That aspect is, quite simply, the frequency of sea mammal remains present in those assemblages. Now, the authors and commentators have been right in emphasizing that both Middle and Upper Paleolithic hominins display the same behavior and that is a big deal: it is one more solid uppercut to the jaw of the argument that Neanderthals and modern humans were somehow fundamentally different from a behavioral standpoint. That this is true for subsistence patterns is especially important since, as a colleague of mine likes to emphasize, it's how much calories you can extract from an environment that allows you to have more babies and keep them alive (i.e., be reproductively successful)! So, showing that people in the late Middle and early Upper Paleolithic procured resources similarly is an important observation indeed. This is the basis on which people can somewhat legitimately claim that Neanderthals could act in 'modern' ways.
In contrast, my view is that the sea mammals from Gorham's and Vanguard Caves do not support the idea that Neanderthals acted in a recognizably modern way. But here's the catch: neither did the early Upper Paleolithic, presumably modern human, foragers! In other words, yes, Neanderthals and early modern humans acted in comparable manners, but no, that behavior is not what we can really consider modern, based on what we know from historic and prehistoric hunter-gatherers.
What leads me to this conclusion is the proportion of sea mammals to other animals at those sites. I consider the mollusks uncontroversial, since there's plenty of evidence they were exploited by coastal Neanderthal and early modern humans as far back at OIS 6. So, focusing on sea mammals and fish, what do we get?
We get a really weird pattern! Let's start with the material from Vanguard Cave (Stringer et al. 2008: Table 1). We have a NISP (number of identifiable specimens - I could use MNE's instead, but the results are only marginally different, and laden with their own peculiar problems) of 9, with NISP's of 172 for terrestrial herbivores and 20 for carnivores. This means that herbivore remains are almost 20 times more abundant than those of sea animals. Perhaps even more interestingly, carnivore remains are twice as abundant as those of sea animals. The authors talk about the low rate of carnivore gnaw marks on the sea and land mammals at the site (in addition to the absence of traces of human processing on the carnivore remains), implying that carnivores and humans probably occupied the cave at different times. That being the case, it means that carnivores that were not accumulated by humans are twice as frequent as the sea mammal remains.
Before discussing what I think this means, let's turn to Gorham's Cave, where modern human behavior is presumably also documented, in Level III (Stringer et al. 2008: Table 4). In this case, for Neanderthals (Level IV), if you lump together seal and fish (NISP = 3), it means that herbivores (NISP = 49) are 16 times more frequent than sea animals. As for carnivores (NISP = 36, again assumed to be non-accumulated by humans), they are 12 times more frequent than sea critters. In Level III, the sea animal NISP is 5, while that of herbivores is 186 (37 times more frequent than sea animals!) and that of carnivores is 30 (or six times the amount of sea critters). There are also some interesting patterns of small game use at Gorham's, which I'll return to in a bit.
But first why is this pattern of relative representation of sea animals important? Because this is not how ethnographically documented foragers that depend on sea animals. In fact, foragers that have access to sea mammal tend to focus on them a lot! The data I summarized above suggest that the sea mammal:herbivore ratio of the Gibraltar assemblages is as follows:
Vanguard: 172:9 = 19.1
Ghoram's IV (Neanderthal): 49:3 = 16.3
Gorham's III (H. sapiens): 186:5 = 37.2
In contrast, for ethnographically-documented forager groups that depend to sea animals and land mammals, the same ratio ranges from 0.16 (meaning sea animals are six times more frequent than land mammals in the group's diet) to 12 (where land mammals are 12 times more frequent than sea resources) (this is based on data summarized in Kelly 1995: Table 3-1). That latter figure is probably an overestimate, however, since the one group that is associated with the ratio value of 12- the Aeta - procures extra amounts of meat to trade for carbohydrates with neighboring agriculturalists, a situtation that is clearly inappropriate for the comparison being undertaken here. Shifting to the next group down the list of most 'meat vs. fish', we get the Nunamiut, with a ratio of 8.7. This allows us to complete the table above thusly:
|Ghoram's IV (Neanderthal)||16.3|
|Gorham's III (H. sapiens)||37.2|
|Most sea mammal focused hunters||0.16|
|Least sea mammal focused hunters||8.7/12|
Whether we go with the Aeta or the Nunamiut, the picture is the same: the ratio of land to sea resources of hunter-gatherers is much lower than that documented in any of the three assemblages presented by Stringer and colleagues (2008). Notably, the ratio for those foragers that heavily depend on sea resources is smaller by orders of magnitudes than that found in any of the Gibraltar assemblages. Perhaps most importantly, the Gibraltar ratios are much, much higher than those of those hunters that target the least amount of sea mammals in their diets.
