CCGL 9042 Lecturer: Dr Stacey Cherny 10 September 2014

1. Lecture 2: Chapter 2, “The collective brain: exchange and specialisation after 200,000 years ago” CCGL 9042 Lecturer: Dr Stacey Cherny 10 September 2014

2. Main points of the chapter • Trade is essential for progress in technology • No species, except, modern humans, Homo sapiens, engages in trade • Progress is achieved with innovation networks---the larger the population and trading network, the more technology advances • The law of comparative advantage explains why trade is beneficial

3. Biface hand axe • Early hominids appear to have made only one stone tool, the “Acheuleanbiface” • The name Acheulean comes from Saint-Acheul, the place in France where some of these axes were found in 1859, and the name was given in 1925 • John Frere appears to be the person who first rediscovered these handaxes in 1797, although being before Darwin’s time, the discovery was largely ignored • Appeared from approximate 1.76 million years ago (Ma) (Homo habilis) to about 285 thousand years ago (Ka) (Homo heidelbergensis) • http://youtu.be/vmanlBDFfw0

4. Boxgrove man • Boxgrove Quarry, West Sussux, England, was excavated starting from 1983, led my Mark Roberts • Roberts & Pitts (1998) Fairweather Eden: Life in Britain half a million years ago as revealed by the excavations at Boxgrove

5. What were the species who used this handaxe like? • Making the same single tool for perhaps 1,000,000 years sounds absurd to us • Essentially the same handaxes were used everywhere these hominids lived; there was little variability in the technology • Interestingly, genetic evolution occurred more rapidly over this period than technological evolution • Hominid brain sizes increased by 1/3 • This isn’t particularly surprising when considering the animal world, however • Species habits seem to never change; if the behavior changes typically that means a new species arose • Dawkin’s coined the term, The Extended Phenotype (and wrote a book by that title), to refer to the behavioral expression of an organism’s genes • The Acheulianhandaxe was part of the hominid extended phenotype • It allowed hominids to butcher and consume meat from large animals, and the protein diet supported larger brains (Aiello & Wheeler, 1995) • The discovery of fire and cooking food allowed gut size to be reduced, further allowing for larger brains • Behavioral changes may have driven biological changes

6. Homo sapiens (Homo dynamicus) • Until Homo sapiens, technological change lagged genetic change • As early as perhaps ~285 Ka, the toolkit of the ancestors (or predecessors) of modern humans started to changeMcBrearty & Brookes, 2000) • This was very gradual and different tools emerged in different places at different times in Africa according to the archeological record • The first Homo sapiens were found to date to 160 Ka in east Africa • Evidence of cooking dates to a similar time, from Pinnacle Point, South Africa (Marean et al, 2007) • Shellfish were cooked • Bladelets for use with spears were made • Red ochre was likely used for decorative purposes • These habits and people seemed to drop in numbers until 130-115 Ka, during the Eemian interglacial period, when the Middle East appears to have been colonized

7. Interglacial period130-115 Ka Retouched tools from Ruhlmann'sAterian assemblage I. Left to right. pedunculate point (quartzite), convergent side scraper, bifacially flaked foliate point, retouched blade (quartzite), pedunculate point. From Barton et al (2009)

8. Interglacial period130-115 Ka Nassarius (snail) shells with man-made holes in them were found in several sites in North Africa dating 82 Ka to 120 Ka Some covered with red ochre This would signify decoration

9. Interglacial period130-115 Ka • Similar shells were found in South Africa with similar dating • These are the earliest evidence of trade, since these shells have been found 25-125 miles from coasts • Obsidian (volcanic glass) has also been found to travel long distances during this period, evidenced from sites in Melka Konture and Porc Epic, both in Ethiopia

10. Beginning to barter • Two theories have been proposed for the emergence of a new set of tools in humans around 80 Ka • Volatile climate in Africa selected for individuals who are highly adaptable • A random genetic mutation arose which allowed for more complex behavior and thought • Volatile climate was not unusual, however, and had existed at many times during early human evolution • Also, other species would have been subjected to the same volatile conditions, yet jumps in their technology aren’t observed • Was a genetic change key to the emergence of language and trade? • Mutations in FOXP2were found that are involved in language in both humans and songbirds • Inserting this mutated gene into mice changes their brains in areas important in language • However, this mutation is also found in Neanderthals, who likely had language but whose toolkit was very primitive and unchanged • Language may be necessary for barter to result, but it is not sufficient

