De las reglas del vestir a la cotidianidad

literature contains, or how best to classify them. Counts vary from as low as six or seven to as high as a hundred, and typologies also vary greatly. There are four main reasons for this situation.

Reviewers, for a start, mean different things by ‘models of bipedalism’. For some, they are original explanatory frameworks for the earliest bipedalism. For others, they can include unelaborated statements about possible selection pressures, endorsements or positive tests of others’ hypotheses, hypotheses about pressures for

modern-human-like bipedalism, and relevant observations of non-human primates. In a much-cited review, Rose (1991), for example, ranged more broadly than most and construed brief comments by E. Reynolds (1931) as an

‘evasion argument’ and observations of captive chimpanzees by Köhler (1959) as a ‘walking on snow or mud’ argument (Rose 1991:41). By ‘model’ some reviewers also mean a whole class of explanations, such as ‘carrying’, while others mean simply an explanation generated by one individual author or team.

What distinguishes one type of model from another has also, like the interpretation of the word itself, been subjective. Fleagle, for instance, (1998:526) separated ‘carrying’ from ‘provisioning family’; Niemitz (2010:247) used one category for both. Conroy (2005:272) separated ‘behaviors such as carrying food and infants and using the hands for display’ from ‘bipedal threat/appeasement

Further complicating the process of counting and classifying is the fact that models of precursor hominin locomotion have sometimes been counted together with models of selection pressures, and sometimes conceptually separated. Richmond et al’.’s (2001) review contrasts in this regard with, for example, Stanford’s (2003).

Reviewers have also frequently decided that some models are obsolete or marginal, and have enumerated and classified only ‘the important ones’. Rarely, however, have they agreed about which these are, and a major reason is that most reviews have been either backgrounds to their authors’ own models or backgrounds to their endorsements of particular types.

A brief look at six reviews illustrates some of the confusion. Rose (1991) listed 20 model types generated by 41 (not exhaustive) authors and divided these types into four blocs. He separately listed 14 different postulated types of precursor posture and locomotion. Richmond et al. (2001) focussed on precursor locomotion and listed five different types, as well as 12 (not exhaustive) selection pressure models. They argued for an inseparable

relationship between the two. Stanford (2003) discussed six “prominent” models. Harcourt-Smith (2007) identified seven “important” hypotheses from the last 40 years but his hypotheses were not the same as Stanford’s. Niemitz

(2010) claimed, but did not enumerate, 30 models and reviewed the 11 “most important and recent ones”

(2010:214), which were not the same as Harcourt-Smith’s or Stanford’s, and Kingdon (2003) suggested 13 models, also not the same. Five of these six reviews were the backgrounds to their authors’ models; the other (Harcourt- Smith) backgrounded an endorsement of a particular type. Rose positioned his own model in the category ‘combination

of factors’ (1991:41), but Niemitz placed Rose’s model in the category ‘reaching for food’ (2010:247).

Adding to the confusion is the fact that reviewers have rarely, even in the briefest of terms, explained what they actually mean by model or what their criteria are for creating categories.

The criteria used in the present review were stated in chapter 2. Using these criteria, 12 model types can be identified (which are not the same as those in the reviews mentioned above): Carrying; Conserving Energy; Cooling; Encephalization; Exaptive Arboreality; Pathology; Predation without tools: Sitting; Standing; Standing-and-shuffling; Versatility; and Water. Some of these types can be sub- divided into variants and sub-variants (Table 1).

Seventy-six individual models are included in Table 1, drawn from 121 primary sources (which are not exhaustive of their authors’ output on bipedalism). The hypotheses contained within each of the 71 models deemed current are stated in the relevant test sections of the thesis (chapters 9 – 17). Sub-section 3.1 below reviews the model types, and also states the hypotheses for obsolete models and the reasons why they can be considered falsified. An overview of the major features of the literature is provided in sub- section 3.2, and the role of infants is discussed and quantified in sub-section 3.3.

