behaviour

"...the behaviour of most present day humans remains moderated by magical thinking-type mental processes (lack of integration between the left prefrontal cortical areas and memory), underwritten by sub-optimal cause and effect perception."

Robert G. Bednarik, An aetiology of hominin behaviour, Homo, 2012

Monday, 17 July 2017

On Chris Stringer’s Tsunami Theory

Periscope streamed a live question and answer with Chris Stringer from the National History Museum over Twitter on 26th June this year [1]. The full video can be watched here:


Frustrated by the predictable narrative Stringer was presenting I submitted several questions via Periscope.  One of these was selected and slightly miscommunicated.

Anticipating that Stringer would have to concede that early Pleistocene hominins were capable of complex tasks comparable to those undertaken by extant hominins I asked:

“How did hominins reach Flores 840,000 years ago if it was not by boat?”

His answer, which I did not anticipate, can be seen twenty one minutes into the video. Here is a transcript of his response:

“Well that’s a very good question too because we don’t know.

We think that lineage arrived probably more than a million years ago on the island of Flores. And the usual assumption is that you’d have to have boats to get there because this island was never connected to the rest of South-East Asia there was always deep water, but one possibility is rafting on debris.

Now it may seem extraordinary but of course that tsunami a few years ago in Asia, people were found out at sea 100 miles away from where they had started, out at sea on clumps of vegetation a week later.

So this is a tectonically very active area. When you’ve got tens of thousands or hundreds of thousands of years to play with, is it possible that the ancestors of Homo floresiensis were in some mango swamps foraging, a tidal wave came along and ripped that away and, somehow deposited them over on Flores? That’s a possibility.
Having boats, well you couldn’t exclude it but I think it is much less likely for creatures with very small brains that are much more primitive.”

To summarise:

·        Stringer suggests that given hundreds of thousands of years the odds are more favourable that hominins populated Flores following a freak accident(s) involving a tsunami like wave and a clump of vegetation rather than the possibility of arriving by boat.

·        He claims that their brains were very small and more primitive in support of his proposition that boat building was beyond their capabilities.


Background

Running between Bali and Lombok is the Wallace Line - the most important biogeographical barrier (or filter) in the world. Geologically the islands from Lombok to the east are relatively young having only formed a few million years ago when the Australian plate slid under the Asian plate. They were never part of any other landmass. Evidence for Lower and Middle Pleistocene occupation beyond the Wallace Line by hominins is not limited to Flores but also includes three islands of Nusa Tenggara, Roti, Selatan, and Timor. The stone tools of Flores are up to 840,000 years old. Although this had been reported as far back as 1958 it has only been in recent decades that academics have become aware of this fact due primarily to the work of Bednarik [2,3].


Small brains

Stringer seems to imply that the so-called Hobbit arrived on Flores in its small size rather than as a result of insular dwarfism. Ignoring this lapse in thinking and giving Stringer the benefit of doubt we will assume here that he refers to the small brain volume of Homo erectus one million years ago.

Perhaps Stringer is unaware that modern aborigines’ brain volumes are comparable to Homo erectus. Would he suggest that they too would not be capable of maritime colonization? How would he explain a small brained child achieving a high IQ? The na├»ve idea that brain volume can be simplistically correlated with an abstract, observer-relative and etic measure of intelligence or cognitive ability is surely long surpassed? This one-dimensional view does not even withstand rudimentary testing. Numerous cases reported in scientific journals report patients with substantial parts of their brain missing being able to function normally. Furthermore, a scientifically informed model of early hominin evolution suggests that by the Early Pleistocene the neural architecture that is largely responsible for moderating behaviour patterns was already firmly in place [4–10].

Modern human brain volumes are, on average, approximately 13% smaller than so-called Neanderthals (robust hominins) living 50,000 years ago [3,11]. Applying his “small brain” logic to his own hypothesis that Neanderthals were cognitively inferior to ‘modern humans’ Stringer needs to explain what evolutionary advantage would lead to robust hominins having significantly larger brains than extant hominins if they were mostly redundant?


Floating on a mat

Stringer is not the first person to put forward the idea of the floating vegetation mat. Regrettably, it appears that the more common (and dare I suggest more comfortable) “assumption” of some academics in the fields of Palaeoanthropology and Pleistocene archaeology, is the stance perpetuated by Stringer here.

There are various problems with his theory not least of which is that no other large land mammal has crossed the Wallace Line in this way. If large-bodied hominins could float across on vegetation mats then many other species could too. There are hundreds of such possible species, many of which are far better natural swimmers than extant hominins, but none have crossed the Wallace Line. Proboscideans have crossed the Wallace Line, but not on vegetation mats. They are excellent swimmers and hence also maritime colonisers [2,3].

