Science in Christian Perspective

 

A Persistent View: Lamarckian Thought in Early Evolutionary Theories and in Modern Biology

Harry Cook* and Hank D. Bestman*

Department of Biology
  hcook@kingsu.ab.ca hbestman@kingsu.ab.ca 
The King's University College 
Edmonton, Alberta T6B 2H3

From: Perspectives on Science and Christian Faith 52 (June 2000): 86-97.

Jean Baptiste Lamarck (1744-1829), an influential French biologist, made important contributions to biological knowledge and theory, and spun speculative theories about natural phenomena. In this paper we describe how his theory of inheritance of acquired characteristics--largely discounted by modern genetic knowledge--was often appealed to by many biological and religious thinkers of the late nineteenth and early twentieth centuries, to give a sense of purpose to theories of evolutionary change. Recent biological observations have renewed the currency of Lamarckian theory, but in a way that appears to be compatible with modern biological thought. This paper concludes with a discussion of reasons that explain why Lamarckian theory has continued to appeal to biologists and other thinkers throughout this century.

When we examine the work and influence of Jean-Baptiste Lamarck, it is as though we deal with two people: the Jean-Baptiste Lamarck who lived and worked in Paris, and the Lamarck that biologists have made of him. The first developed grand theories about geology, weather, physical phenomena, living organisms, and evolution, and was also an excellent naturalist and classifier of invertebrates. The second is the one who lives in biologists' collective memories: he is most often remembered as a person who espoused macroevolution, thus paving the way for Darwin's theories, and who postulated the inheritance of acquired characteristics (IAC). This second picture of Lamarck selectively reduces the scope of his theorizing, and also gives him sole credit for theories that were held by many others during his time. In this paper,1 we will describe briefly the life and work of Lamarck. The major theme of our paper is an examination of how biological thinkers incorporated selected Lamarckian ideas into their theories. The concept of IAC was used by several such thinkers to make evolution theory more acceptable to themselves and to other thinkers of their time. In other cases, IAC has been suggested as the explanation for some modern biological observations. Finally, we will discuss some possible reasons that explain why the theories of Lamarck have been remarkably long-lived.

Lamarck's Life and Work

Several authors who discuss the influence of Lamarck include a short biography: Lamarck received a Jesuit education, did a brief stint in the French army (many remark on the poor quality of his horse), and moved to Paris in 1768 to engage in field studies of plants and in writing some undistinguished, paid manuscripts. Lamarck's first important biological work, a four-volume work on the flora of France, earned him praise from many aristocratic, amateur naturalists and, more importantly, from Georges Louis Leclerck de Buffon (1707-1788). Buffon chose Lamarck to tutor and travel with his son, and later secured Lamarck a position as assistant in the botanical department of the Natural History Museum in France. Much of Lamarck's speculative theorizing about weather, geology, physical phenomena, and processes in living organisms began during this period. After the French Revolution, Lamarck was appointed to the Jardin des Plantes (renamed from the Jardin du Roi) in 1793, as one of the two successors of Buffon, and he was charged with the study of the "inferior animals," or the invertebrates, as he himself came to call them.2

Much of Lamarck's biological work during this period was published in his Philosophie Zoologique in 1809.3 In this book, we find a mixture of speculative theorizing and accurate observational biology. His speculative theorizing can be noted in the roles he assigns to visible and invisible fluids in organisms. His accurate observation is exemplified by his exposition of animal classification, a classification that includes his foundational work on the invertebrates. Pertinent to the present paper are the mechanisms suggested by Lamarck that are capable of effecting macro- and micro-evolutionary change.

In Philosophie Zoologique, Lamarck suggests that all living organisms can be arranged on a linear scale of complexity, and postulates separate scales for animals and plants. Most of his discussions are applied to animals, and his evolution theory is intimately related to the continuous scale of complexity that he discerns to be present in animals.4 This scale is not static: simple animals form by direct generation at the bottom while an increase in complexity--he does not use the word "evolution"--brings animals closer to the top of the ladder, which is occupied by mammals.5 Peter J. Bowler suggests that according to Lamarck, such changes in organisms over time have two major causes: "an inherently progressive trend that forced living things gradually to ascend the chain of being, and the inheritance of acquired characteristics as a mechanism for adapting them to an ever-changing environment."6

In a recent series of two articles on the significance of Lamarck, Stephen J. Gould proposes that the first of these two tendencies gives rise to an increase in complexity, an orderly climb up the ladder of evolution, resulting in predictable, unidirectional progress, while the second mechanism, based on the use and disuse of animal parts, and passed on through IAC, produces diversity and increasing adaptation to a changing environment.7

Lamarck's theory of tendency toward increasing biological complexity was greatly influenced by the idea of the Great Chain of Being, because he saw an increasing level of perfection in the animal world. He initially assessed perfection "simply in terms of complexity" but after 1800 he began to believe this perfection was due to an increasing level of evolution.8 Thus, as a species became more complex, it moved up the Great Chain of Being. Several authors suggest that the ideal of progress, prevalent in Lamarck's time, inspired these theories.9 Lamarck was not the first biological thinker to place importance on the Great Chain of Being, or to attribute an evolutionary aspect to it. Arthur Lovejoy, in his important and fascinating book, The Great Chain of Being, describes how the concept originated in Plato's thinking, was elaborated upon in Scholastic thought, "temporalized"--given an evolutionary meaning--by such Enlightenment thinkers as Diderot, Maupertuis, and Robinet, and radically altered by Romantic thinkers such as Schelling and Oken. It is remarkable that Lovejoy does not include Lamarck in his survey.10

In summary, Lamarck's linear, progressive evolution culminated in the appearance of humankind; organisms climbed a ladder of complexity that was based on the idea of the Great Chain of Being. Thus, Lamarck's vision of evolution has a sense of purpose and progress; that is, it can be characterized as teleological. Later in his career, Lamarck became convinced that the Chain could not be a single lineage, and he acknowledged the presence of numerous branches in the evolution of species.11 This is a vital insight, and it makes the later Lamarck a missing link between Lamarckism and Darwinian natural selection.