Table 1. Classification scheme for models of bipedalism

Mod# Type Variant type Sub-variant type Author/s

1 CARRYING Food Hewes 1961

2 CARRYING Food Tanner and Zihlman 1976, Zihlman and Tanner 1978

3 CARRYING Food Lancaster 1978

4 CARRYING Food Lovejoy 1981, 2009

5 CARRYING Food Fisher 1982

6 CARRYING Food Hill 1982

7 CARRYING Food Parker 1987

8 CARRYING Infants Iwamoto 1985

9 CARRYING Infants Sinclair et al. 1986

10 CARRYING Infants Amaral 1989, 2008

11 CARRYING Infants Sutou 2012, 2013, 2014

12 CARRYING Tools for Defence Hockett and Ascher 1964

13 CARRYING Tools for Defence Washburn 1967

14 CARRYING Tools for Defence Ardrey 1976

15 CARRYING Tools for Defence Kortlandt 1980

16 CARRYING Tools for Defence Kelly 2001

17 CARRYING Tools for Scavenging Shipman 1984, 1986 18 CARRYING Tools for Hunting Etkin 1954

Table 1 (cont…)

Mod# Type Variant type Sub-variant type Author/s

19 CARRYING Tools for Hunting Morris 1967

20 CARRYING Tools for Hunting Merker 1984

21 CARRYING Tools for Gathering Bartholomew and Birdsell 1953 22 CARRYING Tools for Gathering Tanner 1981

23 CONSERVING ENERGY Rodman and McHenry 1980

24 CONSERVING ENERGY Senut 1992

25 CONSERVING ENERGY Isbell and Young 1996

26 CONSERVING ENERGY Leonard and Robertson 1997

27 CONSERVING ENERGY Foley and Elton 1998

28 COOLING Wheeler 1984, 1985, 1988, 1991a, 1991b

29 ENCEPHALIZATION Elliot Smith 1924 (obsolete model type)

30 EXAPTIVE ARBOREALITY Primitive biped Wood Jones 1918 (obsolete model) 31 EXAPTIVE ARBOREALITY Primitive biped Morton 1926

Table 1 (cont…)

Mod# Type Variant type Sub-variant type Author/s 32 EXAPTIVE ARBOREALITY Primitive biped Gregory 1927

33 EXAPTIVE ARBOREALITY Primitive biped Tuttle 1969, 1974, 1981 34 EXAPTIVE ARBOREALITY Primitive biped Stern 1975

35 EXAPTIVE ARBOREALITY Primitive biped Thorpe et al. 2007, 2014, Crompton et al. 2008, 2010

36 EXAPTIVE ARBOREALITY Primitive biped Senut et al. 2017 37 EXAPTIVE ARBOREALITY Locom. decoup. Sylvester 2006

38 PATHOLOGY Marrett 1936 (obsolete model type)

39 PREDATION WITHOUT TOOLS Terrestrial Read 1925 (obsolete model type)

40 PREDATION WITHOUT TOOLS Arboreal Eickhoff 1988 (obsolete model type)

41 SITTING Seed-eating Jolly 1970, 1972, Jolly and Plog 1987

42 SITTING Squat-feeding Kingdon 2003

43 STANDING Defence Walter 2004

Table 1 (cont…)

Mod# Type Variant type Sub-variant type Author/s

45 STANDING Feeding Stanford 2002, 2006

46 STANDING Fighting Carrier 2004, 2007, 2011

47 STANDING Tool use Darwin 1874 [1871]

48 STANDING Tool use Dart 1953, 1959

49 STANDING Tool use Marzke 1986

50 STANDING Tool use Fifer 1987

51 STANDING Vigilance Ravey 1978

52 STANDING Display Livingstone 1962

53 STANDING Display Westcott 1967

54 STANDING Display Guthrie 1970

55 STANDING Display Jablonski and Chaplin 1992, 1993

56 STANDING Display Ishida 2006

57 STANDING SHUFFLING Rose 1976, 1984, 1991

58 STANDING SHUFFLING Geist 1978

59 STANDING SHUFFLING Wrangham 1980

60 STANDING SHUFFLING Hunt 1994, 1996

Table 1 (cont…)

Mod# Type Variant type Sub-variant type Author/s 62 VERSATILITY Mult. Advantages Sigmon 1971 63 VERSATILITY Mult. Advantages Robinson 1972

64 VERSATILITY Mult. Advantages Day 1986

65 VERSATILITY Variability Selec. Potts 1998a, 1998b

66 WATER Wading Niemitz 2002, 2010

67 WATER Wading Wrangham 2005, Wrangham et al. 2009

68 WATER Wading Kuliukas 2011

69 WATER Aquatic Ape Hypothesis (AAH) Hardy 1960, 1977

70 WATER AAH Morgan 1972, 1982, 1990, 1991, 1994, 1997

71 WATER AAH Verhaegen 1985, 1987, 1991a, 1991b, 1993

Verhaegen et al. 2002, 2007, 2011

72 WATER AAH Ellis 1986, 1991, 1993, 1995

73 WATER AAH La Lumiere 1991

74 WATER AAH Schagatay 1991, 2014

75 WATER AAH Odent 2011