Hierarchies in Biology

Sigma Xi, The Scientific Research Society

Hierarchies in BiologyAuthor(s): Marjorie GreneSource: American Scientist, Vol. 75, No. 5 (September-October 1987), pp. 504-510Published by: Sigma Xi, The Scientific Research SocietyStable URL: http://www.jstor.org/stable/27854792 .Accessed: 12/09/2013 08:17

Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp

.JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range ofcontent in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact [email protected].

.

Sigma Xi, The Scientific Research Society is collaborating with JSTOR to digitize, preserve and extend accessto American Scientist.

http://www.jstor.org

This content downloaded from 128.59.62.83 on Thu, 12 Sep 2013 08:17:46 AMAll use subject to JSTOR Terms and Conditions

http://www.jstor.org/action/showPublisher?publisherCode=sigmaxihttp://www.jstor.org/stable/27854792?origin=JSTOR-pdfhttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsp

Hierarchies in Biology

Marjorie Grene

1 hat evolution happened is a fact. Just why and how it

happened is, in part, still a matter for debate, and a number of evolutionary biologists are currently attempt ing to rethink the problem of causality in their discipline (e.g., Eldredge 1985, 1986; Gould 1982, 1986). Contem

porary Darwinism appears to restrict the search for causes to two levels only: the level of changing gene frequencies, and the level of phenotypic characters of

organisms?that is, the morphological or behavioral characters that are triggered by underlying genetic deter

minants but that nevertheless produce effects having significant consequences for the differential reproduction of the organisms in question. At the phenotypic level, in other words, individuals are differently adapted to a

given environment, and these differences result in varia tions in the number of offspring that these individuals are likely to leave in the next generation (Brandon 1981).

Sometimes, at its most reduc

tive, evolutionary theory predicates change at the genetic level only, re

garding everything else as an epiphe nomenon of relative gene frequen cies (see, for example, Williams

1985). This is an extreme form of

selfish-gene theorizing, which re

gards an organism as merely a gene's way of making more genes. Some times, on the other hand, the organ ism is the focus of attention. What organisms do, after

all, determines what genes will be handed on to their

offspring. Genes may be good at bookkeeping, but it is Father and Mother Organism that run the family busi ness. No bookkeeping, no family business. Yet it goes the other way, too: no family business, nothing to

bookkeep (Wimsatt 1980). Because Darwinian thinking moves between two levels, genes and organisms, evolu tionists have often argued that Darwinism is on principle nonreductive, or antireductive, in its import (Dob zhansky 1968; but compare Williams 1985).

From the perspective of the current debate about

evolutionary theory, however, it is Darwinism that ap pears reductive, since it limits evolutionary explanation

Marjorie Grene is Professor Emeritus of Philosophy at the University of

California, Davis. She is the editor of Dimensions of Darwinism and the

author of numerous books, including A Portrait of Aristotle, The Knower

and the Known, The Understanding of Nature, and, most recently, Descartes. In 1985 and 1986 she has been the Boeschenstein Research

Fellow at the American Museum of Natural History. Address: 206 Ridgedale Road, Ithaca, NY 14850.

Current theory seeks to account for evolution in a hierarchy of levels

that go beyond the Darwinian restriction

to the two levels of the gene and the organism

to two levels only, the gene and the organism, or, if you like, the genotype and phenotype. More inclusive units, too, some people argue, like species or ecosystems, may exercise a causal influence in the history of life. Thus a new cast of characters, bigger in both space and time than genes or organisms, has entered the evolutionary drama, and not just with bit parts, either. Vrba and

Eldredge (1984), for example, list genes, organisms, demes, species, and monophyletic taxa as entities in

volved, in different fashions, in the genealogical events that result in evolution. Eldredge and Salthe offer the same series as constituting what they call a "genealogical hierarchy." But they distinguish all these from another

nested?i.e., increasingly inclusive?set of entities, which are characterized by matter-energy exchange, and

_ which are also involved in the evolu

tionary process. These range from

organisms (in their other-than-repro ductive aspects) to populations, to

communities, to ecosystems, per haps to the whole biota (Eldredge and Salthe 1984; Salthe 1985).

