Homo Sapiens: Anatomically Modern Humans (AMH)

“There Are No Weaknesses”
The nonexistence of scientific skepticism was only natural since, as Darwin lobbyist Eugenie Scott would say in 2009, “There are no weaknesses in the theory of evolution.” See here for the “The Top Ten Scientific Problems with Biological and Chemical Evolution.”

What’s significant about the Dissent from Darwinism list is not so much the names and the institutions listed there but what they tell you about the many Darwin skeptics in the science world who wouldn’t dare sign. Scientists know the career costs that would come from publicly challenging evolutionary theory. Discovery Institute and its sister research lab, Biologic Institute, have welcomed refugees who were chased out of top spots in the research world. Douglas Axe, Günter Bechly, and Richard Sternberg are well known to Evolution News readers. Check out the Free Science website for other stories.



The Power of Groupthink
The signers of the Dissent list have all risked their careers or reputations in signing. Such is the power of groupthink. The scientific mainstream will punish you if they can, and the media is wedded to its narrative that “the scientists” are all in agreement and only “poets,” “lawyers,” and other “daft rubes” doubt Darwinian theory. In fact, I’m currently seeking to place an awesome manuscript by a scientist at an Ivy League university with the guts to give his reasons for rejecting Darwinism. The problem is that, as yet, nobody has the guts to publish it.

Other scientists, like the Third Way group or the researchers who met at the Royal Society in 2016, reject standard evolutionary theory but would not sign the Dissent list because they (mistakenly) think it conveys an even worse source of ritual contamination — the taint of intelligent design. In fact, the Dissent text doesn’t in any way imply support for ID, as the website’s FAQ page emphasizes. The simple observation that neo-Darwinism can’t explain the origin of complex life forms does not lead directly to a design inference. That is a separate argument with separate evidence. Every ID proponent is a Darwin doubter, but not every Darwin doubter is an ID proponent.



Nothing to Lose?
But I understand why people fear to go public, even if they would seem to have nothing to lose. I recall a visit a colleague and I made to the office of a Nobel laureate in a relevant field who gruffly stated his own rejection of evolutionary theory but refused to say anything in public. He is not a young man. Given his senior status, you would think he’d have nothing to fear. Yet he was afraid.

Some people don’t know when they should be afraid. Indeed, it’s a yearly thing at the Summer Seminars on Intelligent Design, held in Seattle primarily for undergraduate and graduate students, that we need to warn the participants not to take the perils lightly. They should not, for example, post news about the Seminar or photos of other students on social media. We’ve had panics about PhD students who acted incautiously. In fact, we had one just last week.

But by the time you’ve advanced a little further in academic life, you likely know what’s good for you. Given all this – the fear of taint and reprisals – it follows inevitably that the 1,000+ names represent only the tip of a vast iceberg. For every name, you can assigner a multiplier. Would it be ten? A hundred? More? I don’t know.



A Skeptical “Underground”
Physicist Brian Miller, Research Coordinator for the Center for Science & Culture, has written about what he calls an “underground” in academia. Again, ID sympathizers are a subset of Darwin skeptics. But Dr. Miller observed:

A biologist in our network worked as a postdoctoral researcher at Harvard. He recounted how about a quarter of the postdocs he encountered were at least sympathetic to design arguments, but none were willing to acknowledge their support publicly due to the likely repercussions.

Westernmost Europe constitutes a key location in determining the timing of the replacement of Neanderthals by anatomically modern humans (AMHs). In this study, the replacement of late Mousterian industries by Aurignacian ones at the site of Bajondillo Cave (Málaga, southern Spain) is reported. On the basis of Bayesian analyses, a total of 26 radiocarbon dates, including 17 new ones, show that replacement at Bajondillo took place in the millennia centring on ~45–43 calibrated thousand years before the present (cal ka BP)—well before the onset of Heinrich event 4 (~40.2–38.3 cal ka BP). These dates indicate that the arrival of AMHs at the southernmost tip of Iberia was essentially synchronous with that recorded in other regions of Europe, and significantly increases the areal expansion reached by early AMHs at that time. In agreement with human dispersal scenarios on other continents, such rapid expansion points to coastal corridors as favoured routes for early AMH. The new radiocarbon dates align Iberian chronologies with AMH dispersal patterns in Eurasia.



The new Bajondillo dates are crucial for several reasons. First, they confirm the presence of a chronologically early Aurignacian in southern Iberia at ~43 cal ka that now shows the first appear-ance of the EUP to be an essentially synchronous event throughout Europe (Fig. 3 and Supplementary Fig. 3). This suggests that the dis-persal of AMHs was much faster than hitherto postulated, and the expansion of the earliest Aurignacians in Europe is now increased westwards by > 1,000 km. These dates thus call into question both the gradual ‘wave-of-advance’ and the ‘Ebro frontier’ models. They also provide reference points for the attribution of early art work in Iberian caves—something that remains highly controversial35. The dates suggest either extremely high mobility of early Aurignacians or well-developed networks of interchange. For early AMHs, rapid dispersal was seemingly only possible over essentially ‘empty’ terri-tories (that is, either completely depopulated areas, as some studies suggest for southern Iberia at the time7, or areas featuring severely depleted human populations).


