178 PART TWO: FUNDAMENTAL PATTERNS OF MEANING10. The process of classifying natural objects is part of the de- scriptive task of any science.11. Meaning in the life sciences consists primarily in theoretical un- derstanding of how the various orders of living things came into being.12. Biologists use the method of natural history.13. The ruling idea in natural history is the concept of evolution.14. Natural history analysis provides a useful basis for the con- struction of an intelligible hierarchy of patterns of living things.15. Structural analysis has to do with the patterns of organiza- tion of things.16. Functional analysis has to do with processes or modes of activ- ity.17. One of the central concepts of biology is organization.18. What is peculiar to biology is the kind of organization exhibited by living things.19. An “organism” is a patterned whole composed of interdependent coordinated parts.20. Living things have their own special kinds of organization.21. The characteristic functions of living things are those connect- ed with self-perpetuation, the meaning of which is the key to all biological understanding.22. Meanings in biology, as in all other sciences, are empirical, factual, descriptive, and ultimately general and theoretical in orientation. ____________________
BIOLOGY 179 ____________________ The distinctive features of biological meanings arise from the special subject matter studies, namely, living things. The unique property of living things is their power of self-perpetuation, supported by the processes of metabolism. ____________________
180 PART TWO: FUNDAMENTAL PATTERNS OF MEANING If a thing sustains its own life, then it is said to be alive. Humans, with complex systems of independent parts, use the energy from the matter around them to maintain life. The raw materials of plants and animals would suffice as they exist. How does what humans consume, and especially the way it’s prepared, say about the level of advancement as a species?
182 PART TWO: FUNDAMENTAL PATTERNS OF MEANINGAs in all science, biological descriptions are abstractions from theconcrete actuality of the things investigated. No attempt is made togive a full qualitative account of living things. Instead, certaincarefully defined aspects of these things are separated out for spe-cial attention in such a way as to render the resulting descriptionscapable of being verified by any observer. In this fashion biologyqualifies as an objective science. BIOLOGICAL INVESTIGATION IS OBSERVATION OF THE WORLD OF LIVING THINGS The obvious starting point in biological investigation is obser-vation of the world of living things. The attempt to render thatworld intelligible results in the creation of descriptive categories bywhich observed similarities and differences may be noted and livingthings assigned to specified classes. The process of classification is, ofcourse, implicit in all rational activity. As pointed out in the discus-sion of language, the symbols of discourse refer to classes of entities.For example, “run” refers to a class of actions, and “book” to aclass of objects. In mathematics, the idea of set or class was like-wise shown to lie at the basis of the subject. Similarly, the systemat-ic study of living things naturally begins with the attempt to orderand simplify the enormously variegated and confusing world of life bythe use of descriptive classifications. This process of classification isknown as “taxonomy.” THE PROCESS OF CLASSIFICATION IS KNOWN AS “TAXONOMY” The fundamental taxonomic unit in biology is the species, con-sisting of all organisms that interbreed. Similar species are groupedtogether to form a genus. Genera in turn are combined by more far-reaching similarities into families, families into orders, orders intoclasses, classes into phyla, and phyla into kingdoms (plant and ani-mal, respectively, the most general groupings). For example, humanbeings belong to the species Homo Sapiens, the genus Homo, the familyHominidae, the order Primates, the class Mammalia, the phylum Chor-data, and the kingdom Animalia. These taxonomic distinctions and oth-er intermediate levels (such as subphyla, e.g., Vertebrata, and su-perclasses, e.g., Tetrapoda) are based upon somewhat arbitraryjudgments of similarity in structure, function, and development, thatare generally agreed upon by most qualified biologists. The process of classifying natural objects is part of the de-scriptive task of any science. It is the aspect of science that is closestto common sense. By the same token, it is least prominent in those sci-ences that have achieved the highest degree of theoretical elabora-tion. For example, physics classification plays almost no part, as itdid in the early days of the science when names were assigned to dif-ferent kinds of motion. While astronomy still includes classificationof celestial bodies, the center of interest in this discipline now lies inthe general laws and principles that make the observed phenomena in-telligible. Similarly, chemistry, that was once largely a taxonomicdiscipline, arranging various material substances in kinds accordingto qualitative properties, has become a precise theoretical discipline