In the terms introduced by Hull

(1980), these systems constitute a se ries of interactors, as distinct from

replicators. They form an ecological hierarchy, distinct from the genea logical, or informational, series. An

example of an entity somewhere be tween an organism and a population in such a sequence

would be groups that participate in what Gordon (in press) calls the "daily round" of a harvester ant colony. Groups of worker ants carry on a number of activities, such as foraging, nest maintenance, and patrolling, that

manifest characteristic temporal and spatial patterns (see

Fig. 1). Relations between worker groups develop as the

colony matures over several years, even though the individual workers live only one year. It is clear therefore that the patterns of the daily round express economic

phenomena occurring at a level larger than that of the

single ant. More-than-individual patterns seem to matter in the life of this species. In general, an expanded ontology, which allows consideration of real patterns at a number of levels, could produce a search for, and

discovery of, causes in quarters where classical evolu tionists would not have thought to seek them.

In such an expansion of evolutionary theory, the term hierarchy plays a conspicuous part. It is chiefly that

concept and its role or roles in biology that I want to examine here, and I shall return only briefly in conclu sion to the causal context.

504 American Scientist, Volume 75


http://www.jstor.org/page/info/about/policies/terms.jsp

Concepts of hierarchy The discussion of hierarchy, Gould (1986) remarks in his

Sigma Xi centennial essay in American Scientist, "has

raged for ten years and continues unabated." But the same debate has been simmering, or boiling up recur

rently, and in rather different places, for a good deal

longer. In fact, one can trace the term hierarchy in use in what seems to be a variety of meanings back to the

beginning of the century. I hope that a look at the history of this usage will show the significance that current work in hierarchy theory has for biological research and, more

generally, for our understanding of nature. The term hierarchy occurs in biological discourse in

what appears at first sight a bewildering number of senses. Ethologists have their social hierarchies, or peck ing orders, where the alpha animal bosses beta, beta bosses gamma, and so on down to the unfortunates at the bottom of the heap. Taxonomists have their hierar chies, which serve to place small groups in larger ones,

species in genera, genera in families, and so on. Physiol ogists and animal behaviorists may speak of levels of

organization hierarchically related to one another. Em

bryologists observe hierarchies of forms and functions: cells organized into tissues, tissues into organs. The same word keeps turning up, but with many meanings.

When one looks back at the contexts in which the

concept has chiefly occurred, however, one finds that it is two different senses of the term that have played important theoretical roles. On the one hand, there are

hierarchically organized systems that consist of smaller units contained in larger ones, in such a way that the lower level units provide material for the arrangements at upper levels and the upper level arrangements con

strain and thus control the activities of the lower levels. What one is interested in here is levels of organization, the dynamics as well as the structure of hierarchical

systems. Whether those systems be social, anatomical or

physiological, they are, as Polanyi (1968) put it, systems of dual control. In an army, the lower ranks obey the

upper, yet the upper ranks would not be ranks at all unless the troops were there to follow orders. It is the flow of information, horizontally as well as vertically, that constitutes such a system as the kind of entity it is.

Organisms or systems of organisms seem to be arranged in analogous fashion. The genome is contained in the nucleus, the nucleus in the cell, the cell in a tissue, the tissue in an organ, and so on to the whole complex that is the organism. And again, it is the flow of information both horizontally and vertically that makes the organism an integrated, working whole. This kind of hierarchy, in which information flows between levels in both direc tions, as well as between units within a given level, we

may call a hierarchy of control. There are also hierarchies in which smaller aggre

gates of like entities are placed in larger groups, as

species in genera, genera in families, and so forth, but where the element of control is lacking. There is no

dynamic involved, nor does information run in both directions. Here we have hierarchies, not of control, but of classification. True, we may think in a sense of any higher level as, so to speak, controlling the lower levels; it certainly limits them. A bat's wing, a bird's wing, a

whale's flipper, a lizard's leg: all are variants of the vertebrate pentadactyl limb, which is, in this sense, a container for all the others. But it doesn't work the other

way: the particular limbs don't somehow cooperate to

produce the pentadactyl limb. What control there is here

Figure 1. A group of harvester ants (Pogonomyrmex barbatus) works together to remove a twig that had been blocking the entrance to the

colony's nest. This group is an example of an entity that falls somewhere on an ecological hierarchy between an organism and a population; such groups are an integral part of the functioning of the colony over the several years of its existence, even though individual ants live only one year. (Photograph by Raymond Mendez.)

1987 September-October 505



consists in an identity of structure, which defines the

possibilities for limb formation. But it is not dynamic, and it is unidirectional, not dual. The meaning of

hierarchy in systematics, therefore, seems to differ fun

damentally from its meaning in discussions of hierarchi cal systems organized at more than one level.

