e., somewhat divided into superciliary arches and superorbital trigones) but, especially in Mladec 5 closely approach the condition of a Neandertal supraorbital torus, particularly that of late Neandertal tori in South-Central Europe. Wolpoff notes that the cranial contour of Mladec 5 is similar to that of La Chapelle-aux-Saints except for a slightly higher forehead and less projecting occiput." (Smith 1982, p. 678

"According to Trinkaus, the Neanderthal condition is highly variable and 'more than half of the European "classic" neanderthals have their mental foramen mesial to M1,' which is typically the 'modern' position. Beyond this, Wolpoff has itemized a series of facial, cranial, and postcranial characters which link--not separate--European Neanderthals from the People who follow them. Thus, considerable evidence points to the persistence of these 'neanderthal autapomorphies and common traits' into the Upper Paleolithic populations which succeeded the Neanderthals in Europe. "At the same time, these identical features are generally absent in the human fossils from Africa (Omo, Border Cave, and Klasies River Mouth) and the Near East (Skhul and Qafzeh) who reputedly represent the source populations for the early Upper Paleolithic people of Europe.

"While rates of dental evolutionary change by themselves do not prove that Neanderthals are ancestral to early Upper Paleolithic Europeans, these results do indicate that European Neanderthals cannot be eliminated as possible ancestors based on speculations which require grossly elevated evolutionary rates. Moreover, the period following the Neanderthals in Europe is not characterized by absolute or relative stasis but by marked change within the Upper Paleolithic and from the Upper Paleolithic to the Neolithic. These observations should put to rest both the contention that differences between the European Neanderthals and the early Upper Paleolithic require an exorbitant rate of change and the unsupported claim that tooth size shows little absolute or relative change after the appearance of the Upper Paleolithic. Those who still maintain that European Neanderthals are unrelated to subsequent European Homo sapiens must look to other data; these data do not include the presence of so-called Neanderthal autapomorphic traits or exorbitant rates of change."(Frayer, 1997) p. 233

While I don't know how much Neanderthal ancestry is in the modern human race and am uncertain how it got there, interbreding or evolution, the above data seems to indicate that the apologetical position which tries to separate the archaic hominids from anatomically modern men fail for several reasons. Christian theology ignores this data at its peril.

http://home.entouch.net/dmd/neanev.htm

[juantoo3]

Contrary to the anatomically modern peoples, Neanderthals were short and squat with extremely hyper-arctic body forms, even more arctic than the Lapps. This is widely believed to have been due to the millennia of living in cold, glaciated Europe. Neanderthals were also hyper robust . This means that their bones were exceptionally thick compared with anatomically modern peoples. I want to use Stringer's words to illustrate what I think is a bit of a double standard in anthropology. Stringer is withholding his judgment on the nature of the Lagar Velho child, but as a strong proponent of the Out of Africa position (albeit allowing some interbreeding) a hybrid can’t be good news for his position. However, using Stringer’s own data we will show that there is a reasonable likelihood that this child is a hybrid. Chris Stringer and Clive Gamble (1993, p. 93) wrote:

"In their relatively heavy bodies the Neanderthals seem to conform to Bergmann's rule, and in the shorter ends of their limbs to Allen's rule. That the Neanderthal physique was partly determined by climate is further supported by the slight differences in limb proportions between the Neanderthals who lived in glaciated Europe and those who lived in the less extreme climates of the Middle East."

Bergman's rule is that body weights of an animals will tend to be greater in colder climates. And Allen's rule is that their limb proportions will be shorter. These rules have a wide application across many species. Thus Stringer accepts the climate-induced selection pressure that created the Neanderthal physique. How do we measure body form?

Here is how these rules apply to the Lagar Velho child. When we examine various populations, fossil and modern, we find a range of values for the brachial, crural and robusticity indices. Unfortunately the Lagar Velho child's radius is incomplete so the brachial index can't be studied. Here is the data presented by Stringer and Gamble (once again I want to use Stringer's data so that an Out of Africa proponent’s data is in play). This data is taken from a chart on page 92 of Stringer and Gamble (Stringer and Gamble, 1993, p. 92).

crural index = Tibia/Femur length
modern peoples 79% in Lapps
86% in Black African groups
Group crural Mean annual temp C
index

average Neanderthal 79% ?

Modern peoples
Lapps 79% .25
modern Inuit 81.5% 4
Belgium 82.5% 10
S.African white 83.2% 8.5
Yugoslav 83.75% 8.4
American white 82.6% 9.8
Kalahari Bushman 83.4% 18
New MexicoIndian 84.6% 14
S.African black 86.4% 17
Arizona Indian 85.5% 18
Melanesian 84.8% 23
Pygmy 85.1% 24.2
Egyptian 84.9% 26.1
American Black 85.25% 26

One sees at once that the subtropical peoples have a higher crural index than those living in cold climates. This amazingly even applies to the pygmies. Shortness is not at issue here. Body form is.