11. Barter in non-humans? • Barter is distinct from reciprocity • Apes and many other animals groom each other, for example, and there is lots of reciprocity in the animal world • The reciprocal behaviors also tend to be universal across species • Reciprocity doesn’t expand the toolkit

12. Barter in non-humans • An attempt to teach chimpanzees barter (Brosnan et al, 2008) • Subjects were 14 adult chimp volunteers • Preferences were established for 4 types of food using a series of forced choice trials • A series of trials where experimenter presented a food for trade in the right hand and gave it to the chimp if the chip gave the experimenter his/her food to the experimenter’s open left hand

13. Barter in non-humans • The chimps could be taught to trade something they liked for something they liked even more in some cases

14. Barter in non-humans • Chimps and monkeys have also been taught to exchange tokens for food • But tokens have no value to them • Non-humans seem unable to trade something they value for something they value even more, which is key to true barter

15. Barter • Ridley concludes that the advanced toolkit came about because humans started to “share, swap, barter, and trade” with other people who weren’t their relatives • This resulted in increased specialization and variation, which leads to increased innovation • Different people specialize in different things • What makes people unique in the animal kingdom is that people exchange things they like for completely different things • There are reasons to exchange a favor now for a favor later, but such exchange doesn’t advance progress • The meme of barter or trade, once established spread rapidly, because it was hugely advantageous • What was the driving force behind humans evolving barter? • One theory is that the discovery of fire and cooking food led to sharing/exchanging of food which was the foundation of barter

16. Hunting for gathering • Cooking led to a sexual division of labour • Kuhn & Stiner (2006) argue that Neanderthals didn’t have a sexual division of labour, but modern humans do • Neanderthal men and women participated in large-game hunting • Isotope studies of Neanderthal bones show no evidence for consumption of plants and also little individual differences (so likely no male/female differences) • Hunter-gatherer might therefore not be a 1 Ma lifestyle, but rather only 200 Ka

17. Modern hunter-gatherers • In the Alyawarre aborigines of Australia, young women tend to the children and older women hunt goanna lizards, while the men hunt kangaroos and emus • So the sexual division of labor seems to also exist in the absence of childcare constraints • When both men and women hunt, it seems that men hunt bigger game than women do Figure 1. Martu gender division of foraging labor (the proportion of calories acquired by women and men in each foraging activity). Activities toward the center line (0 difference in relative proportional contribution, or 50–50 division of labor) are characterized by equal contributions on the part of each gender; those toward the top end are characterized by high women’s contribution and those toward the bottom end by high men’s contribution. The pie charts show the percentage of all men’s and all women’s foraging time spent on each activity.

19. Modern hunter-gatherers • In the Khoisan, “Women demand meat as their social right, and they get it – otherwise they leave their husbands, marry elsewhere or make love to other men” from Women Like Meat • Only humans have a sexual division of labour in terms of types of food collected and sharing what is found

20. Out of Africa • Around 80 Ka, the humans in Africa were far more advanced than those Europe (the ancestors of Neanderthals) • Genetic evidence from the L3 mitochondrial haplogroup suggests a small group of African humans colonized all of Africa and then around 65 Ka expanded into Europe • They displaced and perhaps mated with Neanderthals in Europe (in small numbers) • This is the beginning of modern humans, a people who made a variety of tools and ornamental beads

21. DNA family tree construction • Analysis of mtDNA, which mutates slowly and is maternally inherited (no recombination) allows us to trace our genetic ancestry and through coalescent modeling, determine when the most recent common ancestor of all women lived • mtEVE has been estimated to have lived in Africa around 140 Ka • Y-chromosome Adam has similarly been estimated to originate anywhere from 120-338 Ka

22. Out of Africa expansion BSPs of effective population size through time for (a) sub-Saharan Africa (n=224), (b) haplogroup L0 (n=60), (c) haplogroup L1 (n=41), (d) haplogroup L2 (n=43) and (e) haplogroup L3 (n=80). The bold black line represents the median posterior effective population size through time. The grey lines delimit the 95% highest posterior density for effective population size, accounting for uncertainty in the reconstructed phylogeny and substitution model parameters. The dashed line in (a) plots the sum of the separate lineage population estimates through time. Effective population size is plotted on a log scale and assumes a generation time of 20 years. These estimates of effective population size have an inverse relationship with the evolutionary rate of mtDNA used for the calibration, such that they will be lower for faster rates and higher for slower rates. For comparison, all the x-axes have a scale extending to 150 kyr. The plots are truncated to the median estimate of each region's TMRCA. Genealogy of major African mtDNAhaplogroups. This phylogeny shows the genealogical relationships between the L0, L1, L2 and L3 mtDNA lineages of Africa and the position of the two major non-African lineages, M and N. From Atkinson et al, 2008