Given these two senses of hierarchy, we can look back at the history of the term in biology and see how the two senses have developed and interacted, if not

coalesced, in a series of changing contexts.

Hierarchies of control Control hierarchies have been conspicuous recurrently in a number of biological debates. The old mechanism vitalism controversy raised the question of whether

biological systems need to be described or explained in terms more complex than those of physics. In 1930, for

example, Ewald Oldekop published a book, On the Hierarchical Principle in Nature and Its Relations to the Mechanism-Vitalism Problem, arguing that if living sys tems are organized on more than one level, there must be some "vitar principle, over and above the mechanis tic-materialistic laws of physics, to explain their unique character. This notion was in turn embedded in meta

physical conceptions of a hierarchically organized uni verse, in philosophies of emergence (i.e., where novel,

unpredictable entities, such as consciousness, make their

appearance at higher levels); the emphasis in these

systems of thought was on degrees of reality (Ungerer 1966). Nor was such thinking confined to out-and-out vitalists or emergence metaphysicians. Woodger (1929), for example, talked in his Biological Principles about the hierarchical organization of life, certainly not in any vitalistic sense. As the Belgian embryologist Dalcq (1951)

cat mouse

Figure 2. Each branch point in this cladogram for five kinds of vertebrates is defined by one or more characteristics that are shared

by the higher levels of the cladogram and that are interpreted as

evolutionary novelties. A cladogram thus combines a hierarchy of classification with an implied evolutionary hierarchy. (After

Eldredge and Cracraft 1980.)

put it, life is matter, only organized differently. In

general, it was resistance to the then regnant form of mechanistic reductionism that triggered the discussion of hierarchy in the thirties.

A similar debate, although couched in very different terms, developed in the sixties and early seventies. This time it was the biochemical revolution that fired the

imaginations both of reductionists and of those who resisted them. The former were sure of their triumph: once the dna code had been cracked, clearly biology had been reduced to physics and chemistry. There were the two strands of dna, with its punctuated triplet code,

producing the twenty amino acids that are the building blocks of every organism, from E. coli to Einstein. What more could one ask?

On the other hand, it was just as plain to nonreduc tionists that life had not been reduced to physics and

chemistry?far from it. It's not just the organic bases of the dna strands that do the work: it's the way they are

arranged that makes them carriers of information. Life

The term hierarchy occurs in biological discourse in what appears at first sight a

bewildering number of senses

depends not simply on macromolecules but on the

ordering of those molecules in such a way that they form a code or messages?information. Of course this is not

vitalism; no mysterious something comes from afar to add itself to "merely" physical materials. Again, as Dalcq had said, life is matter, only organized differently. Suppose, for example, you had a cassette tape of a piece of music. You ask a physicist to examine this object thoroughly and tell you all about it. The physicist may provide you with a detailed description of the variations in the magnetic charges on the tape but could never tell

you, strictly in terms of physics, that this is a tape of the Beethoven Third Piano Concerto. Physics alone conveys no meaning, no utterance. Systems that convey mes

sages, in contrast, are necessarily hierarchical, in that the

arrangement of their elements constrains, and thus controls, the behavior of those very elements as long as the system so constituted continues to exist. The ele

ments provide the material, or the initial conditions, for the system's operation; the ordering of the elements furnishes boundary conditions that limit the behavior of those elements, while enabling the system as a whole to

carry out functions that its elements, outside that order

ing, could never have performed. Foundational for much of this work was Simon's

famous 1962 paper "Architecture of Complexity," in which he argued that hierarchical arrangement is a

necessary condition for the initiation and maintenance of

complex systems. In his story of the two watchmakers, inefficient Tempus tried to put the thousand pieces of a

watch together piece by piece and had to start over after

every interruption. Efficient Hora neatly arranged her

pieces into units of ten, and the tens into hundreds, so that when the phone rang she always knew just where she had stopped. Hora turned out plenty of working

watches; Tempus did not.




Figure 3. Although the species in the Alcelaphini group of antelopes (wildebeests and similar species) are far more diverse in number and

morphology than the Aepycerotini (impalas), the abundance of the two groups appears roughly equal according to modern census data, and

the Aepycerotini have endured far longer. The relative diversity and abundance of the two groups is easier to explain in terms of evolution

acting on whole species than in strict Darwinian terms of evolution acting only on genes and organisms. Specifically, Elisabeth Vrba argues that largely because the Alcelaphini are much more specialized in their adaptations to specific environments than are the Aepycerotini, they have a higher rate of speciation and extinction and thus a greater diversity and divergence in morphology. (After Vrba 1984.)