Lamarck and Darwin

Lamarck's ideas continued to have great impact, even during and after the time of Charles Darwin (1809-1882). Lamarck and Darwin were the authors of the two most important theories in evolutionary thought; therefore, it is appropriate to ask: Was Darwin acquainted with Lamarck's work? Did he adopt any of Lamarck's theories? How were his theories different from those of Lamarck? We will discuss these topics briefly, and then examine how Darwin's contemporaries and followers were influenced by Lamarckian patterns of thought, and particularly by the concept of IAC. Bowler has written several valuable assessments of Lamarckian and neo-Lamarckian theories, and he has discussed the use of these two terms as they appear in the work of thinkers after Darwin.12

In his Origin of Species, Darwin makes reference to Lamarck's ideas on macroevolution. In personal correspondence, Darwin was quite dismissive of the French biologist's work, but, always a gentleman, he explicitly acknowledges Lamarck's work in the Origin.13 The fact that the well-known and respected Lamarck put forward theories (after 1800) that suggest the occurrence of macroevolution must have affected Darwin more than the references in his writing indicate.


[Darwin] maintains a critical stance
toward Lamarck's work, and continues to make variation 
and natural selection important pillars for his thought,
but he admits that an organ can enhance or change
its structure, particularly in response to use, and that 
these changes can be passed on to generations that follow.


In the Origin, Darwin accepts that acquired characteristics may be inherited where he finds it necessary or desirable to do so. He maintains a critical stance toward Lamarck's work, and continues to make variation and natural selection important pillars for his thought,14 but he admits that an organ can enhance or change its structure, particularly in response to use, and that these changes can be passed on to generations that follow. Thus, in the opening pages of Chapter V, Darwin states: " I think there can be no doubt that use in our domestic animals has strengthened and enlarged certain parts, and disuse diminished them; and that such modifications are inherited." Darwin goes on to suggest that this is probably also the case in nature. This acceptance of IAC he shares with other biologists, including its most notable proponent, Lamarck.

In an excellent discussion, Michael Ruse states that Darwin considered IAC a "secondary mechanism."15 Yet, Darwin was not reticent to invoke Lamarckian processes and he suggested that IAC supports the evolutionary changes affected by his primary mechanism, natural selection. John Maynard Smith states:

Darwin was only a half-hearted Darwinist. He accepted Lamarck's ideas also, and even invented a process, pangenesis, which could account for it; he supposed that particles, or pangenes, passed from all parts of the body to the germ cells to convey information about acquired adaptations.16

Thus, the environment plays very different roles in the thinking of the two biologists. For Lamarck, the environment steers adaptive change by IAC, while in Darwin's thought, it performs the cruel but important task of selecting the fittest organisms.

Darwin might have acknowledged his intellectual debts to Lamarck more explicitly, if the differences between their evolutionary schemes had not been so great. Both thinkers were influenced by the idea of progress, prevalent in their times, but they differed remarkably in how they work out this influence in their theories. We noted that, for Lamarck's earlier thought, and for Lamarck's theories that present-day biologists tend to remember, evolutionary progress is unilinear and purposeful (teleological) culminating in the human species. Darwin did not believe, however, that humanity was the end goal of evolution. In his opinion, the human species was the farthest point of evolution, but this was not because everything was progressing toward it. Darwin felt that humanity was formed through a complex and unpredictable route and that each branch of the evolutionary tree was capable of producing more complex creatures over time.17

Darwin continued to struggle with the role that progress played in evolution. "There are many passages in the Notebooks [of Darwin] which suggest that he still hoped to show that evolution was, in the end, progressive," Bowler states in his biography of Darwin.18 Montgomery says that "Darwin believed that evolution was somehow a progressive process, yet he shared with Lyell and Malthus a deep skepticism about the idea of progress and employed it only cautiously in his book."19 Darwin wrote in the margin of his copy of Chambers' Vestiges of Creation: "Never use the word higher or lower."20 Instead we note an emphasis on specialization, adaptation, and differentiation. Yet, in the famous last paragraph of the Origin, Darwin mentions the rich variety of living organisms that has been formed by the processes described in his book.21

Darwin's book led to widespread acceptance of evolution, but his theory was often modified to suit religious thought of the times. Many people believed that the cruelty and arbitrariness of nature, which Darwin presented, were particularly objectionable. Therefore, the dialogue between religious thought of the time and a new scientific theory led, initially, to adjustments in both. Darwin's selectionism regained public acceptance in the early part of the twentieth century, and eventually prevailed because it was compatible with new theories in population genetics and evolution.