Fig. 3: Comparison between the chronologies of the different archaeological levels at Bajondillo Cave and a selection of palaeoenvironmental proxies.

The Aurignacian early expansion took place between Heinrich events 5 and 4 (Fig. 3 and Supplementary Fig. 3), when cold and steppic conditions prevailed throughout most of western Europe, including the Iberian hinterland36. In light of this, it might be no coincidence that a prevalence of European EUP sites has been reported along shores or neighbouring lowlands where milder con-ditions prevailed and more productive environments, in terms of living resources, existed (Fig. 1 and Supplementary Fig. 2c). The Aurignacian from Bajondillo Cave conforms with this pattern and is not an isolated case in Iberia, where newly recorded Aurignacian sites south of the Ebro river, such as Foradada16, Cendres17 and Pego do Diabo12, are all located on the present-day coast or its adjoin-ing lowlands (Fig. 1), nor in Italy (Riparo Mochi and Serino; see Supplementary Information). Coasts and coastal lowlands as instrumental for human dispersal and colonizing events are not a phenomenon restricted to the European Aurignacian, since data emerging from southern Arabia37, Australia38,39 and South America40 all point in the same direction. In eastern and southern Iberia, trav-elling through coasts and coastal lowlands would have been con-siderably easier than travelling through one of the most rugged and mountainous hinterlands in Europe. The enhanced mobility of Aurignacian populations can be inferred from their swift spread over western Europe from Glacial Interstadial 12 onwards, thus hinting at dispersals taking place across territories that were easy to traverse (Supplementary Fig. 2a,b)1.



The onset of the Aurignacian cannot be detached from the demise of the Neanderthals. Inferences about the mobility and settlement patterns of southern Iberian Neanderthals are compli-cated due to the restricted number of Mousterian sites, as well as the prevalence of low sea-level stands during this period, which means that an undetermined, yet probably substantial, fraction of the evidence presently lies underwater. From this perspective Bajondillo Cave is of great relevance since, due to its topogra-phy, it was at all times located on or very close to the shore (that is, not more than 5 km distant; Supplementary Fig. 2a), but never flooded. The data from Bajondillo Cave and other coastal Iberian locations41 reveal that stasis, as exemplified by around 120 kyr14 of Neanderthal occupation with no clear traces of technological devel-opments, prevailed during the Iberian Mousterian. Similar trends are also documented—albeit in in a more restricted manner—at the Abrigo 3 (ref. 21) and Gorham’s Cave sites11. All constitute evi-dence that Neanderthals were settled along the coast well before the onset of the Aurignacian. Although the Bajondillo Cave dates do not indicate any coexistence of Neanderthals and Aurignacians, the fact that the Middle Palaeolithic ceases at around 45 cal ka (Supplementary Table 1) is also worth noting. Indeed, this date is essentially synchronous with the cessation of Middle Palaeolithic levels from sites in the province of Málaga, both coastal (Abrigo 3)21 and inland (Zafarraya)22. The idea of a regional, as opposed to local, phenomenon seems compelling, as is the fact that (except for the two Bay of Málaga sites) Late Mousterian settlements are located at a substantial altitude (that is, > 400 m). A putative preferential location of late Neanderthal sites on harsher and less productive habitats than the coastal zones where older Middle Palaeolithic sites occur and the earliest AMH sites are recorded hints at a scenario of competitive displacement of Neanderthals by AMHs. This com-plex issue is difficult to address when a substantial proportion of the available evidence is circumstantial.

In contrast, genetic data may help confirm whether Neanderthal replacement was determined by competition, migration and random species drift or if, as also seems possible, AMHs and Neanderthal gene pools coalesced after episodes of introgression42. However, it is notable that none of the European late Neanderthal genomes sequenced so far shows evi-dence of interbreeding with AMHs43.Recent reviews highlighting the genetic complexities that under-lie AMH expansion in Eurasia tend to focus on data from Asia, and fail to consider the possibility that a crucial part of that evidence may lie on the westernmost tip of the Mediterranean2. Given the relevance of the palaeoanthropological and archaeological data that are slowly emerging from this region, further efforts to determine whether coastal dispersals played a major role in the arrival of mod-ern humans in the region are crucial. Given the growing evidence that humans were also capable of crossing bodies of water before 50 cal k 2, investigation into whether the Strait of Gibraltar played any role as a connector of European Neanderthals and North African AMHs is also a promising area of research. It is within this interpretative framework that the presence of an early Aurignacian at Bajondillo Cave may bear wider implications for the origin of Upper Palaeolithic industries and the appearance of AMHs in the European subcontinent than can be foreseen now.

Nature Ecology & Evolutionvolume 3, pages207–212 (2019)