Although Simon had no primary interest in biology as such, his argument was enthusiastically adopted, and

adapted, by participants in the reductionism debate. The

blossoming of information theory contributed as well. It seemed for a time that "information" would transform

biology, or had already done so (Johnson 1970). And I'm not sure that electron microscopy did not reinforce the antireductionist mood by exhibiting structure and orga nization, not just chemistry, at increasingly minute levels, much as the first microscope had done in the seventeenth century. Whatever its sources, the upshot of all this discussion is well exemplified in the volume on

hierarchy theory edited by Pattee (1973). In a series of

essays by Simon, Levins, Grobstein, and others, the case is made that life must be studied on at least two levels, not one alone. Again, it was the problem of reductionism that was being addressed, not specifically in evolution

ary theory, but in the biological sciences as a whole.

Control hierarchies and systematic hierarchies

Independently of these discussions, the term hierarchy had come into use in systematics around 1900. "Linnae an hierarchy" is our expression for a system of nomen clature which Linnaeus himself apparently just called an order or a system, not a hierarchy. Although Lamarck

did caution his readers not to forget "the beautiful

hierarchy due to Linnaeus," the term seems to appear regularly in taxonomic usage only in the present century (Lamarck 1809; cf. Whyte 1973). Both Spencer and

Darwin clearly thought of the systematic arrangement of

organisms in what would now be called hierarchical terms, like nests of Chinese boxes. But neither one

appears to have used the word in the context of system atics (Spencer 1862; Barrett et al. 1980, 1981). The earliest use I have found is in an essay on classification, not by a

taxonomist, but by the French sociologists D?rkheim and Mauss (1901-02).

Has this taxonomic usage interacted with the antire ductionist debates of the thirties and sixties to usher in an expansion of evolutionary causality? We have had control hierarchies, in terms of emergence (in the thir

ties) and of information (in the sixties). We have had, and still have, hierarchies of classification in taxonomy. But now we have a new debate in which, as against the two levels of Darwinian explanation, an expansion of

evolutionary biology into a larger number of hierarchical levels is called for. Is there a historical, and even a

conceptual, connection between these three: the old antireductionist hierarchies, the concept of hierarchy in

systematics, and the present advocacy of the notion of an evolutionary hierarchy (or hierarchies)? On the face of it, evolutionary hierarchies form a subclass of control




hierarchies. Is the notion of taxonomic hierarchy just out there in left field, or is there some connection between the use of the word hierarchy in systematics and, in the current literature, in evolutionary theory?

I believe there is such a connection, and that it has a

definite, if indirect historical source: Hennig's Phylogenet ic Systematics, published in German in 1950 and in a more elaborate English-language version in 1966. Although Hennig's work was not concerned in any way with the

That evolution happened is a fact, fust why and how it happened is, in part, still a matter for debate

problem of reductionism, what it did was to place the taxonomic use of the term hierarchy firmly in the context of evolution. His aim was to oppose the idealistic

morphology characteristic of German taxonomy in his time. Idealistic systems may cluster natural groups in

any number of aesthetically satisfying, but not otherwise well-founded ways. Hennig was defending the hierar chical view of classification against these competitors by demonstrating that the hierarchy of classification is the

proof of the fact of evolution. That argument, of course, like almost anything connected with either evolution or

systematics, is already to be found in Darwin, even

though the term hierarchy does not occur in his work.

Hennig refers in this context to a work by Tschulok

(1922), in which, although the term hierarchy is not

used, the claim that "the natural system is the proof of the doctrine of descent" is heavily emphasized.

In the application of his hierarchical system, Hennig initiated the construction of what have come to be called

cladograms, branching diagrams, such as the one shown in Figure 2, in which organisms are ordered according to nested sets of evolutionary novelties (Eldredge and Cracraft 1980; Cracraft 1983; for similar diagrams in Darwin's notebooks, see Gould 1986). Hennig's proce dure corresponded pretty closely to the formal analysis of hierarchies published by Woodger (1952) and applied to taxonomy by Gregg (1954), and he drew heavily on both these sources in the revised version of his book. The point here is that such hierarchies of ordered

evolutionary novelties represent at one and the same time both the series of natural groups divided from one another by uniquely derived characters and the course of evolution. This method in taxonomy thus confirms the doctrine of descent with modification, and, in a comple mentary (not a vicious!) circle, the fact of descent ex

plains the very existence of such a system. Thus we have the classificatory hierarchies and phylogeny brought firmly together. Moreover?and I think this is important for the current discussions of hierarchy theory?clado grams exhibit species as units, which can be seen, each in its discrete place, in an evolutionary pattern, so that

species or even higher monophyletic taxa can be thought of as definite historical entities playing a role in the

evolutionary process. Lineages, chunks of a genealogical nexus, can count as real, just as genes or organisms do.