Given the influence of Lamarck, it is understandable that evolutionary schemes before the time of Darwin were developed along Lamarckian lines. British evolutionists such as Robert E. Grant (1793- 1874), Robert Chambers (1802-1871), and Herbert Spencer (1820-1903) are described well in Bowler's Charles Darwin: The Man and His Influence.22 Grant, who taught a course in invertebrates, was one of Darwin's lecturers in Edinborough. A confirmed Lamarckian thinker, he probably planted seeds of transformationism in the young Darwin's mind. Chambers anonymously published Vestiges of the Natural History of Creation in 1844. In this book, divinely guided mechanisms steer an evolutionary development that has a decidedly Lamarckian character. Spencer, who coined the phrase "survival of the fittest" and is often described as the originator of "social Darwinism," began to publish before the appearance of the Origin. His theories, linking biological evolution theory and social development, are based on individual competition and effort to succeed. These theories are Lamarckian in nature, suggesting "progress through struggle,"23 making the appellation "social Darwinism" somewhat of a misnomer.


Lamarckian Thought After
The Origin of Species


Most interesting for our theme is the impact of Lamarckian thinking, particularly IAC, after the publication of Darwin's most influential work, The Origin of Species. Two books by Bowler have convincingly shown that the natural scientists of the time replaced random variation and natural selection, the twin supports of Darwin's theory of evolution, with Lamarckian ideas of soft inheritance (where environment shapes inheritance, and acquired characteristics can be passed on to succeeding generations).24 Darwin, confined to his home by illness, was very successful in gathering about him a loyal group of followers and defenders. However, many of these "Darwinians" also postulated mechanisms for evolution that differed from Darwin's selectionism. Even Thomas Huxley and Asa Gray, loyal friends of Darwin, had reservations or differing theories.25 Thus, Darwin was successful in convincing the naturalists of his time that evolution had occurred, but the causes that were thought to underlie the process were not necessarily the ones Darwin suggested. A process that, for Darwin, was driven by the twin forces of random variation and cruel selection was infused with a sense of purpose and room for divine design. In this situation, theistic beliefs effectively shaped scientific explanation. Public pressure or personal conviction caused many thinkers to put a Lamarckian slant on evolution theories.


The natural scientists of the time replaced random variation and natural selection,
the twin supports of Darwin's theory of evolution,
with Lamarckian ideas of soft inheritance.


In his Monad to Man, Ruse describes two American paleontologists, often mentioned together as the Hyatt/Cope School.26 Although they were initially influenced by the archetypal, nonevolutionary thinking of Louis Agassiz (1807-1873), Edward Drinker Cope (1840-1897) and Alphaeus Hyatt (1838-1902) came to accept macroevolution, and they provided Lamarckian alternatives to the Darwinian evolutionary scheme. Both sought to insert a sense of purpose and direction in the evolution process as they saw it. For both men, the reasons for suggesting these alternatives were complex.

In his book, Birds, Beasts, and Men, H. R. Hays captures the spirit of adventure as paleontologist Cope and his arch rival, O. C. Marsh (1831-1899), search the American West for fossil skeletons of various kinds.27

Their excavations of dinosaurs caused much excitement, and are the source of important museum exhibits that are still on display today. Cope's Quaker upbringing and the influence of Agassiz caused him to initially reject transmutation theories. Gradually, however, he came to accept (or became willing to acknowledge in public) evolutionary views. Ruse suggests that these views were shaped by visions of progress and degradation and by his continuing religious commitments. Cope used Lamarckian theories to explain many of the changes wrought by nature.28

Hyatt was also influenced by the theories and strong personality of Agassiz, his teacher. Thus, he stressed theories of progression and degeneration and applied these to the existence of species. Unlike Agassiz, however, he adapted these theories to include evolution, passed on in a Lamarckian manner. Hyatt corresponded with Darwin and respected his suggestion that evolution took place, but Hyatt rejected the selectionist mechanisms that Darwin used to explain the process. In Hyatt's theorizing, too, religious views, especially about Providence, play a crucial role.29

Religious leaders in Great Britain and the United States also took a vital interest in the evolution debate. Some attempted to soften the controversial influence of Darwin's theories by putting a Lamarckian spin on them. A notable example is the British Anglican church leader and theologian, Charles E. Raven (1885-1964). Raven wrote an influential biography of the seventeenth century naturalist, John Ray. In his books on religion and science, Raven displays a curious mixture of orthodoxy and liberalism. In The Creator Spirit published in 1927, Raven suggests that the Holy Spirit is as active in creation as God the Father is. He rejects dualism between Spirit and matter, and between sacred and profane. He states that God is in the whole, including in evolutionary processes.30

In regards to biological theory, Raven expresses his admiration for Henri Bergson's vitalistic philosophy, particularly his concept of elan vital (vital impetus). In his criticisms of mechanistic biological theories and of aspects of evolution theory, Raven leans heavily on the work of the early French ethologist, J. H. Fabre, and on the observations of others about animal behavior.31 Raven accepts the occurrence of evolution, but the strain of evolutionism he posits is not one that modern-day theoreticians would support. He stresses the efficacy and importance of "use-inheritance" (Lamarckianism) and criticizes selectionism. Remarkably, Darwin escapes the brunt of Raven's critique, because Darwin accepts some degree of use-inheritance in later versions of the Origin. However, the deterministic and mechanistic genetic theories of August Weismann and Gregor Mendel do not escape as easily.32 Raven's theories in support of vitalism, and particularly of use-inheritance, are brought forward deductively. That is, they are postulated because Raven needs them; necessity becomes the mother of invention. A good description of Raven's life, work, and thought is given in a biography by F. W. Dillistone and in an article on another theologian of the time by Bowler.33


Many [Protestant religious leaders and theologians in Britain
and the United States] proposed a variety of suggestions, 
all intended to reduce the importance of natural selection 
and to bring back a sense of purpose in the processes of change.