Lagar Velho has a crural index of .782 which as can be seen is lower than all anatomically modern peoples including the Lapps. This value, as we shall see is lower than ALL values for ALL anatomically modern, African invaders.

What of the Lapps. I am going to claim that is is perilously close to circular reasoning to use the Lapps as an analogue to compare with the Neanderthals for one reason. Lapps occupy a region very close to the former Neanderthal territories. If there has been any hybridization, the low crural index of the Lapps might be indicative of that hybridization. In other words one cannot tell if their squatness was due to genetic heritage or the accumulation of the trait since the invasion of anatomically modern peoples. The only way one can use the Lapps as evidence that a low crural index means that the Lagar Velho child is nothing special is if they ASSUME THAT THERE WAS NO HYBRIDIZATION. That is assuming the conclusion! I would say that the Inuit make a better case for the acquisition of a low crural index by the African invaders. This is because the Inuit were nowhere near the Neanderthal homelands.

About 100,000 years ago, anatomically near modern peoples appeared in the Middle East at Skhul and Qafzeh Caves. So, we should look to these peoples for the archetypes of the modern humans who invaded Europe. But we do need to be careful in our analysis. Neanderthals lived in the Middle East along with anatomically modern men and if there could be hybridization in Spain, then it could have happened in the Mid East also. What do we find? We find that, with one exception, all the Skhul/Qafzeh skeletons clearly have subtropical body forms. Frayer shows the crural index on the Skhul/Qafzeh peoples. There are three individuals with enough skeletal matter to make this measurement on. One has a crural index of 89, one has an index of 86 and Skhul V has an 80.(Frayer, p. 33, 68, Fig 9)

Obviously, one can argue that Skhul V shows that the range of the crural index is so great as to make meaningless the measure on the Lagar Velho child. But in anthropology things are rarely that simple. Two things argue against this position. The Lagar Velho child has a crural index of .782 which is much smaller than the .80 of Skhul V. But then Skhul V has been suggested to be an hybrid also. Johanson and Blake (1997, p. 242) write of Skhul V:

Skhul V
"Others have subsequently interpreted Skhul V's anatomy as showing signs of hybridization between modern and Neandertal populations. Hybridization is difficult to demonstrate in fossils, and even if it did happen rarely, it would not mean that Neandertals and modern humans were a single species. The Tabun individuals clearly differed from those at Skhul, who were undoubtedly on the cusp of becoming modern humans."

It is interesting that the same trait is used to support hybridization with Skhul V as with the Lagar Velho child.

I would suggest Johanson and Edgar are wrong in that if interbreeding did occur biologically we are the same species. They would be the same species according to the biological definition of species.

What of the theological viewpoint? Many Christian apologists latch on to the concept that Neandertal was a separate species. What they don’t understand is the definition of such a species. There is the biological definition of species in which interbreeding and the production of fertile offspring defines who is and who isn’t a species. The alternative definition is that two populations are separate species IF in the normal course of affairs they don’t interbreed (for whatever reason). They might be capable of interbreeding but they don’t do it. This is the definition which Johanson and Edgar, as well as Tattersall are using.
The difficulty this definition presents for the theologian is that one could claim that until the modern era, Black Africans were a separate species. Indeed, many Christians of the last century (and a few in this one) held exactly that view. That view was used to justify racism. For Christian apologetics, it seems to me that the best definition is that which reduces the opportunity for racism. If modern humans could produce offspring (fertile or not) with Neanderthals, we can not exclude Neandertals from humanity. (*emphasis mine, eugenics anyone?)

Obviously there is one skeleton that doesn't fit what they say {selective use of data? Note here that I am using data like the Lapps and Skhul V which don't initially fit within the position I am advocating and that is what a person should do]. Now, if Stringer and Gamble are correct in ignoring Skhul V and dismissing him as a possible hybrid, then the measurement of a Neanderthal-like crural index becomes even more problematic for their position. They have to explain how, among ALL upper Paleolithic anatomically modern humans, this one child, this single individual achieved a Neanderthal-like body form during the more moderate climatical times of 24,000 years ago when no other anatomically modern person in Europe was able to achieve this body form! How do I know this? Frayer (again in Figure 9 p. 68) shows the crural indices for European hominids from 90,000 years ago to the present. The Skhul/Qafzeh peoples have the ranges I mentioned above. Neanderthals from 70,000 years ago have crural indices ranging from 76-81. Since the earliest anatomically modern fossil dates from 34,000 years ago and is fragmentary, the earliest anatomically modern crural index is from about 28,000 years ago and has a value of 88. At 25,000 years ago there are 7 specimens with a crural index range of 84-88. At 24,000 years the range is 82-83. At 20,000 years ago the range is from 79-87 Between 15,000 and 10,000 the range is from 81 to 90.5. I might point out that the 79 at 20,000 years ago is only one individual. The next lowest above him at that time is 82. As Frayer notes, the average crural index of anatomically modern humans has remained around 84 throughout the past 30 millennia. Only as one gets into the height of the last glacial age and on do we find anatomically modern peoples with low crural indices. The finding of an individual like Lagar Velho is clearly out of step with the rest of the data for European men.