Plainly put, this means that when foragers exploit sea animals, they exploit a hell of a lot more of them than is documented in Vanguard and Gorham's Caves. One may quibble about the fact that I overlooked the Vanguard mollusks in this analysis, but since these are absent from the Gorham's Cave faunal assemblages discussed here, for the purposes of comparing early H. sapiens and Neanderthal behavior, the case stands nevertheless. In short, what we're seeing at Gibraltar bears departs significantly from the subsistence strategies of known forager groups.
Now, obviously, we have to be careful not to impose on the past observations from the present, the old "tyranny of the ethnographic record" (Wobst 1978). However, there is a reason why people focus on sea animals when they have access to them: they are often full of sweet, delicious fat. So, when they know when, where and how to procure sea animals (even if it's only on a yearly basis, when they are most likely to be found beached), hunter-gatherers will preferentially target them, and accumulate them in large numbers. Most critically, the Gibraltar pattern departs significantly from that of those foragers that depend the least on sea critters, which should give one some serious pause.
Stringer et al. (2008: 14323) argue that the presence of sea mammal remains in all the levels of Vanguard Cave and in the Neanderthal and H. sapiens deposits of Gorham's Cave reflects
"that Neanderthals were not only systematically exploiting terrestrial mammals but also marine mollusks, pinnipeds, and cetaceans. Their distribution through the stratigraphy suggests that securing marine mammals was not an accidental or isolated practice, but a focused behavior possibly repeated seasonally or over longer periods... Significantly, the range of species exploited and the age distribution pattern of the prey strongly indicate that the coastal exploitation of resources by Neanderthals was not a sporadic and isolated occurrence but one that required a knowledge of the life history of prey and its seasonality."
Color me skeptical here, and this in spite of my opinion that the behavioral capacities are still systematically underappreciated in contemporary paleoanthropology. But overall, we're talking about numbers of sea animal remains that are absolutely dwarfed by the preponderance of land mammals and that in all cases are significantly rarer than even those of carnivores that occupied the site when humans were absent. Call it what you will, but this is not a behavior that is modern in any real way.
The take-home message here is that, just because some behavior is associated with morphologically 'modern' humans, it does not mean that it is actually modern. In the end, who knows, maybe Neanderthals and early European H. sapiens did exploit sea mammals seasonally - but empirically, the evidence presented by Stringer et al.(2008) rather points to unsystematic, opportunistic acquisition of parts of beached carcasses. But the fact that the Gibraltar data are so odd in light of everything we know about the subsistence patterns of sea-oriented foragers underlines the importance of always defining what is meant by 'modern behavior' and of situating behavioral reconstructions of Neanderthals and early H. sapiens in the broader context of the hunter-gatherer behavioral record. Doing so usually yields some very interesting results indeed!
Kelley, R. L. 1995. The Foraging Spectrum. Smithsonian Institution Press, Washington.
Stringer, C. B., J. C. Finlayson, R. N. E. Barton, Y. Fernandez-Jalvo, I. Caceres, R. C. Sabin, E. J. Rhodes, A. P. Currant, J. Rodriguez-Vidal, F. Giles-Pacheco, J. A. Riquelme-Cantal (2008). From the Cover: Neanderthal exploitation of marine mammals in Gibraltar Proceedings of the National Academy of Sciences, 105 (38), 14319-14324 DOI: 10.1073/pnas.0805474105
Wobst, H. M. 1978. The Archaeo-Ethnology of Hunter-Gatherers or the Tyranny of the ethnographic record in Archaeology. American Antiquity 43:303-309.