Raven was not isolated in his ideas about the relationship of religion to evolution. James Moore and David Livingstone each show that, in the late nineteenth century, many Protestant religious leaders and theologians in Britain and the United States readily accepted evolutionary theories. The kinds of evolutionary schemes they were willing to consider varied widely from person to person, but it is clear that many supported Lamarckian mechanisms of change.34 Some of these thinkers stressed inherent tendencies for complexification, while others emphasized inheritance of acquired characteristics. In fact, many proposed a variety of suggestions, all intended to reduce the importance of natural selection and to bring back a sense of purpose in the processes of change.

Christian Darwinists ... found in Lamarckian evolution the "spiritual dimensions by which Darwinism could be reinterpreted or transformed." The main hindrance to the accomplishment of God's purposes in nature was natural selection. Darwin called it "the most important, but not the exclusive, means of modification." This statement needed alteration if some sort of teleology were to be preserved.35

One cannot escape the impression that these writers were casting about, anxious to do justice to Darwin's new theory, yet looking for alternatives to the parts of his theory that they felt were objectionable.

When the theories of Weismann and Mendel took hold in the first decade of the twentieth century, Darwinism decisively prevailed over Lamarckian schemes of evolution. Nevertheless, some Lamarckian approaches persisted in a few, well-documented cases. In these cases, it was especially the theory of inheritance of acquired characteristics that was the strand of Lamarck's work to persist. Paul Kammerer's work on the mating pad of the toad, Alytes, and T. D. Lysenko's policies for plant breeding in the former Soviet Union, received much attention.36 Though both studies have been thoroughly discredited, they demonstrate a continued fascination with the once-prevalent theories of Lamarckian improvement.

Kammerer, an Austrian biologist who worked in the first few decades of the twentieth century, suggested that a species of toad, Alytes obstetricans, which does not return to the water to mate and which has lost the characteristic mating pad on the thumb, regained this pad in strains reared in wet conditions. This claim led to much controversy, for it became apparent that Kammerer or someone else had tampered with the preserved forelimbs. Attempts to reproduce Kammerer's results were not successful. Kammerer lost most of his remaining support when he committed suicide in 1926. However, Arthur Koestler supported Kammerer, as much as was possible under the circumstances, in his 1971 book, The Case of the Midwife Toad.37


Lamarck's reputation suffered when scientists did
questionable research and
related their work to his ideas.


Lamarckian theory also had regrettable impact when the genetic theories of Lysenko (1898-1976) were made official policy in the Soviet Union from 1948 to the mid-1960s. Lamarckian thought had retained considerable support in the Soviet Union during the early part of this century when the rest of the world was switching to Darwinian theories.38 Lysenko built on this base, spreading his own ideas from the late 1920s. By 1948 many reputable geneticists had been purged from official Soviet positions, paving the way for Lysenko's takeover.39

 Lysenko claimed that the vernalization of wheat, a procedure in which seed grain is given a cold shock in order to improve germination, would lead to permanent genetic improvements. This claim led to similar programs by state agencies for other agricultural crops. While increased care for crops can lead to increased yields, the theory that it can also lead to genetic changes is not supported by current knowledge. Lysenko's influence made a scandal of Soviet agricultural science and research.40 Thus, Lamarck's reputation suffered when scientists did questionable research and related their work to his ideas.

Lamarckian Ideas in the Era of Molecular Biology

Lamarckian ideas have an influence on some modern biological thinkers as well. Ted Steele's theories about the inheritance of acquired immunological capabilities and John Cairns' articles on directed evolution in bacteria marked the beginning of a new round of experiments that were explained with Lamarckian theories. More recently, the investigations of Otto E. Landman and a book by E. Jablonka and M. J. Lamb have helped to bring Lamarckian inheritance to the fore. As we discuss the work of these scientists, we will note that it appears to be compatible with modern genetic knowledge and places itself solidly within the modern biological paradigm. Thus, these thinkers differ significantly from the Lamarckians described in the previous section.

Steele, an immunologist working at the University of Toronto in the 1970s, renewed attempts to give credence to the inheritance of acquired characteristics.41 Acknowledging his theoretical kinship with Arthur Koestler, Steele stated that some immunological capabilities can be passed from rabbits to their offspring. Steele suggested that this is an indication that there can be a transfer of DNA from somatic to germ line cells. While scandal or hints of fraud have not tainted his efforts, as was the case with Kammerer and Lysenko, Steele's work nevertheless has not been confirmed and has not received wide support. Others suggest that Steele's suggestions are in a very specialized area, and it is not warranted to draw the more general conclusion of Lamarckian inheritance from them.42 According to Steele, one reason for resurrecting Lamarckian theory is to account for the direction and the speed of evolutionary change, aspects of evolution that Darwinian processes do not explain adequately.

Cairns, a respected present-day British microbiologist and cell biologist, recently reported that bacteria can alter their ability to metabolize various substrates after exposure to media with nutrients that the bacteria had not encountered before.43 This suggests that the environment (the new medium) induced genetic changes in the bacterial hereditary make-up. This work on directed evolution has been discussed seriously, in light of the reputation of the authors and the quality of the work reported. However, other interpretations of the results have been suggested.44 Recently, other workers suggested that the transfer of viral DNA segments can explain the observations from Cairns' laboratory.45

Recently Landman reviewed the occurrence of the inheritance of acquired characteristics.46 In his survey, Landman reconsiders the subject of the IAC in the light of our present understanding of molecular genetics. Systems that display IAC conform to the following experimental pattern: Individual organisms or cultures of cells incubating in a particular environment are exposed briefly to a chemical or physical treatment under conditions that allow little or no growth (thereby ruling out selection of mutants). Following the exposure and upon being returned to the original environment, all or a large portion of the treated cells (or organisms) exhibit new characteristics that are passed on heritably to succeeding generations.