One of the weakest reasons for placing Neanderthal in a separate species that I have ever seen comes from Tattersall and Schwartz' commentary. They state(1999, p. 7117):

"In contrast, if we see them [Neanderthals] as mere subspecific variants of ourselves, we are almost obliged to dismiss the Neanderthals as little more than an evolutionary epiphenomenon, a minor and ephemeral appendage to the history of Homo sapiens."

This almost sounds like a religious reason, a doctrinal reason rather than a scientific reason for making Neanderthals a separate species. Who cares how we view them? What is important is the correctness of how we view them.

They do admit that if this is a hybrid, then we are the same species, no more than a racial variant. (Tattersall and Schwartz, 1999, p. 7117)

Tattersall and Schwartz critisize the hypothesis because there is no dental or cranial evidence of Neanderthal morphology. But they are criticizing what Duarte et al freely state in their paper. Duarte say that the child is a mosaic, not a morphing of form which is what Tattersall and Schwartz seem to expect. And as a mosaic, some parts will be Neanderthal like and some modern. (*emphasis mine)

Tattersall and Schwartz say that this child can’t be due to long interbreeding, as Duarte et al claim because the child is more like a first generation hybrid, ignores the possibility that this very well might be an F1 hybrid. The latest Neanderthal dates somewhere around 28,000 years ago, merely 4,000 years before the Lagar Velho child. Are we really to believe that the 28,000 year old burial was the burial of the ABSOLUTELY LAST NEANDERTHAL ON EARTH? Of course not. Neanderthals lived for some time after that but we don't know how long. So, one can't entirely rule out that Neanderthals lived until the 24,000 mark. After all, human remains are rather scarce even during that time. Even Stringer mentions that possibility. (Stringer, 1999)

Tattersall and Schwartz spend a lot of time discussing the jaw, but very little time (one paragraph) discussing the postcranial remains which is where the major data supporting the hybridization hypothesis lies. Thus, they spend most of their time on the parts that support their view and little on the data that goes against their view. Yet their opinion is claimed to have done away with the hypothesis. This is good sleight of hand (don't look at the man behind the curtain), but very poor scientific procedure. It is precisely the data supporting the Neanderthal hybridization hypothesis upon which they should have spent most of the time.

They also left totally unchallenged the neck-shaft angle data in Duarte et al which shows that the Lagar Velho femur is more similar to Neanderthal.

They claim. "And the tibia, like the femur, is hard to evaluate in the absence of the epiphyses; it does not appear significantly different from what one might expect to find in a robust modern human of this age." Tattersall and Schwartz. (Tattersall and Schwartz, 1999, p. 7119)

And they say, " The probability must thus remain that this is simply a chunky Gravettian child, a descendant of the modern invaders who had evicted the Neanderthals from Iberia several millennia earlier." (Tattersall and Schwartz, 1999, p. 7119)

This simply does not conform to the facts. Anatomically modern humans are demonstrably less robust than the archaic variants of Homo sapiens. The data I showed above and the data presented in Duarte et al clearly shows that the Lagar Velho child is much more robust than African invaders. The Lagar Velho child's legs are much more Neanderthal-like than ANY pre 22,000 year old African Invader. If this is no hybrid, where are all the other anatomically modern fossils with similar crural indices and robusticities from which this child could have received his genes? Or did the child self-create his own genetic heritage?

http://home.entouch.net/dmd/hybrid.htm

[juantoo3]

The skeletal anatomy of LV1 and its significance: Preliminary descriptions of the child’s anatomy have already been published. His age at death is estimated to lie between 3.5 and 5.0 years and there are no indications of pathological conditions that might have affected normal skeletal development. During the excavation it was assumed that the skeleton represented that of a Gravettian early modern human child belonging to a population no different from those well documented by the numerous contemporary burials from Moravia, Italy and Russia. This view was initially based on the clear presence of a very prominent chin.

Further analysis showed that the skeleton also possessed a suite of other traits that aligned it with the known sample of early modern humans from Europe and the Near East. For instance, Neanderthals exhibit relatively larger anterior mandibular teeth than early modern humans. In this regard, the Lagar Velho child falls in the middle of the early modern human distribution. In addition, Neanderthals and early modern humans contrast in the relative proportions of their thumb phalanges, a pattern that is established early in development among recent humans and at least by late juvenile years in Neanderthals. Hence, the comparison is relevant, and in this regard too the Lagar Velho child closely approaches the proportions seen among early modern humans and is distinct from the Neanderthal pattern.

Other features of the child’s anatomy, however, suggest clear Neanderthal affinities. Of paramount importance in this regard are the relatively short lower limb segments, reflected in the proportions of its tibial length to femoral length. This ecogeographical proportion, indicating a hyperarctic pattern among the Neanderthals and a tropical one for the European early modern humans (as well as the Levantine early modern human Qafzeh-Skhul sample), completely separates the Neanderthals from these early modern human groups. The Neanderthals have proportionately shorter tibiae relative to their femora. These proportions appear early in development, are well documented for Neanderthal children, and remain stable for a number of millennia in Late Pleistocene and Holocene human populations.