More importantly perhaps, sea-narrows by their very nature cannot be crossed simply by drifting. The passage from Bali to Flores is not simple. It would either have been made first from Bali to Lombok and then from Lombok, to Sumbawa, and then Komodo, or alternatively via Selatan. The distance from Bali to Lombok would always have been at least 30km at any time during the Pleistocene. All these crossings require watercraft, and in all cases the opposite shore line would have been visible from departure [3].


A genetically viable population

The colonisation of islands by hominins is demonstrated throughout the Pleistocene. Skeletal evidence comes from at least nine individuals from Sardinia, Crete, Santa Rosa, Okinawa and also several hundred from Australia. The settlement of over 20 islands known so far points to a long tradition of sea-faring during this period. The maximal distances crossed can be seen to increase steadily over the course of time culminating in crossings over 200km by 50-60,000 years ago [2,3].

However, the most damning indictment of Stringer’s theory is that it does not account for population viability. It requires more than a few chance survivors of a tsunami to establish a viable breeding population on an island. It would require many reproductively viable males and females to found and sustain a population of sufficient genetic diversity to prevent collapse within several generations. At this point it becomes fully apparent that the “floating vegetation mat theory” sinks against the odds.

Even if we suppose that the extraordinary situation of a tsunami occurred in this region on multiple occasions during the Pleistocene, contra Stringer, the depth of time (“hundreds of thousands of years to play with”) only increases the statistical odds against the possibility that such unlikely events may have overlapped sufficiently to supply the island with enough genetic diversity over time to sustain a breeding population.


Conclusion

The transportation of sufficient numbers of Pleistocene people to colonise the island of Flores 840,000 years ago is very unlikely to have occurred by a freak accident involving a tidal wave and a vegetation mat. In fact, the colonisation of islands beyond the Wallace Line serve as one of the few reliable objective technological indices by which the capacity for innovation and creativity in hominins may be ascertained with some certainty during the Pleistocene.

Stringer has portrayed an extremely unlikely, and unsupported, scenario as more probable than the well supported case for maritime exploration and colonisation. The question is why? The answer lies in the teleological narrative for “modern humans” and “modern human behaviour” Stringer espouses. Evidence which contradicts this narrative cannot be accommodated and thus has to be rejected no matter how unlikely the alternatively proposed scenarios are.


References:
1. Richardson, A. The Neanderthal Within Us; #NHM_Live;.
2. Bednarik, R. G. The maritime dispersal of Pleistocene humans. Migr. Diffus. 2002, 3, 6–33.
3. Bednarik, R. G. The human condition; Developments in primatology; Springer: New York, 2011; ISBN 978-1-4419-9352-6.
4. The psychology of human behavior; Bednarik, R. G., Ed.; Nova Science Publisher’s, Inc: Hauppauge, N.Y, 2013; ISBN 978-1-62257-901-3.
5. Hodgson, D. The symmetry of Acheulean handaxes and cognitive evolution. J. Archaeol. Sci. Rep. 2015, 2, 204–208, doi:10.1016/j.jasrep.2015.02.002.
6. Hodgson, D. The Earliest Manifestations of “Art”: An Attempted Integration. In Exploring the Mind of Ancient Man (Festschrift to Robert G. Bednarik); P Reddy, Ed.; Research India Press: New Dehli, 2005; pp. 25–34.
7. Hodgson, D.; Helvenston, P. A. The Emergence of the Representation of Animals in Palaeoart: Insights from evolution and the cognitive, limbic and visual systems of the human brain. Rock Art Res. J. Aust. Rock Art Res. Assoc. AURA 2006, 23, 3–40.
8. Bednarik, R. G. Beads and Cognitive Evolution. Time Mind 2008, 1, 285–317, doi:10.2752/175169708X329354.
9. Bednarik, R. G. Hominin Mind and Creativity. In The Genesis of Creativity and the Origin of the Human Mind; Putova, B., Ed.; Charles University in Prague, 2015.
10. Bednarik, R. G. Doing with less: Hominin brain atrophy. HOMO - J. Comp. Hum. Biol. 2014, 65, 433–449, doi:10.1016/j.jchb.2014.06.001.
11. Henneberg, M. Decrease of human skull size in the Holocene. Hum. Biol. 1988, 60, 395–405.