Landman describes and gives examples of different mechanisms of heritability that all give rise to this kind of IAC47 and relates these mechanisms to three possible modes of induced inheritance first distinguished by the molecular biologist Joshua Lederberg: extranucleic inheritance, epinucleic inheritance, and nucleic inheritance.48 In extranucleic inheritance, there is a stabilization of gene expression without any attendant change in nucleic acid sequence. This type of inheritance is illustrated by the maintenance of the induced state in the lac operon of E. coli,49 and the wall-less state of Bacillus subtilis.50 Epinucleic inheritance refers to the alterations in DNA substituents such as methyl or glycosyl groups without attendant change in nucleic acid sequence.51 The epigenetic inheritance known as genomic imprinting52 appears to be due largely to selective DNA methylation. Nucleic inheritance refers to the removal or addition of foreign nucleic-acid containing elements such as plasmids, viruses, or bacteria. In this case, a specific set of genes is either eliminated or added to an organism. The carbon dioxide-sensitive Drosophila is an example of this induced inheritance.53

Landman's review is a clear demonstration of the broadening of the concept of IAC from that originally formulated by Lamarck.54  According to Lamarck, an animal's use or disuse of an organ affected that organ's development in the animal's offspring. The use of the word "acquire" in this context conforms to only one of the definitions of Webster's Dictionary: (a) "to gain as a result of effort or experience." The other two definitions of the word acquire are: (b) "to come into possession of" and (c) "to come to have as a characteristic." Landman's mechanisms of heritability are examples of these latter two definitions of acquire and, thus, broaden the meaning of "Lamarckian" from the way it was originally used.

Though at first glance the inheritance of acquired characteristics reviewed by Landman resembles the Lamarckian concepts of environmentally-induced inherited changes, the distinction between them lies in the recognition that acquired inheritance is not a universal mechanism of inheritance as implied by Lamarck, but is instead one of the many facets of molecular genetics. Molecular genetics has room for both Mendelian inheritance and the inheritance of acquired traits. Acquired characteristics of the extranucleic, epinucleic, or nucleic types can become heritable in single-cell systems. However, only characters of the nucleic type can pass the germline barrier of multicellular organisms.


What eventually came to be termed "Lamarckian"
included traits changed
by use or disuse,
but also included passively acquired mutations and
characters directly induced
by the external environment,
without the behavioral mediation
required by Lamarck.


In their 1995 book, Epigenetic Inheritance and Evolution: The Lamarckian Dimension, Jablonka and Lamb make the case that there are mechanisms by which some acquired characteristics can be transmitted to the next generation and that such traits have probably played a significant role in evolution.55

The Lamarckian dimension to this transmission of acquired characteristics is again based on a broadening of the original concept proposed by Lamarck. What eventually came to be termed "Lamarckian" included traits changed by use or disuse, but also included passively acquired mutations and characters directly induced by the external environment, without the behavioral mediation required by Lamarck. This change is reflected in Jablonka and Lamb's working definition of the inheritance of acquired characteristics. According to them, such inheritance has occurred if:

1.the environment induces the change in the characteristic;

2.the induced change is specific and repeatable, although not necessarily adaptive;

3.a specific change in hereditary information is involved;

4.the change is transmitted to the next generation.56

This definition of inheritance of acquired characteristics conforms to Mayr's definition of soft inheritance.57 However, it avoids the use of the phrase "genetic material," which is usually assumed to be synonymous with DNA. Jablonka and Lamb's definition allows for the possibility that heritable information can be carried in ways other than in the sequence of bases in DNA.

Jablonka and Lamb discuss a wide range of different types and mechanisms of Lamarckian inheritance.58 Some of these involve conventional Mendelian genetic transmission while others are based on epigenetic inheritance systems. These mechanisms are often downplayed or dismissed because they do not fit in with the current biological paradigm that defines heredity as the presence of identical genes in ancestors and descendants. However, this paradigm represents a restricted concept of heredity in that it focuses entirely on the primary base sequence of DNA and does not allow for additional systems that can transmit information between generations.

A survey of Lamarck's influence would not be complete without mention of two biological topics that have Lamarckian aspects; that is, they are related to the inheritance of acquired characteristics. First, recombinant DNA technology can transfer genetic characteristics into a wide variety of organisms; here, in a very real way the environment--the biological laboratory--shapes the genome of the organism being manipulated. Second, the postulated evolutionary origin of some cellular organelles, notably chloroplasts and mitochondria, should also be considered. Audaciously suggested at first, but now widely accepted by a large segment of the biological community, the theory of endosymbiosis suggests that chloroplasts and mitochondria in eukaryotic organisms were acquired by the internalization of simple prokaryotic organisms capable of photosynthesis and aerobic metabolism.59

A Persistent View

We may conclude that appeals to Lamarckian or neo-Lamarckian mechanisms to explain biological observations occur with persistent frequency. In some cases, such mechanisms offer a ready explanation for experimental results; in others they are suggested for theoretical reasons. In this last section, we will suggest some causes for the durability of the Lamarckian model.