Much recent work on speciation theory relies on this

new perspective, which counts units above the level of the organism as real historical entities. A case in point, illustrated in Figure 3, is the work by Vrba (1984) on

antelope species, both fossil and living: she contrasts the relative longevity of impala species, which are adapted to a relatively wide variety of environments, with the

wildebeests and other closely related species, which are more specialized in their adaptations to specific environ ments, and she assesses a number of models that could account for this difference. If her "effect hypothesis" is correct, the greater longevity of impala species may result, not from a mechanism of species selection, but

simply from the structure and physiology of the general ists as against their specialist sisters. Yet such a debate, about the alternative of species selection as against effect evolution, can occur only in a context in which not only genes and organisms, but species as well, are taken

seriously as historical entities, and hence as possible causal forces.

This brings us back to the question of causality, from which we started. Let us look, in conclusion, at three aspects of current thinking on hierarchies in rela tion to the search for causes: its origins, its differences from the hierarchy theory of fifteen years ago, and its

promise for the future.

Current hierarchy theory One starting point of current thinking I have suggested was the tradition of cladistic analysis initiated by Hen

nig, which encouraged attention to species, and in

general to monophyletic taxa, as real entities. Perhaps more global in its influence, further, is the debate about units of selection (Wimsatt 1980; Brandon and Burian

1984). Lewontin's (1970) now-classic paper on the units of selection demonstrated that three conditions are both

necessary and sufficient to produce natural selection; selection requires slight phenotypic variations in a popu lation of organisms, differential fitness (in the sense that some organisms will probably leave more descendants than others), and heredity (in particular, inheritance of differential fitness). His argument leaves open, however, the possibility that selection could occur at any level, including genes, organisms, demes, and species. The

process is not as such limited to a given level. Debate on this matter does indeed continue unabated. Vrba's ante

lope work clearly fits in here. Another factor in generating current hierarchy

thinking was the theory of punctuated equilibrium (El dredge and Gould 1972). The pattern of evolution, it was

argued, is not one of constant flux; many species persist in relative stability throughout the long stretch of their existence, occasionally giving rise in relatively short bursts to daughter species. Thus each species, while it exists, appears to the paleontologist to be one coherent historical entity. Punctuated equilibrium, like cladistic

analysis, looks at species, in this case backward through time, and so goes beyond the restriction of evolutionary explanation to genes and organisms.

Related to punctuated equilibrium was (and still is) the move to separate macro- from microevolution. Strict

Darwinism still insists that the forces of microevolution can be extrapolated to explain all evolutionary phenome




na (Bock 1986). Macroevolutionists are open to a plurali ty of explanatory principles at a plurality of hierarchical levels.

By now there are also some alternative models of evolution in the field; for example, there are theories that

emphasize form, rather than only the relative adapted ness of particular variants, as causal (Kemp 1985). An other problem that leads into considerations of hierarchy is whether patterns of individual development exercise causal power (Maynard Smith et al. 1985; Thomson 1985; see also Keith Thomson's article on pp. 518-20 of this

issue). The aforementioned case of the pentadactyl limb illustrates both these problem areas. Should the histori

cally given forms of the vertebrate limb be counted as

part of the causality of the evolutionary process? And should inherited patterns of limb development be count ed as causes or only as constraints (i.e., limiting condi tions) when one thinks about the sequence of contingen cies that sum up to evolution?

Although the current writers on hierarchy theory still cite the literature from the sixties, their theory displays some striking novelties. The earlier analysis emphasized what I have called (following Polanyi 1968) dual control. Pattee's (1973) definitions of hierarchy, which were canonical for this period, always dealt with two levels. The dna code was the prime example: there

were the four bases, and then there was the arrange ment (triplets with punctuation) that made them a code.

Hierarchy theory currently shows a different physi ognomy in two respects. Current theorists build their hierarchies in a series of levels, displaying the transitivity that is supposed to be diagnostic for hierarchies in

general: they build nests of Chinese boxes. (A transitive relation is such that if A has the relation r to B, and B to C, then A has the relation r to C, and so on for D, ?, etc.) On the face of it, Pattee's hierarchies, consisting of two levels rather than a series, lacked this seemingly essen tial ingredient.