These conclusions are the result of extensive research carried out among both modern and fossil populations and are widely accepted among students of human evolution. Commentators of the anatomical features of the two-year old Dederiyeh child from Syria, for instance, have remarked that the presence of the distinctive Neanderthal body shape in such a young child emphasized the importance of a genetic component in the development of this feature. Therefore, there does not seem to be any reason to reject using the tibial to femoral length proportions of LV1 to indicate its morphological affinities. And the comparison with a recent human cool temperate sample, with the La Ferrassie 6 Neanderthal, and with the Levantine early modern Skhul 1 specimen, shows that the Lapedo child clearly has tibiofemoral proportions in line with those of the Neanderthals. This is reinforced by the closeness to Neanderthals shown when robusticity of the leg bones is analyzed using plots of the femoral and tibial midshaft circumference to length (figs.7,8).

A second feature indicating Neanderthal affinities is the retreat of the mandibular symphysis, despite the presence of a prominent mentum osseum, or bony chin. Suggestive of Neanderthal affinities is also the fact that the left humerus exhibits a prominent ridge along the M. pectoralis major insertion leading up to the anterior greater tubercle. The proximal humeral diaphyseal morphology of the child implies hypertrophy of the chest and upper arm musculature, a pattern seen in Neanderthals but usually little developed among early modern humans.

It is this morphological mosaic which forms the basis for the interpretation that LV1 is a modern human child with genetically-inherited Neanderthal traits. Given its geochronological and geographical position, this indicates that the population to which it belonged was the evolutionary product of a process of admixture between Neanderthals and early modern humans occurring several millennia before, at the time the latter first dispersed into Iberia, 28,000 to 30,000 years ago. Put another way, this unique combination of derived modern human traits with genetically-inherited Neanderthal traits must be considered phylogenetically significant and suggests that the last Neanderthal groups living in Iberia ca. 28,000 years ago contributed to the gene pool of subsequent early Upper Paleolithic populations of the Peninsula.

Neanderthal-modern admixture and interaction in the empirical record: However, as is the case elsewhere in Europe, no demonstrably Neanderthal-modern mixed cultures exist in the Iberian Peninsula. The earliest Upper Paleolithic industries of Portugal and southern Spain show no Mousterian influence, and no Upper Paleolithic influence is noticeable in the latest Mousterian industries from these regions. Although it could be argued that the lack of evidence for admixture in the cultural realm contradicts the phylogenetic interpretation of the Lagar Velho child’s anatomy, such an objection would not be pertinent. (*emphasis mine)

The last Neanderthals: anatomically archaic, behaviorally modern. What the above discussion makes clear is that, regardless of the differences manifested in the archaeologically-documented features of their cultures, the contact and interaction between Neanderthals and moderns as individuals and groups was one of people versus people, not “people” (the moderns) versus “animals” (the Neanderthals). The hypothesis that moderns held some kind of biologically-based intellectual advantage that would have led to a sweeping replacement of Neanderthals, the latter having become extinct without descent, is clearly contradicted by the geographical features of the process outlined above:

…those features of the Châtelperronian which were attributed to acculturation (if not simple imitation) from contact with their modern neighbors are in fact independent cultural developments that arose among some central and western European Neanderthal groups well before moderns started to penetrate the continent. The production of the numerous fine bone and ivory tools and of the abundant body ornaments recovered in the Châtelperronian levels of the Grotte du Renne, in Burgundy, France (but also known at other French, Austrian, German and Crimean sites), shows that the cultural behavior and the intellectual capabilities of the anatomically archaic Neanderthals were as “modern” as those of the anatomically modern “moderns” (fig. 11). Moreover, they were being produced more than 38,000 years ago, while no secure dating evidence exists for the Aurignacian (taken as a proxy for modern humans) before ca. 36,500 years ago anywhere in Europe (fig. 12).

Conclusion: Recent DNA research has shown that Neanderthals are significantly different from recent humans. From this, it has been inferred by many that they must also have been significantly different (for some, even at the species level) from the contemporary early modern humans that would have replaced them without admixture. This is an anti-evolutionist view, since it assumes that nothing changed in the genetic make-up of anatomically modern humans ever since they first arose from the original mitochondrial Eve 150,000 years ago. Since it is quite clear that evolution did not stop with the birth of Eve’s children, and since it has been an established paleontological fact for about 100 years that the people who currently live on planet Earth are not Neanderthals, these DNA results contribute little to our understanding of what happened in that critical period between 50,000 and 25,000 years ago during which the Neanderthal phenotype disappeared. More Neanderthal samples need to be analyzed, while reliable criteria to ascertain whether the DNA of a Neanderthal that looks like a modern is contaminated or genuine need to be established. Samples of the DNA of early modern humans (so far none have been obtained) have to be used as the basis for these comparisons.