Lamarckian theory can insert a sense of purpose and wisdom into the evolution hypothesis. Hull says:

Lamarck is far from dead ... The inheritance of acquired characteristics is one of those ideas that holds out eternal fascination. It seems so right. If only inheritance were Lamarckian, evolution would be orderly, and efficient.60

An objective in some modern appeals to Lamarckian explanations is to account for the speed and progress that the evolution process has been able to achieve. Steele specifically makes this point in his first book.61 Hull has countered this by suggesting that if evolution moves too fast, organisms would respond to every change in a fickle environment, and that this would actually be non-adaptive: If faster evolutionary change by Lamarckian means would be adaptive, it would have evolved long ago!62

Thus, Hull suggests that there may be some advantage to biological organisms not responding to transitory changes in ecosystems.


Lamarckian theory can insert
a sense of purpose and wisdom into the evolution hypothesis ...
[and can] account for the speed and progress that
the evolution process
has been able to achieve.


Another reason for the longevity of Lamarckian concepts is the fact that human culture is passed down through the generations in a Lamarckian manner; acquired changes in language, religion, and other cultural practices can be transmitted to succeeding generations. This phenomenon has led Richard Dawkins to his notion of "memes" in The Selfish Gene and The Extended Phenotype.63 He defines meme as a "unit of cultural inheritance, hypothesized as analogous to the particulate gene, and as naturally selected by virtue of its 'phenotypic' consequences on its own survival and replication in the cultural environment."64 It is ironic that the term meme has been coined to stress the similarity between the inheritance of cultural practices and biological heredity while the transmission of memes and genes depend on entirely different mechanisms.

This discussion of Lamarck and Lamarckian theories raises a final question: Does Lamarckian theory explain data or does it reflect the social interests of the person or group who formulates or accepts it; in other words, are scientific theories discovered or invented? With the burgeoning interest in history and sociology of science, such questions are being asked with increasing frequency. A quick and ready answer is this: "A theory can do both." We must understand, however, that in some cases the ideological interests of the theory are more clearly to the fore, and more determinative of a theory, than in others. We should not be surprised to find that human interests are commensurate with the structures of creation, given that human beings are an integral part of created reality. In some cases, Lamarckian theory can be used because it is thought to explain the data; Cairns is not known for his Lamarckian viewpoints, yet he invoked a Lamarckian explanation because it seemed applicable to the data he collected. In other cases, a scientist or writer appears to have an a priori interest in Lamarckian inheritance patterns, as we saw in the work of Steele and of Koestler; in such cases Lamarckian theory can represent social or religious interests.65 In our survey of Lamarckian thought, it also became clear that religious and sociological opinions played a major role in the acceptance of the Lamarckian model. Bowler states:

We are not asserting that the scientist has unlimited freedom to create ideas that bear no relationship to reality, but we must accept that to some extent our perception of reality is a social process and that scientists cannot escape this fact.66

Lamarckian theory is a controversial chapter in the history of biological thought; perhaps it is a chapter many biologists would like to forget. Nonetheless, this theory was often invoked in early stages of the development of evolution theory. Yet, even as we note this, phenomena that fall outside biological theory as it was formulated twenty years ago cause biologists to have a second look at Lamarckian inheritance. Lamarckian theory has appeared, and will probably continue to appear in various guises, providing color, ideas about alternative inheritance patterns, and new ways of looking at nature, as well as inspiring science, and, regrettably, pseudoscience.

Acknowledgments

We thank Natalie Cook, Jeffrey Dudiak, Shawn Leenheer, Michael Roberts, Henry Schuurman, and an anonymous reviewer for helpful suggestions about this paper.

Notes

1Paper presented at the conference of the American Scientific Affiliation and Christians in Science at Cambridge, UK, Aug. 2-5, 1998.

2For short accounts of Lamarck's life see R. Burkhardt, The Spirit of System: Lamarck and Evolutionary Biology (Cambridge, MA: Harvard University Press, 2d ed., 1995); "The Zoological Philosophy of J. B. Lamarck" in J. B. Lamarck, Zoological Philosophy: An Exposition with Regard to the Natural History of Animals (Chicago: University of Chicago Press, 1984); E. Mayr, The Growth of Biological Thought: Diversity, Evolution, and Inheritance (Cambridge, MA: Belknap Press of Harvard University Press, 1982), chap. 8. Other biographical information is presented in the eulogy by Georges Cuvier delivered at Lamarck's funeral, known for its bias against Lamarck, published in 1836, now available in Zoological Philosophy.

3Lamarck's Philosophie zoologique (1809), is available in English in Zoological Philosophy.

4Zoological Philosophy, chaps. 5, 6, and 8. A few simple invertebrates are difficult to fit into this scheme, and Lamarck puts these into a separate category.

5Instead, Lamarck uses the word "transmutation"; as one might expect human beings are at the top of the ladder in most of his presentations, e.g. in Zoological Philosophy. For discussion see: P. J. Bowler, The Eclipse of Darwinism: Anti-Darwinian Evolution Theories in the Decades around 1900 (Baltimore: The Johns Hopkins Press, 1983), chap. 4. 

6Bowler, The Eclipse of Darwinism, 58.

7S. J. Gould, "A Division of Worms; The Use and Disuse of Lamarck," Natural History (February 1999); "Branching Through a Wormhole: Lamarck's Ladder Collapses," Natural History (March 1999). Similar descriptions of these two tendencies are presented by M. Ruse, Monad to Man: The Concept of Progress in Evolutionary Biology (Cambridge: MA, Harvard University Press, 1996), 43-9; Bowler, The Eclipse of Darwinism, chap. 4.

8Mayr, Growth of Biological Thought, 345-6.