In discussions of causality, which is what interests us here, the new hierarchy theorists deal, not in pairs of levels, but in threes?a focal level, a lower level, and a

higher one. For example, if the organism in its reproduc tive aspect is the focal level, then the lower level would be the genes (or the genome), which provide initial conditions for the organism's reproducing itself, and the

higher level would be the deme, which limits the activities of its constituent organisms, providing bound

ary conditions. Sometimes there may be effects from more remote levels. Obviously, for example, if a species is wiped out, everything at lower levels goes with it. But it is in terms of three levels that we typically look for causal relations. They operate, within those limits, both

up and down, and of course sideways: each level has its own dynamic.

In some versions of this new biological ontology, moreover, a sharp distinction is made, as I pointed out

earlier, between two major evolutionary hierarchies. There are the genealogical and the ecological hierarchies. The one has to do with reproduction, via the transfer of information, and the other with interaction, or the economics of transactions in, with, and of organisms. Not all hierarchy theorists make this distinction, but it is here, I want to suggest, that hierarchy theory holds most

promise for research programs in evolutionary theory. Darwinism is a two-step, externalist theory. There must be variations, which reproduce selectively and in persis tent new ways?but such selective persistence will occur if and only if the environment is such as to make the new features relatively more adaptive and the older ones less so. Adaptedness is relative to a given environment; if the needed variations are available, the environment will

probably trigger evolutionary change. But only the rela

It is the flow of information both horizontally and vertically that makes the

organism an integrated, working whole

tion of available variations to a given environment can

produce the proliferation of novel features that issues in evolution. Yet environment, though central to Darwin ian thinking, has not had a definite working place within classical evolutionary theory (Kimler 1983). Organisms themselves, though the agents, or targets, of selection, have usually been taken purely as replicators?vehicles of reproduction. Their broader environment-related ac tivities have been interpreted purely as means to repro duction.

Twentieth-century Darwinism prides itself on "pop ulation" thinking. Is a population chiefly a unit of

reproduction? Surely a population is an aggregate of

conspecifics interacting in a variety of ways with one

another, and in turn forming part of a community of

populations of different species, which in turn forms part of an ecosystem, and so on. Of course community structure has an influence, not only on population structure, but on the reproduction of demes, organisms, genes, and vice versa: who breeds with whom deter mines who (in the next generation) constitutes the

population or community. It is important to separate out the strictly reproductive from the economic in order to

distinguish causal relations between the two hierarchies as well as within each one; this seems to be a move of

conceptual clarification that could cash out in the future in significant empirical work. All evolution must occur

through the interaction of the economic with the genea logical hierarchy. It is the investigation of such causal relations that current hierarchy theory should help to initiate.

References Barrett, P. H., D. J. Weinshank, and T. T. Gottlebar. 1980. Concordance

to Charles Darwin's Transmutation and Metaphysics Notebooks. Michigan State Univ. Press.

-. 1981. A Concordance to Darwins Origin of the Species, First Edition. Cornell Univ. Press.

Bock, W. J. 1986. Species concepts, speciation, and macroevolution. In Modern Aspects of Species, ed. K. Iwatsuki et al., pp. 31-57. Univ. of

Tokyo Press.

Brandon, R. N. 1981. A structural description of evolutionary theory. PSA 1980 2:427-39.

Brandon, R. N., and R. Burian, eds. 1984. Genes, Organisms, Popula tions. Cambridge, Mass.: Bradford Books.




Cracraft, J. 1983. Cladistic analysis and vicariance biogeography. Am.

Sei. 71:273-81.

Dalcq, A. M. 1951. Le probl?me de l'?volution est-il pr?s d'?tre r?solu?

Annales de la Soci?t? Zoologique de Belgique 82:118-38.

Dobzhansky, T. 1968. On Cartesian and Darwinian aspects of biology. Grad. J. 8:99-117.

D?rkheim, E., and M. Mauss. 1901-02. De quelques formes primitives de classification. L Ann?e Sociologique 6:1-72.

Eldredge, N. 1985. Unfinished Synthesis. Oxford Univ. Press.

-. 1986. Economies, information, and evolution. Ann. Rev. Ecol.

Syst. 17:351-69.

Eldredge, N., and J. Cracraft. 1980. Phylogenese Patterns and the

Evolutionary Process. Columbia Univ. Press.