Meanwhile, the archaeological and physical anthropological features of the empirical record suggest that, in order to be productive, further work should proceed on the basis of the recognition of the following realities:

1) That Neanderthals fared well and for many millennia in certain parts of Eurasia before being replaced by modern groups, i.e, that, on a continental scale, there was a long-term contemporaneity between the two;

2) That there is no evidence of a long-lived contemporaneity on a local/regional scale between the two groups, implying

a) either rapid replacement with minimal cultural interaction and minimal biological admixture, perhaps as a result of a behavior of mutual avoidance, which is conceivable in the core continental areas of Eurasia;

b) or intensive interaction and extensive admixture, which must have been the rule in the geographical culs-de-sac that were Neanderthals’ last refugia once the stable frontiers that separated them from moderns eventually collapsed;

3) That anatomical traits are a much better indicator of potential admixture than stone tool technology.

http://www.athenapub.com/8zilhao1.htm

The Evolution Conflict

There is much more to the story than simply dentition. Whether or not a hybrid admixture of Neandertal and modern Human genes could survive to be viable and produce further offspring is a question still open to discussion. There is not enough conclusive evidence one way or the other. What Lapedo and Skhul V show is that, viable or not, Neandertal and Cro-Magnon did interbreed. I am of the opinion that there was some cultural interaction between the two groups, that could lead to interbreeding. Whether this was through commerce (trade or barter), coexistence in the same proximity and mutual cooperation for survival, or perhaps even through warlike activities (stolen “wives”) at this point can only be conjecture.

[Bandit]

sorry i dont have much to add here Juan. i am kind of watching this one develop so thanks for the updates & possibilities.

[I, Brian]

There's a lot of debate on the issue - I think we may find a few surprises yet, after a few more years of research.

[juantoo3]

Kindest Regards, Brian and Bandit!

Thanks.

I agree Brian, and that is pretty much the point I was trying to make. There is far too much going on in this field to conclusively and boldly state that there was "no interbreeding" between Neandertal and Cro-Magnon. It is evident there was some hanky-panky, but how much, to what extent and whether or not the offspring were viable, are all still very open to debate among researchers in the field.

I just thought it a bit bold to assert that genetically there was no possibility that Lapedo was a hybrid, particularly when that assertion was based solely on teeth, half of which were missing, while totally ignoring the remainder of the physiology.

[juantoo3]

Kindest Regards, Tao Equus!

I did not properly thank you for the initial link you provided. I do think the find of a Neandertal child in the Caucasus Mountains can only add to the understanding in the field. Perhaps here, in a thread devoted to the subject, we can expand a bit better without highjacking the other thread.

The expansion of premodern humans into western and eastern Europe 40,000 years before the present led to the eventual replacement of the Neanderthals by modern humans 28,000 years ago. Here we report the second mitochondrial DNA (mtDNA) analysis of a Neanderthal, and the first such analysis on clearly dated Neanderthal remains. The specimen is from one of the eastern-most Neanderthal populations, recovered from Mezmaiskaya Cave in the northern Caucasus. Radiocarbon dating estimated the specimen to be 29,000 years old and therefore from one of the latest living Neanderthals. The sequence shows 3.48% divergence from the Feldhofer Neanderthal. Phylogenetic analysis places the two Neanderthals from the Caucasus and western Germany together in a clade that is distinct from modern humans, suggesting that their mtDNA types have not contributed to the modern human mtDNA pool. Comparison with modern populations provides no evidence for the multiregional hypothesis of modern human evolution.

Writing in Thursday’s issue of the journal Nature, William Goodwin of the University of Glasgow in Scotland, along with collaborators from Russia and Sweden, report that the baby’s DNA is much more similar to another Neanderthal DNA sequence reported in 1997 than to that of modern humans.

An earlier Neanderthal DNA sequence was determined from bones found in Feldhofer Cave in Germany.

The researchers isolated segments of DNA from the baby’s mitochondria — small, energy-producing bodies within a cell that contain their own genetic code separate the main DNA strand in the nucleus of the cell. Mitochondrial DNA is easier to study, because each cell contains about 1,000 mitochondria, meaning there are about 1,000 times more DNA strands to extract. Unlike cell DNA, mitochondrial DNA is inherited only from the mother

The baby’s mitochondrial DNA differed from that of the other Neanderthal in 3.5 percent of the locations tested, while the divergence from humans was 7 percent. Scientists consider that to be a substantial gap. "It all points away from the Neanderthal," Goodwin says.
Based on the number of differences, and the expected rate of change, Neanderthals and humans last shared a common ancestor about 500,000 years ago, the researchers say.
The Neanderthal DNA was also no more similar to the DNA of Europeans than people elsewhere, which might have been expected if Neanderthals had mated in large numbers with their human neighbors in Europe.

http://cogweb.ucla.edu/Abstracts/Goodwin_00.html

I have pulled some relevant quotes from the link you initially provided that I would like to touch on as an interested observer. (read: amateur, armchair anthropologist)

The first thing I noted is the numbers pertaining to when “Africans” moved into Europe. Here it is stated, rather succinctly, that this migration event took place 40 thousand years ago. Yet, there are known finds of “Africans” on the Eurasian continent that are dated as far back as one hundred thousand years and more. Arbitrary figures…we don’t have any specificity, it is guesswork at best. Even with carbon dating. Skhul V is dated as I recall somewhere on the order of 100 thousand years ago, and is considered by some to show possible hybridization. Granted, this was not in Europe, it was in the Middle East, but the influx of Africans onto the Eurasian continent must have already begun by this time.

