Are Human Beings Apes, or Are Apes People Too?
Russell H. Tuttle
Professor of Anthropology, and in the Committee on Evolutionary Biology, the Morris
Fishbein Center for the History of Biology and Medicine, and the College of the University
of Chicago
Author's Address:
Professor Russell H. Tuttle
Department of Anthropology
The University of Chicago
1126 E. 59th Street
Chicago, IL 60637-1614 USA
e-mail Address: r-tuttle@uchicago.edu
Telephone: 773-702-7719
FAX: 773-702-4503
Revolutions in molecular
genetics and comparative cognitive psychology have led a growing cohort of scientists,
humanists, and lay animal rights activists to refer to human beings as other apes and to
subsume the Pongidae (Pan troglodytes, Pan paniscus, Gorilla gorilla and Pongo
pygmaeus) and sometimes also the Hylobatidae (Hylobates
spp.) in the Linnaean family, Hominidae (Begun 1999; Goodman et al. 1998). Without
denying the propinquity of apes and humans and the urgent need for improved humane
treatment and appreciation of all of them, I argue that human beings are not apes, nor are
apes human beings, as people are recognized to be by anthropologists.
Although captive apes may participate with humans in artifactual
cultures at the level of young children (Savage-Rumbaugh et al. 1998; Fouts and Mills
1997; Miles 1999; Patterson and Cohn 1994), they have not been found naturalistically to
possess culture: symbolically-mediated behavior, values, beliefs and ideas (White and
Dillingham 1973; Geertz 1973; Kuper 1999).
The bipedal adaptive complex serves as a paleontolologial marker that
distinguishes human beings and their Pliocene-Pleistocene ancestors and collaterals
-Hominidae- from the severally brachiating, arboreal climbing and knuckle-walking
Hylobatidae, Pongidae and Panidae.
We do not know how many genes mark levels of separation among apes and
people; we cannot discretely recognize their expression phenotypically; and, they probably
are not of equal value to sort apes from people and apes from other apes. Until the
developmental and functional biology of our genomes are much better understood (Naylor and
Brown 1998; Hamdi et al. 1999), I recommend a measure of dispassionate conservatism among
colleagues who would resolve puzzles regarding our bushy phylogeny and the largely
uncharted lineages of extant apes.
The current inclusion of at least 16 Plio-Pleistocene species with Homo
sapiens in a common higher taxon argues for Hominidae sensu stricto, with Pongo
pygmaeus, Gorilla gorilla, Pan troglodytes, Pan paniscus and the 11 species of Hylobates
relegated to other families. Therefore, I recommend that the Hominidae comprise the genera
Homo, Australopithecus, Paranthropus, Praeanthropus (Strait et al. 1997) and
provisionally Ardipithecus and that Pan, Gorilla and their Miocene-Pleistocene
ancestors comprise the Panidae. Pongidae would include only Pongo pygmaeus among
extant apes plus fossil species that are closely related to them; and the 11 species of Hylotates
and their ancestors constitute the Hylobatidae.
I endorse Wood and Collard's (1999) emphasis on postcranial morphlogy
in hominoid systematics. There never has been and probably never will be sufficient
evidence to ascribe or to deny speech or a gestural form of language for any fossil
hominid species from relatively intact, let alone crushed, skulls and natural endocasts,
since features related to language are not indelibly impressed on the surface of the human
brain. Nor can one discount language capacity in fossil hominids based on bones bounding
the vocal tract (Tuttle in press).
Apes and many monkeys are dextrous enough to make and to use the simple
stone artifacts that begin to appear in the archaeological record at 2.5 Ma; therefore,
the hand bones of late Pliocene-Early Pleistocene Hominidae are not secure guides to which
species were tool whizzes (Tuttle 1967). Indeed, it is possible that tool behavior,
largely employing vegetal and other natural objects was part and parcel of hominid
foraging and defensive behaviors for hundreds of millennia before some species began to
modify stone and bone for special tasks.
Within the Hominidae sensu stricto, several subfamilies may be
identified partly according to the extent to which they exhibit anatomical features that
suggest full commitment to terrestrial niches via bipedal adaptive complexes versus
continued reliance on arboreal climbing. Complexes of craniodental features may further
warrant grouping some species into subfamilies.
Analyses by Strait et al. (1997) indicate that the three species of Paranthropus
comprise a monophyletic group: the Paranthropinae. Currently, of the five species of Australopithecus,
only Australopithecus africanus is securely placed in the Australopithecinae;
cladistic analyses have not comprehensively included specimens of Australopithecus
bahrelghazali, Australopithecus garhi, Australopithecus anamensis, Ardipithecus ramidus
or the Turkwel hominids.
A more comprehensive cladistic analysis than that conducted by Strait
et al. (1997), particularly one that includes a rich complement of postcranial traits,
might bring Praeanthropus and perhaps Ardipithecus into the
Australopithecinae.
A collateral consequence of removing the oft-cited craniodental and
handy features as chief criteria for Homo, is that we are freer to postulate the
development and occurrence of language and stone tool-using among any or all
Plio-Pleistocene hominid genera and species. Moreover, it easier to imagine that extant
apes, particularly chimpanzees, excel some Plio-Pleistocene hominid species in tool
behaviors and perhaps in intraspecific communication.
Advocates of chimpanzee culture emphasize social or observational
learning and imitation of behaviors that become demic traditions in particular groups
(Whiten et al. 1999). The cited examples of chimpanzee culture do not include explication
of their meanings to the chimpanzees themselves. Specifically, there is no reference to
symbolic mediation or a comparable mechanism that would underpin shared values, ideas and
beliefs about their tool behavior, grooming postures, noise-making and athletic displays.
To many anthropologists, this is the sine qua non of culture (Kuper 1999), whose
development should be the focus of research by evolutionary primatologists and
anthropologists, if we are to have a cultural primatology. The challenge is to crack the
communicative codes of apes in natural habitats and noninvasively to explore the nervous
systems, vocal tracts and other anatomical structures related to vocalization and gesture
to discern whether apes naturalistically symbol even though they lack humanoid speech.
Were they to be found to symbol naturalistically, they would be symboling apes,
undoubtedly with much more to teach us about how we became people (Tuttle in press).
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--- in press. Fossils, Phylogenies and Feelings: Can Evolutionary Biology Contribute to
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