Eldredge, N., and S. J. Gould. 1972. Punctuated equilibria: An

alternative to phyletic gradualism. In Models in Paleobiologi/, ed. T. J.

Schopf, pp. 82-115. San Francisco: Freeman, Cooper, and Co.

Eldredge, N., and S. N. Salthe. 1984. Hierarchy and evolution. In

Oxford Surveys of Evolutionary Biology, ed. R. Dawkins and M. Ridley, pp. 184-208. Oxford Univ. Press.

*

Gordon, D. In press. The dynamics of group behavior. In Perspectives in

Ethology, vol. 7, ed. P. Bateson and P. Klopfer.

Gould, S. J. 1982. Darwinism and the expansion of evolutionary

theory. Science 216:380-87.

-. 1986. Evolution and the triumph of homology, or why history matters. Am. Sei. 74:60-69.

Gregg, J. 1954. The Language of Taxonomy. Columbia Univ. Press.

Hennig, W. 1950. Grundz?ge einer Theorie der phylogenetischen Systematik. Berlin: Deutscher Zentralblatt.

-. 1966. Phylogenetic Systematics. Univ. of Illinois Press.

Hull, D. 1980. Individuality and selection. Ann. Rev. Ecol. Syst. 11:311 22.

Johnson, H. A. 1970. Information theory in biology after eighteen years. Science 168:1545-50.

T. S. Kemp. 1985. Models of diversity and phylogenetic reconstruction. In Oxford Surveys of Evolutionary Biology, ed. R. Dawkins and M.

Ridley, pp. 135-58. Oxford Univ. Press.

Kimler, W. C. 1983. Mimicry: Views of naturalists and ecologists before the modern synthesis. In Dimensions of Darwinism, ed. M. Grene, pp. 99-127. Cambridge Univ. Press.

Lamarck, J.-B. 1809. Philosophie Zoologique. Part One.

Lewontin, R. C. 1970. The units of selection. Ann. Rev. Ecol. Syst. 1:1 18.

Maynard Smith, ]., et al. 1985. Developmental constraints and evolu tion. Quart. Rev. Biol. 60:265-87.

Oldekop, E. 1930. ?ber das hierarchische Prinzip in der Natur und seine

Beziehungen zum Mechanismus-Vitalismus Problem. Reval: Wasserman.

Pattee, H. H., ed. 1973. Hierarchy Theory. New York: Braziller.

Polanyi, M. 1968. Life's irreducible structure. Science 160:1308-12.

Salthe, S. N. 1985. Evolving Hierarchical Systems. Columbia Univ. Press.

Simon, H. 1962. The architecture of complexity. Proc. Am. Phil. Soc. 106:462-82.

Spencer, H. 1862. A System of Synthetic Philosophy, vol. 1. London: Williams and Norgate.

Thomson, K. S. 1985. Essay review: The relationship between develop ment and evolution. In Oxford Surveys of Evolutionary Biology, ed. R. Dawkins and M. Ridley, pp. 220-33. Oxford Univ. Press.

Tschulok, S. 1922. Deszendenzlehre. Jena: G. Fischer.

Ungerer, E. 1966. Die Wissenschaft vom Leben. Freiburg and Munich: K. Alber.

Vrba, E. 1984. Evolutionary pattern and process in the sister-group Alcelaphini-Aepycerotini (Mammalia: Bovidae). In Living Fossils, ed. N. Eldredge and S. Stanley, pp. 62-79. Springer Verlag.

Vrba, E., and N. Eldredge. 1984. Individuals, hierarchies, and process es: Towards a more complete evolutionary theory. Paleobiology 10:146-71.

Whyte, L. L. 1973. The structural hierarchy in organisms. In Unity through Diversity, ed. W. Gray and N. D. Rizzo, pp. 271-85. New

York: Gordon and Beach.

Williams, G. C. 1985. A defense of reductionism in evolutionary biology. In Oxford Surveys of Evolutionary Biology, ed. R. Dawkins and M. Ridley, pp. 1-27. Oxford Univ. Press.

Wimsatt, W. C. 1980. Reductionistic research strategies and their biases in the units of selection controversy. In Scientific Discoveries: Case

Studies, ed. T. Nickles, pp. 213-59. Reidel.

Woodger, J. H. 1929. Biological Principles. London: Routledge and

Kegan Paul.

-. 1952. From biology to mathematics. Brit. ]. Phil. Sei. 3:1-21.