BIOLOGY 183using substantially the same methods and concepts as physics. Evengeology, in which the taxonomy of substances and processes consti-tuting the earth comprises a major part of the standard content ofthe field is closer in concept and procedure to the exact theoreticalmodels of physics and chemistry. THEORETICAL ANALYSIS PARTICULARLY EVIDENT IN BIOLOGY This progressive subordination of taxonomy to theoreticalanalysis is particularly evident in biology. Linnaeus, the great eigh-teenth-century Swedish botanist, developed the art of classificationof living things to a high level, establishing biology as the taxonomicdiscipline par excellence. While the student of modern biology alsomust know the kinds of living things and the names assigned to them,this ordering of types is now considered only the beginning of the sci-ence. Far from being the explanation of the world of life, it is onlythe statement of the problem that theoretically biology has to solve.In contemporary biology the refinement of common sense attained inthe description of living things by the process of classification is not ameasure of understanding in the subject. Meaning in the life sciencesconsists primarily in theoretical understanding of how the various or-ders of living things came into being. BIOLOGISTS USE THE METHOD OF NATURAL HISTORY In the search for these meanings biologists use the method ofnatural history. In this respect biological inquiry differs markedlyfrom the physical sciences. In physics and chemistry the origin and de-velopment of various kinds of physical systems is of little interest.Time enters symmetrically and on equal terms with length and mass inthe formulation of laws of motion. In biology, the temporal factorbecomes a separate and prominent consideration. Inquiry is no longerdirected primarily at the discovery of invariant relationships amongthe three metrical elements, but at the question of how each particu-lar kind of organism came to be what it is—of the causes and the pro-cesses giving rise to the manifold special patterns of life. Natural history certainly does have some relevance in physi-cal science. Physical cosmogony has to do with the origin and devel-opment of the physical world as a whole—the birth and death of starsand planets, the creation and destruction of matter, and the past andfuture of space itself. Geology also makes large use of natural his-tory in tracing the metamorphosis of the earth. But none of the physi-cal sciences is as directly and centrally concerned with natural his-tory investigation as is biology, where general laws are sought forthe sake of understanding the intrinsically interesting and puzzlingparticular forms of life. The ruling idea in natural history is the concept of evo-lution, a revolutionary idea distinguishing the thought of the pastcentury and a half from that of all earlier times. It was formerlybelieved the orders of nature were immutable and that the variouskinds of material bodies and living things had existed as such from thebeginning. In the nineteenth century it became widely recognized thatthe world is a dynamic order rather than a static one and that themyriad sorts of things, both animate and inanimate, comprising theworld exist in their present forms as a result of a process of tempo-ral development.
184 PART TWO: FUNDAMENTAL PATTERNS OF MEANING The explanatory basis for the observed and inferred phe-nomena of natural history in the world of living things is the theoryof evolution, with which the name of Charles Darwin is preeminentlyassociated. Three concepts figure prominently in this theory. the firstis that of inheritable variations. Clearly, if the kinds of livingthings change over time, variation must occur in individual organismsand be passed on to succeeding generations. These inheritable varia-tions occur either as a result of sexual recombinations or by muta-tions (chance modifications of genetic patterns). The second conceptis adaptation. Each organism lives in an environment (both physicaland organic) and interacts with it in such a way as to maintain itself.Adaptation is measured by the degree to which such self-maintenancesucceeds. The third concept is differential reproduction or naturalselection. If inheritable variations are such that an organism is fer-tile and well enough adapted to survive and prosper through the re-productive period, those variations will be confirmed, while othersthat lead to sterility or poor adaptation will not. By this process, itis believed, over long periods of time existing forms of life have comeinto being. The theory is confirmed by abundant evidence from paleon-tology (chiefly the study of fossils) concerning the forms of life thatexisted at various stages in the earth’s history. Not only does natural history explain the existence ofobserved taxonomic classes, but classifications may also be improvedby reference to developmental factors. Significant groups of organ-isms can best be made by analyzing lines of descent, indicating origins,divergences, and convergences of types. Natural history analysisprovides a useful basis for the construction of an intelligible hierar-chy of patterns of living things so organized in temporal sequence asto provide satisfying explanations for the observed similarities anddifferences in kinds of organisms. STRUCTURAL AND FUNCTIONAL ANALYSIS The methods of biological investigation are by no means ex-hausted by taxonomy and natural history. More general than thesemethods and including both are the interrelated methods of struc-tural and functional analysis. Structural analysis has to do withthe patterns of organization of things. Functional analysis has to dowith the processes or modes of activity. The two are intimately con-nected in that the organism’s structures make possible its activitiesand the functional demands made upon it give rise to its organized pat-terns. In modern biology the concept of dynamic process is consideredmore fundamental than that of static design. Therefore, functionalanalysis has theoretical priority over structural analysis. Taxono-my belongs to structural analysis, and natural history to functionalanalysis. This confirms the previously mentioned theoretical priorityof the method of natural history in biology over the method of classi-fication. In addition to taxonomy, structural analysis includes descrip-tions of the forms of living things both internally and in their rela-tionships with each other. One of the central concepts of biology isorganization. Biology is, in fact, the study of the patterns of orga-nization of living things. Concern for organization is not peculiar tobiology. It is the condition for intelligibility in any field of inquiry. It