This reference claims a second mtDNA sampling on Neandertals, but as pointed out by Glen Morton in one of the references I posted above, mtDNA sampling has not been done yet on pre-historic Africans (Cro-Magnon). At least, not that has been brought to my attention. Comparing this DNA sample with modern humans is going to create some difficulties in my mind.

For instance: “The baby’s mitochondrial DNA differed from that of the other Neanderthal in 3.5 percent of the locations tested, while the divergence from humans was 7 percent. Scientists consider that to be a substantial gap. "It all points away from the Neanderthal," Goodwin says.”

Now, I’m not quite certain how to understand this. Looking around, I see figures of from 3-5% divergence between humans and bonobos, from everywhere between the Nature channel and specific researchers involved in the human genome mapping project. So, if I am to take what this reference says at face value, I am to believe we are more closely related to bonobos than we are to Neandertal? This, despite the generally accepted conclusion that the common ancestor of Neandertals and Cro-Magnon is around 150-200 thousand years ago (this reference claims 500 thousand years), yet the common ancestor between bonobos and humans is much, much greater than that. Somewhere on the order of 1-2 million years. Now, I am in agreement that 3% is a “substantial gap.” But not substantial enough, apparently, by some of the findings of Neandertal / Cro-Magnon hybrids. Either this hints that bonobos and humans can interbreed, or somebody’s figures are not quite correct.

I think it is only proper to note that late Neandertals were every bit as “cultured” as Cro-Magnon of the time. As I recall, Neandertal had larger brains, developed tools before Cro-Magnon, and otherwise exhibited trade and industry, communication and culture, including religion and “common welfare,” very comparable to their Cro-Magnon neighbors. Whether by trade or “borrowing” is unclear.

I admit to not fully understanding the implications of mtDNA analysis, but since mtDNA comes only from the mother, it seems to me that only half of the child’s actual DNA is being measured…are these researchers possibly comparing apples to half-apples? Note too, that this comparison is only with one other Neandertal. It does seem pretty apparent that it is a comparison of an infant to an adult, of which there is, I would think, a pretty good degree of latitude in interpretation.

As for “The Neanderthal DNA was also no more similar to the DNA of Europeans than people elsewhere, which might have been expected if Neanderthals had mated in large numbers with their human neighbors in Europe,” I see a couple of things. First, I agree with Trinkhaus, in that it shows that hybrids were not a common happening. Or, the Neandertal DNA has been so dispersed among modern humans as to make differentiation impossible. Either way, it does not refute the possibility of hybridization in specific instances.

I will go one step further. Concluding that such hybrids were “mules,” that is sterile and infertile, is again purely conjecture without evidence. That evidence is not likely forthcoming because there are no living Neandertals to “test” the hypothesis. But I can give some relevant examples, the most notable being Prezlewski’s (sp?) wild horse being able to freely mate with standard horses, with very viable offspring. Despite the acknowledged fact the wild horse has two more genes than the standard horse. So even in the world of Equines, “mules” are not a given. Even among hybrids that typically produce sterile offspring, it is known that occasionally there is a viable hybrid produced. This does not suggest any great impact on evolutionary development, but it is a known curiosity. If this were the case, a viable hybrid that is typically sterile, then the impact on a given population would be minimal and very localized. If, on the other hand, Neandertal were sufficiently similar to produce viable offspring with Cro-Magnon, it could very easily be that the cause of their disappearance was by being absorbed so totally as to not leave much of a trace of their existence. The two “evolutionary branches” could have grown back together.

There are other considerations as well, but this is sufficient I think for now.

[Tao_Equus]

Hi Jauntoo and you'r right this does need its own thread.

First off neither did I intend to be in any sense argumentative. The competition between the the divergents and the out of africa camps of anthropologists does seem to cloud the debate at times. Rightly or wrongly this is why my own personal most likely scenario is based entirely on the work of geneticists.
Contrary to what you have written there have infact been 3 extractions of mtDNA from Neanderthals, from the Caucasas, Germany and Croatia. The genetic difference between the 3 samples are comparable to that of modern europeans, africans and native australians. The 2 Italian scientists that did a comparative study of these samples, and also compared them with modern man and the great apes, concluded that like modern man Neanderthals evolved from a rather small population only much further back in time than us. All 3 samples shared significant genetic features that are not found in any modern humans, but should be if we were interbreeding as little as 30,0000 years ago, which led them to conclude that our cro-magnun ancestors did not successfully interbreed. This is not to say that it was not possible or that it did not happen in some instances, but that the genetic heritage of neanderthals is not present in modern man. NOTE: I have been trawling the Proceedings from the National Academy of Sciences site trying to find this paper, where I know it was published, but as I cant recall the name of the two Italians its not easy. I will endeavour to do so however.