9P. J. Bowler, The Invention of Progress: The Victorians and the Past (Oxford, UK: Basil Blackwell, 1989), 137; Ruse, Monad to Man, 42-55.

10A. O. Lovejoy, The Great Chain of Being; A Study of the History of an Idea (Cambridge, MA: Harvard University Press, 1936). Mason describes the same thinkers in a chapter on the Great Chain, and also includes Lamarck in S. F. Mason, A History of the Sciences (New York: Collier Books, MacMillan Publishing Co., new rev. ed., 1962), chaps. 28 and 29.

11Mayr, Growth of Biological Thought, 350-1.

12In The Eclipse of Darwinism (p. 58), Bowler suggests that "Lamarckian" is generally used to refer to the inheritance of acquired characteristics. "The term 'neo-Lamarckism' was coined in 1885 by the American scientist Alpheus Packard" as an alternative to Neo-Darwinism. In this paper, we will use "Lamarckian" as referring to patterns of thought that depend on the inheritance of acquired characteristics unless we specifically state otherwise. Some authors prefer "use-inheritance" instead of IAC.

13A. Desmond and J. Moore, Darwin: The Life of a Tormented Evolutionist (New York: Warner Books, 1991), 315, 319, discusses Darwin's criticism of Lamarck in private correspondence; in the historical sketch added to later editions of the Origin by Darwin, he acknowledges Lamarck's contributions in a positive way, but there are few references in the book itself. See also D. Hull, "Lamarck Among the Anglos" in Zoological Philosophy, xlvii.

14Mayr, The Growth of Biological Thought, chap. 11.

15Ruse, Monad to Man, 139.

16J. Maynard Smith, "Regenerating Lamarck," Times Literary Supplement (October 24, 1980): 1195. This raises the well-known and provocative question: Was Darwin a Darwinian? Bowler has raised a similarly worded question regarding Mendel in The Mendelian Revolution: The Emergence of Hereditarian Concepts in Modern Science and Society (Baltimore: The Johns Hopkins Press, 1989), 8.

17P. J. Bowler, Charles Darwin: The Man and His Influence (Oxford: Basil Blackwell Ltd., 1990), 158.

18P. J. Bowler, Charles Darwin: The Man and His Influence (Oxford: Basil Blackwell Ltd., 1990), 158.

19W. Montgomery, "Aspects of Darwin," Science 252 (1991): 992-3, a review of Bowler's Charles Darwin.

20Bowler, Charles Darwin, 107.

21Ruse has discussed the concept of progress in Darwin's thought in Monad to Man, chap. 4; and in Hull, chap. 31, "Evolution and Progress" in The Philosophy of Biology, ed. D. L. Hull, and M. Ruse, (Oxford: Oxford University Press, 1998).

22Bowler, Charles Darwin. Other books by Bowler mentioned in this article also discuss these biological thinkers.

23Bowler, The Eclipse of Darwinism, 153.

24Ibid.; and P. J. Bowler, The Non-Darwinian Revolution: Reinterpreting a Historical Myth (Baltimore: The Johns Hopkins Press, 1988).

25Several authors have commented on Darwin's success in gathering around him a circle of defenders and followers; see, for example Desmond and Moore, Darwin, Ruse, Monad to Man. Thomas Huxley, Darwin's pugnaceous advocate accepted the idea of evolutionary change on the basis of morphological evidence, but he was less convinced about (Darwinian) selectionism or, for that matter, Lamarckian mechanisms (Bowler, The Non-Darwinian Revolution, chap. 4). Asa Gray, the American botanist, carried on an active correspondence with Darwin, but made it clear that for religious reasons he differed substantially with Darwin's theories (Ruse, Monad to Man, 245-50). See M. B. Roberts, "Darwin's Doubts About Design: The Darwin-Gray Correspondence of 1860," Science & Christian Belief 9 (1997): 113-27.

26Ruse, Monad to Man, 257. Bowler also states that the American school of neo-Lamarckism was founded by Cope and Hyatt (The Non-Darwinian Revolution, 73).

27H. R. Hays, Birds, Beasts, and Men: A Humanist History of Zoology (Baltimore: Penguin Books Inc., 1973), chap. 24.

28Ruse, Monad to Man; Progress (and degradation in some cases) is the topic of Ruse's book; he also explores other cultural influences upon scientific theories.

29Ruse, Monad to Man, 251-7.

30C. E. Raven, The Creator Spirit: A Survey of Christian Doctrine in the Light of Biology, Psychology and Mysticism (London: Martin Hopkinson & Co, 1927), chaps. 1, 2, and 3. Raven admired the work of the South African general, statesman, and scholar J. C. Smuts (who coined the word holism); hence Raven's emphasis on "the whole."

31Raven, The Creator Spirit, chap. 3. Raven is fascinated by Fabre's descriptions of complex insect behavior, and is of the opinion that the complexity of these behavior patterns disprove Darwin's theory of evolution.

32Ibid., chap. 2.

33F. W. Dillistone, Charles Raven: Naturalist, Historian, Theologian (London: Hodder and Stoughton, 1975); P. J. Bowler, "Evolution and the Eucharist: Bishop E. W. Barnes on science and religion in the 1920s and 1930s," British Journal of the History of Biology 31:453-67.

34J. R. Moore, The Post-Darwinian Controversies: A Study of the Protestant Struggle to Come to Terms with Darwin in Great Britain and America 1870-1900 (Cambridge: Cambridge University Press, 1979); D. N. Livingstone, Darwin's Forgotten Defenders: The Encounter Between Evangelical Theology and Evolutionary Thought (Grand Rapids: Eerdmans Publishing Co., 1987). Richard Aulie published an extensive four-part review of Moore's book in the pages of this journal (Journal of the American Scientific Affiliation 34, nos. 1, 2, 3, and 4 [1982]).