BIOLOGY 185was illustrated in our discussion of language patterns and of thestructures of matter and energy in the physical world. What is pecu-liar to biology is the kind of organization exhibited by living things.This distinctive type of organization is the clue to all understandingof the world of life. LIVING THINGS HAVE THEIR OWN KINDS OF ORGANIZATION A living thing has a particular kind of organization constitut-ing it an organism. An “organism” is a patterned whole composed ofinterdependent coordinated parts. But not all organized wholes areorganisms. Atomic nuclei, atoms, molecules, crystals, geological for-mations, and astronomical systems also have intelligible structures,with parts functioning interdependently. Loving things have their ownspecial kinds of organization that are made possible through theunique bonding properties of the element carbon. This element is struc-tured in such a way that compounds of great complexity and virtual-ly boundless variety can be built from it, using other elements,chiefly hydrogen, oxygen, nitrogen, and phosphorus. Especially impor-tant for life are the linked carbon compounds. These include glucose,glycerine, fatty acids, amino acids, pyramidines, purines, polysaccha-rides, fats, proteins, enzymes, nucleotides, nucleic acids, and finally,nucleoproteins, the largest known molecules, having the remarkableand singular property of self-duplication. These highly complex self-duplicating organic compounds com-prise the unique substance protoplasm, of which all living things con-sist. This living substance is itself further organized into a variety ofstructures, most basic of which are the cells. Cells, together withother noncellular protoplasmic materials such as fibers and bodyfluids, are the constituent parts of a vast hierarchy of organic pat-terns in which each successive level has greater structural complexi-ty, larger size, more energy requirements, and more instability thanthe lower levels. Aggregates of cells with similar functions comprisetissues. Cooperative aggregates of tissues form organs. These are inturn coordinated into organ systems, and finally into complete or-ganisms. Organisms are further organized into families and soci-eties, with specialization and division of labor as the basis of cooper-ation, mutual aid, and increased efficiency. STRUCTURE EXTENDS TO THE FORMATION OF COMMUNITIES AND DIFFERENT SPECIES LIVING IN A SYMBIOTIC RELATIONSHIP Structure extends even beyond the society level in the forma-tion of communities. These are local associations of interdependent or-ganisms of different species, living in a symbolic relationship, withmember populations specializing and serving one another either mutu-ally or parasitically in respect to food, reproduction, and protec-tion. Finally, living communities are organized, with the physical envi-ronment, into the entire world of living things, forming the total in-teractive rhythmic pattern of animate existence.
186 PART TWO: FUNDAMENTAL PATTERNS OF MEANING The main focus of early studies of biological sciences was that of collection and classification of species. Biological sciences have evolved well beyond that basic task. If the science is at a higher level today, should a student begin at a higher level than a student of 50 or 100 years ago began?
188 PART TWO: FUNDAMENTAL PATTERNS OF MEANING CHARACTERISTIC ACTIVITIES OF LIVING THINGSMetabolism and Self-Perpetuation As indicated earlier, organic structures cannot really be ex-plained apart from their functions. If an understanding of the partic-ular patterns of living things is to be attained, the characteristic ac-tivities in which they engage must be described. Every organism hastwo broad categories of functions: metabolism and self-perpetua-tion. “Metabolism” refers to the processes by which the organismdraws in, transforms, incorporates, and returns matter and energyfrom the environment. “Self-perpetuation” includes the activities thatenable the organism to persist through time in spite of disorganizingforces both outside and within.Nutrition, Respiration, and Synthesis Metabolism comprises three main processes: nutrition, respira-tion, and synthesis. Nutrition is the activity of supplying the organismwith the raw materials of life. Some organisms have autotrophic nu-trition, that is, they live on inorganic substances from the environ-ment, which others are heterotrophic, requiring supplies of organicnutrients. The most important autotrophs are the green plants, thatuse light to transform water and carbon dioxide into carbohydrates inthe process of photosynthesis. Animals, on the other hand, are het-erotrophic, ultimately depending on plants for their nutriments. Ofspecial interest is the fact that the structures of both plants and an-imals are in part explainable by these nutritional activities. Plantsare structured with roots, leaves, and other parts for direct andcontinuous association with the inorganic environment. Animals, de-pending for their food on other living things, require skeletons andmuscles for locomotion, together with chemical and neural coordina-tion systems for rapid adjustment to encountered objects. Animalsalso need alimentary and circulatory