23. Out of Africa expansion • 65 Ka humans rapidly expanded along the coast of Asia • They stuck to the beach areas for food • 40 Ka modern humans expanded into Europe and China • These humans were hunting/gathering • They encountered Neaderthals, interbred with them a bit, but mostly just displaced them • Louse DNA studies provide evidence of contact • Neaderthals went extinct around 28 Ka, last found in southern tip of Spain, near Strait of Gilbralter

24. Out of Africa expansion • Initially, humans ate only large mammals and some slow-moving small animals • Then a switch to fast-breeding species occurred • With the human diet consisting of the more plentiful small species, human numbers expanded greatly • The appetite for large game didn’t end, though, and so with greater numbers of humans, they managed to eventually extinguish all large mammals from Europe • Chauvet cave paintings in southern France, 32 Ka, depict rhinoceros • Lascaux art, from 15 Ka, shows only bison, bulls, and horses – the rhinos were extinct by then

25. Out of Africa expansion • Predators rarely wipe out their pray in nature • Typically if prey numbers decline, predator numbers decline – less food supports fewer predators, since a shift in choice of prey just doesn’t happen • Erectus hominids like Neanderthal declined in numbers if large mammals were scarce • The modern out-of-Africa humans, however, by shifting to rapidly reproducing species for their food, increased in numbers and so were in a position to wipe out the large mammals • Humans, after expanding to Australia and the Americas, similarly wiped out the large species there

27. Reich, Paterson, Campbell, et al. Reconstructing Native American population history. Nature 488, 370–374 (16 August 2012) doi:10.1038/nature11258

28. Kuhn & Stiner (2006) Typical ungulate prey: gazelle, deer, wild horses, boar, bison, and wild cattle

29. Kuhn & Stiner (2006) Defense traits: slow game, quickrunning terrestrial mammals, and quickflying birds

30. Shall we trade?Acceleration of trade • Microburin techniques were developed • http://youtu.be/fqIf6JsBZ_0 • 45 Ka, in Western Eurasia, new slim, sharp blades made from rock cores appear • 34 Ka, bone points were used on wooden spears • 26 Ka, needles and therefore string were in use, to make bags, nets for catching prey, etc. • 18 Ka atlatls were developed • http://youtu.be/w_cB9GXw5As

31. Less practical objects Flutes from HohleFelsand Vogelherd from >35 Ka Photomicrographs documenting striations and notches from manufacture and polish from use: a, b, d, incident-light fluorescence mode (ultraviolet- and violet-light excitation); c, e, incident light, obliquely crossed polars, lambda plate. The photomicrographs were made with a Leica DMRX-MPV SP microscope photometer. The long axis of the micrographs is 2.8 mm long.

32. Law of comparative advantage • First described by David Ricardo (1817) in On the Principles of Political Economy and Taxation (at econlib.org) • An individual has a comparative advantage in producing one particular good over another when the opportunity cost of producing it is lower than another individual’s opportunity cost

33. Maximum output for one day of work for Bob and Ann, only occupants of an island • But if they each split their day, they can produce the amounts below, and they each really want to have 25 & 50 bananas per day, respectively.

34. Is there anyway way they can end up with surplus? • For each fish Ann catches, she needs to forgo harvesting one half a banana, while Bob needs to give up a whole banana • Opportunity cost of 1 fish for Ann is ½ banana • Opportunity cost of 1 fish for Bob is is 1 banana • Therefore, Ann has a comparative advantage in fish • For each banana Bob harvests, he needs to forgo catching 1 fish, while Ann needs to give up catching 2 fish • Opportunity cost of 1 banana is 1 fish for Bob • Opportunity cost of 1 banana is 2 fish for Ann • Bob has a comparative advantage in bananas • Even though Ann is better at both fishing and banana harvesting, she sees that she could come out ahead by trading with Bob, and so could Bob, so she offers to sell Bob 37 of her fish for 25 of his bananas, so they will now produce:

35. The result after trade: • Bob has 12 more fish that he would have without trade • Ann has 13 more fish than she would have without trade • 25 fish were caught that wouldn’t have been without trade  trade encourages specialization and produces wealth • Bob would have been ahead getting anything more than 1 fish for each banana • Ann would have been ahead paying any amount less than 2 fish for one banana • That is, the price of fish could be anywhere between .5 and 1 banana for both Ann and Bob to benefit by trade