mtDNA studies are pivotal to the 'out of Africa' hypothisis of modern man and show that we all share a common small group of ancestors, possibly numbering as few as 30 individuals. This group is believed to have come from somewhere close to central Africa and lived around 150,000yrs ago. Earlier common ancestors are found throughout the old world and in Australia which shows that Homo-erectus spread far and wide, as would be expected of such an adaptable species. Divergent theories however cannot dismiss the mtDNA evidence. And it is not half an apple, we all carry mtDNA but it is only passed, and almost intact, from the mother. Nuclear DNA is subject to 50% change with each reproductive cycle.

The differences you allude to in comparing bonobo and neanderthal are because, I think, one is measuring nuclear DNA and the other mtDNA.

I do have more to add but unfortunately I have to go out. Hope this makes it clear why I tend to believe that unfortunately we were less than freindly to our Neanderthal cousins.

Regards

TE

[Tao_Equus]

Hi

Still searching for that paper without success. Have however found the following link that gives a plethora of links to related articles; http://www.geocities.com/CapeCanaver...917/mtdna.html


Regards

TE

[juantoo3]

Kindest Regards, Tao Equus!

Apologies for the late response. My schedule, ..., (*broken record*)...

Thank you for the resource! The link doesn't work, but I took what my cursor revealed and was able to paste into the address bar and gain access at work. I printed out a number of papers, but I was a bit disappointed that some of the ones I was most interested in cost $30 bucks apiece. I appreciate artistic control over intellectual property, but this is relating to a scientific and educational subject.

I am still going through the literature. I did find, and printed, what I believe to be the paper by Duarte, et al, that Morton refers to in the previous posts. When I get a chance to finish going through the material I have I will post some of the relevent stuff I have read.

I did a read of a short paper on the development of thought in prehistoric humans. Or better stated, a critque of another paper on thought. A lot of it referenced things I am not familiar with, but there were a few interesting tid bits to nibble on.

The research isn't going away soon. If this thread takes a little while to develop, that's alright by me. So please don't be too upset if I do not respond quickly. Thanks again.

[juantoo3]

I hope you will not mind, I did see a couple of things I wanted to address.

Originally Posted by Tao_Equus

Contrary to what you have written there have infact been 3 extractions of mtDNA from Neanderthals, from the Caucasas, Germany and Croatia.

I want to say I was quoting another. I don't know for fact how many have been sampled, you are the first to bring this to my attention. I did find some material that deals with this, but I still have reservations concerning comparison *solely* with mtDNA of modern humans, not Cro-Magnon Africans of similar age as the Neandertal samples. If the hypothesis of constant rate of change in the genome bears any weight, it hardly seems accurate to compare against samples of recent age to make comparison for the sake of possible ability to interbreed between Neandertal and Cro-Magnon in antiquity.

The genetic difference between the 3 samples are comparable to that of modern europeans, africans and native australians.

OK, I do not know precisely what that difference might be, but the same source from where I pulled my quotes of Francis Collins and Craig Ventor includes a comment that the difference between the two most divergent humans on the planet is half of one percent. (.005) Out of 30 thousand genes. So I am guessing that the differences between "modern europeans, africans and native australians" is much, much less. Certainly nowhere near 6% plus for Neandertals. Of course, I did not take the samples or perform the dating or analyze the data.

which led them to conclude that our cro-magnun ancestors did not successfully interbreed. This is not to say that it was not possible or that it did not happen in some instances, but that the genetic heritage of neanderthals is not present in modern man.

Of course, this is also certainly a possibility. You suggested elsewhere that you believed Neandertal met a rather violent end at the hands of Cro-Magnon. I know that is the long standing belief in the field, especially prior to Lapedo. And Lapedo does not do away with that possibility. Personally, I do think that most of the Neandertal population probably did meet an unfortunate end at the hands of Cro-Magnon in some form or type of warfare. Which is why my comment about stolen wives, much as Native Americans sometimes did.

There have been one or two findings that initially suggested cohabitation of Nean. and C-M, only to be reinterpreted later as not being the case. There are caves with findings from both cultures separated by layers of sediment (some very thin, suggesting only a few hundred years separation). Both buried their dead with respect. Both have shown signs of caring for their wounded. And there are some few examples of the artwork of one being found in possession of the other. So there is some hint as well of cultural interaction in a more friendly manner. (Although war, philosophically speaking, is still a manner of cultural interaction, albeit not a pleasant one)

I have been trawling the Proceedings from the National Academy of Sciences site trying to find this paper, where I know it was published, but as I cant recall the name of the two Italians its not easy. I will endeavour to do so however.

I look forward to seeing this paper presented.

Homo-erectus spread far and wide, as would be expected of such an adaptable species.