35Moore, The Post-Darwinian Controversies, 118, 120.

36Bowler reviews the work of many Lamarckian thinkers in The Eclipse of Darwinism, chaps. 4-6.

37A. Koestler, The Case of the Midwife Toad (London: Hutchison & Co., 1971). Koestler does not go so far as supporting Lamarckian schemes of inheritance, but his favorable treatment of Kammerer does stem from holistic and anti-mechanistic views of biology. See also P. J. Bowler, Evolution: The History of an Idea (Berkeley: University of California Press, rev. ed., 1989), 265-6.

38A. E. Gaissinovitch, "The Origins of Soviet Genetics and the Struggle with Lamarckism, 1922-1929," Journal of the History of Biology 13 (1980): 1-52.

39H. J. Muller, "Science in Bondage," Science 113 (1951): 25-9. Muller's work played a prominent role in the Soviet debates. His work on mutations, cited widely during these debates, champions a hard-inheritance viewpoint.

40V. N. Soyfer, Lysenko and the Tragedy of Soviet Science (New Brunswick, NJ: Rutgers University Press, 1994), reviewed by S. G. Solomon, "The Rasputin of Agronomy," NY Times Review of Books (October 2, 1994): 24. See also D. Joravsky, The Lysenko Affair (Chicago: University of Chicago Press, 1970).

41E. J. Steele, Somatic Selection and Adaptive Evolution: On the Inheritance of Acquired Characters (Toronto: Williams & Wallace, 1979). A more recent book which deals with the same topic in more detail: E. J. Steele, R. A. Lindley, and R. V. Blanden, Lamarck's Signature: How Retrogenes Are Changing Darwin's Natural Selection Paradigm (St. Leonards, NSW, Australia: Allen & Unwin, 1998).

42J. Maynard Smith, "Regenerating Lamarck," Times Literary Supplement (October 24, 1980): 1195.

43J. Cairns, J. Overbaugh and S. Miller, "The Origin of Mutants," Nature 335 (1988): 142-5.

44D. MacPhee, "Directed Evolution Reconsidered," American Scientist 81 (1993): 554-61.

45J. F. McDonald, "Macroevolution and Retroviral Elements," BioScience 40 (1990): 183-91.

46O. E. Landman, "The Inheritance of Acquired Characteristics," Annual Review of Genetics 25 (1991): 1-20; ------, "Inheritance of Acquired Characteristics," BioScience 43, no. 10 (1993): 696-704; ------, "Inheritance of Acquired Characteristics," Scientific American 266, no. 3 (1993): 150.

47Landman, 1991.

48J. Lederberg, "Genetic Approaches to Somatic Cell Variation: Summary Comment," Journal of Cellular and Comparative Physiology 52, Suppl. 1 (1958): 383-401.

49A. Novick and M. Weiner, "Enzyme Induction as an All-or-None Phenomenon," Proceedings of the National Academy of Sciences 43 (1957): 553-65.

50O. E. Landman, M.-R De Castro-Costa, and E. C. Bond, "Mechanisms of Stability and Reversions of Mass-Conversion Stable L Forms of Bacillus subtilis," 35-43 in D. Schlessinger, ed., Microbiology (Washington, DC: American Society for Microbiology, 1977).

51R. Holliday, "The Inheritance of Epigenetic Defects," Science 238 (1987): 163-70.

52W. Reik and A. Surani, eds., Genomic Imprinting (Oxford: Oxford University Press, 1997).

53L. B. Preer and J. R. Preer, "Inheritance of Infectious Elements," in Cell Biology: A Comprehensive Treatise, Vol. 1, ed. L. Goldstein and D. M. Prescott (New York: Academic Press, 1977), 319-73.

54Landman's review stands in stark contrast to the views espoused in most current college genetics textbooks which indicate that no molecular mechanism exists or can be imagined that would make the inheritance of acquired characteristics possible.

55E. Jablonka and M. J. Lamb, Epigenetic Inheritance and Evolution: The Lamarckian Dimension (New York: Oxford University Press, 1995).

56Ibid., 14.

57Mayr, The Growth of Biological Thought, 959.

58Jablonka and Lamb, Epigenetic Inheritance and Evolution, 12.

59Lynn Margulis has been very influential since the early seventies in the dissemination of this idea. For a recent review, see L. Margulis, Symbiosis in Cell Evolution: Microbial communities in the Archean and Proterozoic Eons, 2d ed. (New York: W. H. Freeman and Company, 1993).

60Hull, "Lamarck Among the Anglos," liv.

61E. J. Steele, Somatic Selection and Adaptive Evolution.

62Hull, "Lamarck Among the Anglos," liv-lvii.

63R. Dawkins, The Selfish Gene (Oxford: Oxford University Press, 1976); ------, The Extended Phenotype: The Gene as the Unit of Selection (Oxford: Oxford University Press, 1982).

64Dawkins, The Extended Phenotype, 290. Hull has discussed the similarities between memes and Lamarckian inheritance ("Lamarck Among the Anglos," lvii-lxii).

65Bowler has published a good discussion of aspects of theory formation mentioned in this paragraph in The Mendelian Revolution: The Emergence of Hereditarian Concepts in Modern Science and Society (Baltimore: The Johns Hopkins University Press, 1989), chap. 1.

66Bowler, Charles Darwin (1990), 9.