F B <

8).,1NM+S

14

t BYT IT..TT2......



Article Contentsp. 504p. 505p. 506p. 507p. 508p. 509p. [510]

Issue Table of ContentsAmerican Scientist, Vol. 75, No. 5 (September-October 1987), pp. 456-560Front MatterLetters to the Editors [pp. 456-459]Erratum: The Science of Computing: Computer Models of AIDS Epidemiology [pp. 459-459]Sigma Xi News [pp. 460-461]The Science of Computing: Baffling Big Brother [pp. 464-466]The Origin of the Moon [pp. 468-477]The Evolution of Early Land Plants [pp. 478-489]Making a Quark Plasma [pp. 490-496]Remembering Odors and Their Names [pp. 497-503]Hierarchies in Biology [pp. 504-510]Views: What is the national agenda for science, and how did it come about? [pp. 511-517]Marginalia: History, Development, and the Vertebrate Limb [pp. 518-520]The Scientists' BookshelfReview: untitled [pp. 521-522]Review: untitled [pp. 522-522]Review: untitled [pp. 522-524]Review: untitled [pp. 524-524]Review: untitled [pp. 524-525]Physical SciencesReview: untitled [pp. 525-525]Review: untitled [pp. 525-525]Review: untitled [pp. 525-525]Review: untitled [pp. 525-526]Review: untitled [pp. 526-526]Review: untitled [pp. 526-526]Review: untitled [pp. 526, 528]Review: untitled [pp. 528-528]Review: untitled [pp. 528-528]Review: untitled [pp. 528-528]Review: untitled [pp. 528-529]Review: untitled [pp. 529-529]Review: untitled [pp. 529-530]Review: untitled [pp. 530-530]Review: untitled [pp. 530-530]Review: untitled [pp. 530-531]Review: untitled [pp. 531-531]

Earth SciencesReview: untitled [pp. 531-531]Review: untitled [pp. 531-531]Review: untitled [pp. 531-532]Review: untitled [pp. 532-532]Review: untitled [pp. 532-532]

Life SciencesReview: untitled [pp. 532-533]Review: untitled [pp. 533-533]Review: untitled [pp. 533-534]Review: untitled [pp. 534-534]Review: untitled [pp. 534-534]Review: untitled [pp. 534-535]Review: untitled [pp. 535-535]Review: untitled [pp. 535-535]Review: untitled [pp. 535-535]Review: untitled [pp. 535-536]Review: untitled [pp. 536-536]Review: untitled [pp. 536-536]Review: untitled [pp. 536-537]Review: untitled [pp. 537-537]Review: untitled [pp. 537-537]Review: untitled [pp. 537-538]Review: untitled [pp. 538-538]Review: untitled [pp. 538-538]Review: untitled [pp. 538-539]Review: untitled [pp. 539-539]Review: untitled [pp. 539-539]Review: untitled [pp. 539-540]Review: untitled [pp. 540-540]Review: untitled [pp. 540-540]Review: untitled [pp. 540-541]Review: untitled [pp. 541-541]Review: untitled [pp. 541-542]Review: untitled [pp. 542-542]Review: untitled [pp. 542-542]Review: untitled [pp. 542-542]Review: untitled [pp. 542-542]Review: untitled [pp. 542-543]Review: untitled [pp. 543-543]Erratum: Guide to Fossil Man, 4th ed. [pp. 543-543]

Behavioral SciencesReview: untitled [pp. 543-543]Review: untitled [pp. 543-544]Review: untitled [pp. 544-544]Review: untitled [pp. 544-545]Review: untitled [pp. 545-545]Review: untitled [pp. 545-546]Review: untitled [pp. 546-546]

Mathematics and Computer ScienceReview: untitled [pp. 546-546]Review: untitled [pp. 546-546]Review: untitled [pp. 546-547]Review: untitled [pp. 547-547]Review: untitled [pp. 547-547]Review: untitled [pp. 547-547]Review: untitled [pp. 547-548]

Engineering and Applied SciencesReview: untitled [pp. 548-548]Review: untitled [pp. 548-548]Review: untitled [pp. 548-548]Review: untitled [pp. 548-549]

History and Philosophy of ScienceReview: untitled [pp. 549-549]Review: untitled [pp. 549-549]Review: untitled [pp. 550-550]

Books Received [pp. 550-556]A New Agenda for Science: Scientists and the Public [pp. 558, 560]Back Matter

Hierarchies in Biology

Documents

Transcript of Hierarchies in Biology