mechanisms for the ingestion,digestion, absorption, and transport of nutrients, and for the ejectionof waste products. Animal and plant organization specifically re-flect different ways of life, involving different means of exploitingthe environment to obtain nutriment.Respiration The organism secures energy from the nutrients through thesecond metabolic process, respiration. In most animals and plants en-ergy is released through oxidation. For this function various struc-tures for bringing in oxygen and taking carbon dioxide away are de-veloped. Gas exchange is more direct with plants than with animals,that require breathing and circulation systems to effect gas ex-changes for the cells not directly exposed to the atmosphere.Synthesis Finally, the energy released in respiration is utilized by thecells for the synthesis of new protoplasm by means of complicatedenzyme reactions. CHARACTERISTIC FUNCTIONS OF LIVING THINGS While the three metabolic functions are necessary to life, theyare neither sufficient nor really distinctive to living organisms. Non-
BIOLOGY 189living systems can also be devised so as to take in, transform, andutilize materials from outside themselves. The characteristic functionsof living things are those connected with self-perpetuation, the mean-ing of which is the key to all biological understanding. Living thingsare open systems exchanging matter and energy with their surround-ings in such a way as to perpetuate themselves. Self-perpetuation in-cludes three kinds of functions: steady-state control, reproduction,and adaptation.Steady-State Control Steady-state control is the process of maintaining stability inthe organism in the face of changing internal and external conditions.Structures effecting such control are (a) genes, that guide proteinsynthesis in accordance with code patterns reflecting the structure ofthe entire organism, thus making each cell act in relation to the planof the whole, (b) vitamins and hormones, that regulate the cells’metabolic functions, (c) excretory and circulatory systems, thatmaintain a suitable environment for cells within the body, and (d)nervous systems, that effect the coordination of the whole organismand receive, transmit, transform, and store information from the en-vironment.Reproduction Reproduction is possible because of the self-duplicating powerof living substances. Under the guidance of the genes new cell struc-tures are reproduced from existing ones. A process of development oc-curs in which cells divide and are differentiated according to theirfunction within the whole organism.Adaptation Adaptation is the process of adjustment of the organism to itsenvironment, enabling it to survive, prosper, and proliferate. Themechanisms for adaptation are those of evolution, through which neworganic forms arise and are perpetuated, or not, in accordance withtheir degree of adaptation and therefore of reproductive capacity.As earlier indicated, sexuality is not primarily an instrument of re-production (though by means of it new organisms of similar kind aregenerated). Sexuality is a source of fresh trait combinations in theprogeny, that are then subjected to the process of natural selection,resulting in the perpetuation of the best adapted types. The analysis of adaptation brings us at last to the theoreticalbasis for the understanding of the taxonomic classes with which bio-logical description begins, and the study of the world of life comesfull circle. MEANINGS IN BIOLOGY ARE EMPIRICAL, FACTUAL, DESCRIPTIVE, AND ULTIMATELY GENERAL AND THEORETICAL IN ORIENTATION Summing up, meanings in biology, as in all other sciences, areempirical, factual, descriptive, and ultimately general and theoreti-
190 PART TWO: FUNDAMENTAL PATTERNS OF MEANINGcal in orientation. The distinctive features of biological meaningsarise from the special subject matter studied, namely, living things.The unique property of living things is their power of self-perpetua-tion, supported by the processes of metabolism. Corresponding tothese basic life-functions are characteristic organic structures, con-stituting open systems arranged in hierarchies of increasing complexi-ty and interdependence of differentiated parts. Finally, biologicalideas express dynamic principles in which individual organisms and kindsof organisms are traced developmentally and in evolutionary per-spective, yielding theoretical understanding both of individual livingthings and of the multitude of kinds of animate creatures inhabitingthe earth. WAYS OF KNOWING1. What are the most significant differences between life sciences and the sciences of physical nature?2. How is a thing considered to be alive?3. Why is biology considered an autonomous science?4. Why is the process of classification known as “taxonomy” im- portant in the systematic study of living things?5. Why is the fundamental unit in biology important?6. Why is the process of classifying natural objects as part of the descriptive task important to any science?7. In the search for meanings, why do biologists use the method of natural history?8. Why is the concept of evolution in natural history a ruling idea in biology?9. Why are the interrelated methods of structural and functional analysis important to biology?10. How living things have their own special kinds of organization?11. What is meant by saying that structure extends to the forma- tion of communities and different species living in a symbiotic re- lationship?12. What are characteristic activities of living things?13. Why are living things considered to be open systems?14. Self-perpetuation includes what three kinds of functions?15. Why are meanings in biology ultimately general and theoreti- cal in orientation?