This reminds me of something else I read, although it escapes me exactly where and in what context. One of the papers I read suggested that (I believe it was) h. erectus also lived contemporaneously with Neandertal and Cro-Magnon for a time. Three species of humans at the same time walking the planet...interesting (to me anyway).

And it is not half an apple, we all carry mtDNA but it is only passed, and almost intact, from the mother. Nuclear DNA is subject to 50% change with each reproductive cycle.

Again, I am not familiar enough to refute or agree. I do seem to recall that mtDNA is passed from a mother to all of her children, but through those children who are daughters that mtDNA again passes, relatively unchanged, to yet another generation. Through a successive string of daughters, as I understand the idea, mtDNA would remain virtually unchanged for generations, even thousands of years. It is on this basis that "mitochondrial eve" and "common ancestor" hypotheses come from.

Now, I understand mtDNA is far easier to acquire in sufficient quantities to examine than nuclear DNA, but I still can't shake the feeling it is only half of the story.

The differences you allude to in comparing bonobo and neanderthal are because, I think, one is measuring nuclear DNA and the other mtDNA.

Perhaps. I think it also displays the old adage, "numbers don't lie, but you can lie with numbers." So even though I am certain there are advocates from both opposing camps that can throw numbers around quite well, in the end it is all only educated guesses. And prevailing politics. And grant money.

I am very much enjoying this discussion, even if I am not as able to participate as I would like to. Thanks again!

[Tao_Equus]

Hi Juantoo,
thx for your reply. I have uncovered some more details on this subject which I shall post once I have time to coherantly present them. One of which is the fact that some 10 neanderthals have now been mtDNA sequenced!!
I have now found the link to the Italian study, sorry it took me so long but I am useless and just learning, without aid, how to use a computer. Anyway, here it is:
http://www.pnas.org/cgi/gca?allch=&SEARCHID=1134490455664_6429&FULLTEXT=It alian+scientist+mtDNA+neanderthal&JOURNALCODE=&FIR STINDEX=0&hits=10&RESULTFORMAT=&gca=pnas%3B100%2F1 1%2F6593&allchb=

Regards

TE

[juantoo3]

Sorry Tao, this link didn't work for me at all. Those PNAS guys sure are paranoid about someone reading their papers. I tried monkeying with the link you gave to see what I could get to come up and I kept getting the same error message, so something is not translating well. This is the same bunch I was talking about wanting $30 bucks per paper. (non-subscriber price, of course)

BTW, are you sure you're "just a cook?" If you are only now getting around to using a computer, yet have the collection of knowledge you obviously do, hmmm....

In any event, glad to have you around!

[Tao_Equus]

Hi Juantoo,

Originally Posted by juantoo3

Sorry Tao, this link didn't work for me at all. Those PNAS guys sure are paranoid about someone reading their papers. I tried monkeying with the link you gave to see what I could get to come up and I kept getting the same error message, so something is not translating well. This is the same bunch I was talking about wanting $30 bucks per paper. (non-subscriber price, of course)

Hmmmm, sorry about that, probably my fault. I will give you the name of the paper and you can go to the PNSA site and look it up, its; Evidence for a genetic discontinuity between neandertals and 24,000-year-old anatomically modern Europeans. Published May 12th 2003 10.1073/pnas.1130343100.
I dont understand how you are being asked for $$$ to see papers here, that has never happened to me and I am able to read anything on their site free of charge. Could it be you are not clicking on the 'abstract' and instead requesting a print ready version?

BTW, are you sure you're "just a cook?" If you are only now getting around to using a computer, yet have the collection of knowledge you obviously do, hmmm....

lol, be carefull....if you flatter me like that I may start posting even more In answer yes I am just a cook. I did subscribe to New Scientist and Scientific American for many years and was an avid reader of non-fiction, until I bought this wretched machine. For about 10 years I worked with trees, first the fruiting varieties and then later forestry. During that time I did study the associated biology through open learning and short intensive courses. More recently I did a foundation year of open learning with the BBC's Open University titled 'Introduction to Science'. Basicly I'm just thirsty for knowledge of the world around us and make some effort to keep up with the latest research. As for my computer skills, well I still have not figured out how to cut and paste text into this box

With reference to an earlier post I have found out that the estimated rate of mutation in mtDNA is as low as 1 mutation in 10,000yrs. The Wikipedia site seems to have a pretty good summary of what mtDNA is and why its so useful for studying genetic changes.

Regards

TE

[juantoo3]

Thanks Tao!

I finally found and read the paper. Interesting. I can see where they have concluded that Neandertal genes have not made it into mainstrean human genes. And I see that they did compare with two Cro-Magnon from southern Italy dated almost comtemporary with the Neandertals they compared against.

Lapedo did make me begin to wonder how we should interpret the possibility of having Neandertal genes in our make-up, what implications there might be towards the various religious institutions. Now I can see that is most likely a moot point. Thanks again, I have a great deal more to go through.

I still have reservations about using mtDNA though.