Notes - Empty Hands, Open Arms - page 183

32 It eventually covered Elizabeth A. Kellogg, “Evolutionary History of the Grasses,” Plant
Physiology 125 no. 3 (March 2001): 1198-1205, http://www.plantphysiol.org/content/125/3/
1198.full .
32 This dry habitat Cowlishaw and Dunbar, Primate Conservation Biology , 20.
32 And as rainforests shrank A number of other extinction events occurred during this period. The
most notable and the one that appears to have eliminated primates from North America, Europe,
and Asia was the Eocene-Oligocene extinction event 33.9 million years ago, also known as the
Grande Coupure.
32 One strong theory L. Alis Temerin and John G. H. Cant, “The Evolutionary Divergence of Old
World Monkeys and Apes,” The American Naturalist 122 no. 3 (September 1983): 335-51.
32 With an average body weight T. Geissmann, “Body Weight in Wild Gibbons (Hylobatidae),”
in Abstracts, XVIIth Congress of the International Primatological Society, August 10-14, 1998,
abstract no. 282, University of Antananarivo, Madagascar,. http://www.gibbons.de/main/congress/
98madagascar.html .
32 Such abilities no doubt Temerin and Cant, “The Evolutionary Divergence of Old World Mon-
keys and Apes,” The America Naturalist .
32 Gibbons also lack tails Takayoshi Kano explains: “Brachiation is a form of locomotion in
which an animal hangs by its arms from a branch and moves by swinging or alternating the arms.
A relatively heavy animal can move and feed in the trees because brachiation redistributes body
weight. The complete lack of a tail in apes is related to the change in brachiation: monkeys use the
tail for balance when leaping and running, whereas brachiation does not require one. The shoulder,
elbow, and wrist joints of apes are flexible and can rotate to a high degree. From a hanging posi-
tion, various courses of movement are possible” ( The Last Ape , 9).
33 With diversifying monkey species Masato Nakatsukasa and Yutaka Kunimatsu,
“Nacholapithecus and Its Importance for Understanding Hominoid Evolution,” Evolutionary An-
thropology 18 no. 3 (May/June 2009): 103-19.
33 Even today, unlike monkeys R. W. Wrangham and P. G. Waterman, “Condensed Tannins in
Fruits Eaten by Chimpanzees in Gombe National Park, Tanzania,” Biotropica 15 no. 3 (1983):
217-22; R. W. Wrangham et al., “The Significance of Fibrous Foods for Kibale Forest Chimpan-
zees,” Philosophical Transactions of the Royal Society of London 334 no. 1270 (November 1991):
171-78.
33 Those who survive The theory that the disappearance of forests and the drying of much of the
African continent was an important factor in the evolution of apes is under continuous evaluation.
Current scientific drilling projects (which take core samples from ancient lakebeds and examine
the pollen content and composition of the soil during the different geologic periods) aim to chart
the environmental changes over millions of years of human evolution. See Andrew Cohen et al.,
“Understanding Paleoclimate and Human Evolution Through the Hominin Sites and Paleolakes
Drilling Project,” Scientific Drilling 8 (2009): 60-65, doi:10.2204.
33 Of the great apes Justin R. Ahrens, “The Orangutan: 'Person of the Forest,'” BioWeb, April
2008, http://bioweb.uwlax.edu/bio203/s2008/ahrens_just/adaptation.htm .
33 and on the ground

Frans de Waal, Bonobo: The Forgotten Ape , 51; Takayoshi Kano, The Last

Ape , 7-8.
34 The practice may have led “It has been proffered that a major leap forward in the cognitive
evolution of hominoids may first have occurred in the building of nests, and a second major step
may have been the full transition to ground sleep. These two changes may have begun a modi-
fication of the quality and quantity of hominid sleep, which in turn may have enhanced waking
survival skills through priming, promoted creativity and innovation, and aided the consolidation
of procedural memories. Current dream research with children, adults, animals and the dreams of
modern hunter-gatherers, appears to support the hypothesis that these changes in sleep may have