The pages：232 ~ 234
I share some of Koehle's beliefs, but not all of them. However, what is important here is that his views necessarily imply that language is not a unique and integral behavioral development but a conglomeration of skills and abilities each of which has its own ,independent phylogenetic history. Except for one aspect of language, verbal behavior is a communication and amplification of ubiqutious zoological properties. There is a suggestion here of continuity with only a few recent innovations that lifted an earlier type of communication into the realm of human language. I reject this type of continuity theory on several counts.
(1)The prerequisite skills for language can only in a few cases be shown to have a fully documented phylogenetic history that reaches up to Homo sapiens. Actually, this is the exception. Continuity theories are bolstered by citing examples from all over the animal kingdom in complete disregard for phylogenetic proximity to man. One parallel comes from birds; the next from insects; another from fishes; still another from aquatic mammals. Frequently, only one species within a given genus or family even possesses the trait, indicating clearly that we are dealing with species-specificities, probably all of comparatively recent date. The reason the examples are so disparate is that parallels are rare. This suggests accidental convergence (if, indeed, it is even that) rather than milestones within one continuous phylogeny.
(2)In addition to being unsatisfactory proof for a continuous history, the examples customarily cited might even serve as evidence of discontinuities of skills and behavior patterns because of the sporadic occurrence on the branches of the phylogenetic tree.
(3)Language is not a loose association relatively independent abilities. There is no evidence that language comes about by a gradual accretion of skills. If this were so, we should be able to see all but a few of such skills in our closest relatives should show a few less, and so on down the line of evolution. Nothing like this seems to be the case.
(4)What is thought to be the beginning of language in parrots, monkeys, or dolphins, is empirically totally different from the beginnings of language in the human infants. *At the most primitive stages of language acquisition, man does not imitate sounds, words, or sentences, but generates novel sound-sequence that are recognized as speech and language because the rules of generation bear certain formal similarities to those of the standard language. A healthy child does not ordinarily parrot (or at least no more often than at special occasions). The outstanding characteristics of language are the all-pervasive principles of productivity (see Chapter Eight). These principles are totally lacking from the examples of animal communication.
Another line of thought, different from O. Koehler's in approach but similar in theoretical structure, was contributed by Hockett (1960) and applied to animal communication by Altmann (1966) and other zoologists (see also Marler, 1961). Hockett also begins with an analysis of language in terms of what we shall call for the moment essential attributes, and then examines a great variety of animal communication systems with a view to discovering how many and which of the essential attributes of human language are discernible in the communication of other species. In contrast to Koehler, his attributes are almost entirely of a logical nature (that is. Not physiological or psychological). He calls them design features, a terminology that expresses well the intent of the investigation: it is a study of the efficiency and effect of the communication system, the result and outcome, so to speak, of behavior rather than the mechanism of the behavior itself.
I believe this approach is an innovation in biological investigations and it is apt to focus attention on many interesting aspects of communication, including the underscoring of parallel but different developments and phenotypic convergences by very different means. For instance, some of the design features that characterize language (Hockett distinguishes thirteen) are also characteristic of the so-called language of the honey bee (broadcast, rapid fading, total feedback, and perhaps specialization and discreteness), but the physical means used for the incorporation of these design features into “bee-language” are quite different from those of human language.
This is an important point. A study of design features may give us insight into some of the biases that enter into the process of natural selection, into the biological usefulness of certain features of animal communication but it is not relevant to the reconstruction of phylogenetic history. For the latter we are only interested in the relation of types of anatomical structure (including motor coordination and sensory acuity), but we disregard the usefulness or efficiency of these features to the contemporary form. Thus whatever similarities exist on the surface between dolphins and fishes, shrews and rodents, bats and birds, pandas and bears must be ignored in our attempts to reconstruct the respective phylogenies and, in fact, the more abstract and pragmatic our criteria for comparison are, the less relevant will they be to a reconstruction of phylogenetic history. For instance, among the most abstract pragmatic criteria is successful adaptation to the environment; this may be accomplished by an apparent infinity of means. If we could rank-order adaptation in terms of success, it might tell us something about life in general, but it would tell us little about phyletic descent.