MAJOR PUBLICATIONS
1. Jablonski, N.G. and Chaplin, G. Becoming bipedal:
How do theories of bipedalization stand up to anatomical scrutiny? In:
Anapol, F., German, R.Z., and Jablonski, N.G., (eds.) Shaping Primate
Evolution: Form, Function and Behavior. Cambridge: Cambridge
University Press, pp. 281-296.
2. Jablonski, N.G., Chaplin, G., and McNamara, K.J.
(2001) Natural selection and the evolution of hominid patterns of growth
and development. In: Minugh-Purvis, N. and McNamara, K.J., (eds.) Human
Evolution through Developmental Change. Baltimore: The Johns Hopkins
University Press, pp. 189-206.
3. Chaplin, G., Jablonski, N.G., and Cable, N.T. (1994)
Physiology, thermoregulation and bipedalism. J. Hum. Evol. 27:497-510.
4. Jablonski, N.G. and Chaplin, G. (1993) Origin of habitual terrestrial
bipedalism in the ancestor of the Hominidae. J. Hum. Evol. 24:259-280.
5. Jablonski, N.G. and Chaplin, G. (1992) The origin of
hominid bipedalism re-examined. Archaeol. Oceania 29:115-125. |
KEY PUBLICATION
JABLONSKI, NINA G. AND GEORGE CHAPLIN. Origin of habitual terrestrial
bipedalism in the ancestor of the Hominidae. Journal of Human
Evolution 24(4):259-280.
ABSTRACT
In this paper, the evolution of habitual terrestrial
bipedalism in the stem proto-hominid is reconstructed through an
examination of historical transformations of shared derived
morphological-behavioural complexes related to bipedalism in catarrhines.
This historical reconstruction indicates that the bipedal threat
display-appeasement behaviour complex may be of particular importance in
understanding the origin of habitual terrestrial bipedalism because it is
the most recently acquired morphological-behavioural complex shared by
the African great apes and humans.
We suggest that in the late middle and late Miocene of East Africa, as
habitats were becoming more open and desiccated and resources more widely
separated, increased intraspecific competition among pre-hominids for
resources ensued. We propose that bipedal displays and their appeasement
were the behaviours essential to the success of pre-hominids in this
environment in that they allowed for the relatively peaceful resolution
of intragroup and intraspecific conflicts. This theory provides a major,
proximate pre-adaptive cause for the later adoption of bipedalism by
proposing the use of an existing behaviour in a new environmental
context, namely increased use of, and deference to bipedal displays to
mitigate violence and make possible the equitable allocation of scarce
resources. It is suggested that this increased the evolutionary fitness
of pre-hominids by removing a major cause of morbidity and mortality
observed in living African apes, i.e. intra- and intergroup aggression.
This theory of the origin of habitual terrestrial bipedalism in the
ancestor of the Hominidae differs from others in that it is consistent
with available environmental, palaeontological, anatomical and
behavioural evidence and known types of social organization in extant
hominoids.
Bipedal postures, once adopted for social control, would have become
common elements of the pre-hominid locomotor repertoire. With time, this
new locomotor mode would have become increasingly multifunctional. |