Monday, 20 February 2017

Neoteny, Manipulation and Bipedalism

This is the abstract from an unpublished manuscript I wrote quite a while back (2015). The full article can be downloaded from Academia.edu

https://www.academia.edu/31526740/Neoteny_Manipulation_and_Bipedalism



Abstract: Although there are many established hypotheses for bipedalism in hominins none satisfactorily explain the basis for this development but rather propose different explanations or motives for increasingly sustained periods of bipedal behavior. The proposition here differs by suggesting an ontogenetic basis for extended periods of bipedal locomotion. This theory parsimoniously explains the underlying reason for the establishment of bipedalism by placing this particular adaptation within the context of the neotenous developmental trajectory of hominins. It is proposed that neotenous development and the plasticity this process afforded provided the platform upon which adaptations of the forelimbs supported increasingly refined manipulation. Natural selection for the advantages of increased dexterity likely resulted in further retardation of the hominin lineage by tending toward favouring progressively more neotenous hands. In parallel, increasingly neotenous feet demanded more sustained periods of bipedalism which indirectly conferred further self-selective advantages by freeing the hands for longer periods of time. Morphological evolvability conferred by neoteny may underlie both the evolution of the human hand and the subsequent transition toward obligated bipedal locomotion. Ultimately it was adoption of a bipedal stance which supported the accelerated encephalization maintained over the course of several million years until the fairly recent “self-domestication” of our species rapidly reversed this trend.

Keywords: bipedalism; encephalization; ontogeny; manipulation; neoteny


Wednesday, 3 February 2016

Figure-stones at the Rijksmuseum

A good friend of mine alerted me to the Rijksmuseum whom now have a display of figure-stones from Fontmaure in the entrance hall. Whilst they are perhaps not all of the highest quality that I have observed from this particular occupation site (see my web site for more) this is a welcome move from a prestigious centre. It is time that the debate concerning the incorporation of exograms in lithics is moved on from the knee-jerk reaction to dismiss the idea as incredulous as many commentators still do.

The figure-stone exhibition is open for viewing until March 13th 2016.

Larger images of three of the artefacts are available on the Rijksmuseum web site.

http://www.rmo.nl/tentoonstellingen/figuurstenen

Thursday, 10 December 2015

Reflectance Transformation Imaging - Update 2

Finally! The marbles arrived, sphere detection worked and I have created my first RTI....

Some snapshots


Using the HSS Fitter with specular enhancement




And then with the PTM algorithm....

Static Multi Light


Coefficient Unsharp Masking


Image Unsharp Masking


I've uploaded a couple of ptm files to my website http://www.palaeoart.com (beware they are large files) for anyone interested in seeing the end result. Additionally the first eight or so pictures were rendered from PTMs and then cut out in Adobe Photoshop.

I have also reduced the overall processing time by using only PTMfitter in conjunction with a single 'lp' (light profile) file. I am quietly pleased with the dome - it does everything I wanted it to do.

Finally, a photo of the finished dome - with protective covering.





Monday, 7 December 2015

Reflectance Transformation Imaging - Update

Finally working. Some issues tackled in the process, including:

The Canon EOS Utility doesn't work on my Windows 10 platform (it appears that I am not alone in this experience). I eventually resigned myself to finding an alternative piece of software to capture and control images directly from the camera.

I made a bracket that I plan can be modified if I use a different camera. 



I changed the configuration of the LEDs slightly. Originally evenly spaced at 10, 30, 50 and 70 degrees, I've moved the top row down to 65 and the bottom row up to 15 - according to CHI the optimum angles at which to set exposure and aperture settings. The picture below shows the dome after these mods.


I did a trial run and found that sphere detection in the Builder process wouldn't work.... Presumably because the black sphere (a pool ball) was too big relative to the highlights. I will test this assumption when the black marbles I have ordered arrive.

Back soon.



Tuesday, 3 November 2015

Reflectance Transformation Imaging - Dome construction

Today my Cree LEDs and Arduino-type board arrived in the post, closely followed by the 600mm diameter acrylic dome.

Let the build begin....


600mm acrylic dome with flange, 4mm.


Arduino clone


Cree LEDs. I've gone for 4v through the hole for this initial prototype, sacrificing shorter exposure times since I understand the primary constraining factor will be the speed at which the camera will save pictures in RAW format.


Marking the dome up. This dome will have 48 LEDs, so there are four rows of lights. From the top 8, 12, 16 and 12 in the bottom row.


All 48 holes marked up.


This is the clone wired up to the bread-board with three LEDs to test my programming skills! Wired to the board, the jack end of the remote (now cut in two) successfully focuses and then triggers the shutter whilst each LED is lit in turn. I plan to use the remote switch to a) start the sequence or b) manually advance through the sequence.


LEDs and resistors soldered to boards.


Drilling holes into the dome. A jig is used to obtain the correct angle.


Soldering the ground...


And the live wire


Ta-da! Camera hole cut and first coat of black.


Wired up, painted and the clone is in a case... Next step is to test (and debug I expect).






Wednesday, 1 July 2015

Neanderthal Art II

Now closed. An exhibition of figure-stones and Mousterian tools from the Palaeolithic site of Fontmaure in France.


Watford Museum,
194 High Street,
Watford
Hertfordshire
WD17 2DT

Opening times: Thursday-Saturday 10:00-17:00
Free Admission