36. With trade comes innovation • If a person can’t trade, all their time will be spent trying to feed and shelter themselves • The diversity of production did not occur until humans traded • Without trade, any improvements in a particular task will bring only limited benefit, since they must perform many tasks to survive and have little time to improve things, nor little time to make use of the improvements they make • With trade, specialization can result • With specialization, there is more opportunity for improvement in the way things are done • If someone spends their whole day making a particular tool, they will get better at it • There will also be an incentive to invest time/energy into finding more efficient ways to make what they make • As individuals, we maximize what we can have by spending our entire days doing what we have a comparative advantage in

37. Specialization in nature • There is lots of evidence of division of labour in other species, e.g., worker bees and queen bees • There are symbiotic relationship in nature, e.g., between gut bacteria and their hosts in various species, including humans • Of course, all our bodies are made of specialized cells too, so specialization within organisms is the norm • But in all cases, aside from humans, these examples of “trade” or specialization within a species always occur between close relatives and/or the repertoire is very limited, e.g. an extended phenotype

38. Modern-day hunter gatherers • Interestingly, there is little evidence of trade or much specialization in those hunter-gatherer tribes we’ve come across in the modern world • There is always male-female specialization, and tribe leaders or priests, but little else • Could this be a result of harsh conditions leaving little surplus for more advanced specializations to have evolved?

39. Innovation networks • Skills are acquired through imitation, copying what experts do • This requires living in groups large enough to allow for specialization, or living in close enough contact with other groups • Jared Diamond, “Ten Thousand Years of Solitude”, about how primitive Tasmanian life was when Europeans discovered them in 1642 • ~5000 people lived there at that time • Physically, the people looked different than those on the mainland, having wooly rather than straight on wavy hair • They spoke around 5 dialects, none similar to those on the mainland • The walked around naked, even in the winter, in a fairly cold climate • They started fires whenever they stopped moving around, lit by firebrands they carried with them • Apparently they were unable to start fire from scratch • They were hunter/gatherers, with no farming of plants or animals • They had few and primitive tools, and maybe had two dozen types of objects in total • This included a very primitive raft, which would only get them maybe 6 miles before getting waterlogged and sinking • Life was far more advanced on the mainland, where they had boomerangs, spear throwers, mounted stone tools, needles, etc

40. Innovation networks • Humans on Kangaroo Island and Flinders Island likely went extinct after a few thousand years of isolation • The land these peoples occupied was fertile • These populations regressed not because the people in them were inferior to other humans, but because their population sizes were too small---their collective brains could not develop • Contrast to Tierra del Fuego, where when Darwin encountered them in 1834, he found a fairly advanced society • These people lived in a harsher environment than those above • But, they were in regular contact with the outside world • This outside contact sometimes refreshes skills that may have been lost and might also introduce new skills over time

41. Innovation networks – the collective brain • Smaller groups • Result in fewer new inventions – less variation • The inventions are less likely to survive over time because they need to be reproduced by experts and small groups will have fewer experts • Isolation results in inventions not spreading and therefore not increasing in frequency • Inventions in isolated groups are less likely to survive over time • Larger groups • allow for more specialization and increase the chances of new inventions be made – increased variation • They further increase the chances of inventions surviving over time and being improved, by having more experts capable of making them • Large networks • result in the exchange of inventions and ideas – reproduction and recombination • The mating of ideas/inventions will result in better inventions • By sharing inventions across large networks of groups, these inventions will also be more likely to survive over time

42. Main themes • Progress is a result of trade • The larger the collective brain, the more progress you get • What does this imply for our modern world?

43. Trade • What are tariffs? • Taxes imposed on imports or exports • The purpose is generally to make the cost of imported goods relatively more expensive than locally produced goods, to encourage local production and consumption • Why would we want to do that?

44. Innovation in organizations • Given how progress has been achieved historically, what does this suggest for running large organizations which also want to innovate and introduce better products and services?

45. Importance of variation • Adapt: Why success always starts with failure, by Tim Harford • http://youtu.be/KR_mCvb-KyY

46. Comparative advantage in Hong Kong • Different cities and countries often historically specialized in just a few industries, due to some sort of comparative advantage • Why is the Hong Kong economy mostly shipping/logistics and banking (and property development/sales)? • What is the nature of HK’s comparative advantage in these sectors?