The Value of Life is an exploration of the actual and perceived importance of biological diversity for human beings and society. Stephen R. Kellert identifies ten basic values, which he describes as biologically based, inherent human tendencies that are greatly influenced and moderated by culture, learning, and experience. Drawing on 20 years of original research, he considers: the universal basis for how humans value nature differences in those values by gender, age, ethnicity, occupation, and geographic location how environment-related (...) activities affect values variation in values relating to different species how vlaues vary across cultures policy and management implications Throughout the book, Kellert argues that the preservation of biodiversity is fundamentally linked to human well-being in the largest sense as he illustrates the importance of biological diversity to the human sociocultural and psychological condition. (shrink)

Biological diversity would apparently seem the most intuitive and easily studied of all the ecological concepts. However, in practice biodiversity has suffered from great number of definitions that vary with the specific needs of the different researchers, thus making it extremely confusing as an ecological concept. In this paper, I shortly review the concept of biodiversity showing that there exists a substantial ambiguity among ecologists as far as biodiversity conceptualization and evaluation is concerned. I conclude that, due to (...) this major disagreement on its very nature, biodiversity may be defined simply as a set of multivariate summary statistics for quantifying different characteristics of community structure. (shrink)

The modern practice of biological research required the formation of a new ethics of biology, which became a synthesis of observation and experiment. The article considers the ethical aspects of modern biology from the point of view of criticism of the anthropocentric approach. A position has been put forward on the lifetime of a modern biological group as the main criterion for its place and role in the evolution of living things. The consequence of this is the need (...) to form an attitude towards biodiversity as a one-time and equal coexistence of diverse groups of representatives of wildlife. A conceptual connection is proposed between the new ethics of biology and the classical ethical construction – the "golden rule" of ethics, and the ethics of naturalistic biology, which is inextricably linked with it, coming from the ethics of science of Goethe and Meyen. The proposed ethical concept of biology includes several elements, called "principles" by the author, which together cover all aspects of the ethics of biological research. These are the principles: 1. Biological diversity as the basis of biological "equality". 2. "Watch no touch" – look, do not touch – the ethics of "virtual experiment". 3. "Ethical means accurate" – adherence to ethically "pure" approaches to an object as a condition for obtaining accurate information about a living object. (shrink)

Aristotle’s biology is based on his method of division of animal kinds by multiple differentiae. This results in complex clusters of non-subordinate terms, between which Aristotle seeks to establish universal correlations. The form of these, however, does not correspond to that prescribed by his theory of syllogism. Mereological relations between terms are not linear and quantification is far more complex than the distinction between universal and particular propositions. Thus the axiomatisation of Aristotle’s biology requires a tool designed for analysing such (...) complex universal correlations into valid syllogistic premises. Prosleptic-like premises turn out to be the solution outlined by Aristotle. They make it possible to handle both the logic of consequence which translates from and into mereological relations between term clusters, and the complex quantification required by division based on multiple differentiæ, through the instantiation of a variable ideally consisting of indivisible groups of animals. (shrink)

Abstract Benefit sharing as envisaged by the 1992 Convention on Biological Diversity (CBD) is a relatively new idea in international law. Within the context of non-human biological resources, it aims to guarantee the conservation of biodiversity and its sustainable use by ensuring that its custodians are adequately rewarded for its preservation. Prior to the adoption of the CBD, access to biological resources was frequently regarded as a free-for-all. Bioprospectors were able to take resources out of their (...) natural habitat and develop commercial products without sharing benefits with states or local communities. This paper asks how CBD-style benefit-sharing fits into debates of justice. It is argued that the CBD is an example of a set of social rules designed to increase social utility. It is also argued that a common heritage of humankind principle with inbuilt benefit-sharing mechanisms would be preferable to assigning bureaucratic property rights to non-human biological resources. However, as long as the international economic order is characterized by serious distributive injustices, as reflected in the enormous poverty-related death toll in developing countries, any morally acceptable means toward redressing the balance in favor of the disadvantaged has to be welcomed. By legislating for a system of justice-in-exchange covering nonhuman biological resources in preference to a free-for-all situation, the CBD provides a small step forward in redressing the distributive justice balance. It therefore presents just legislation sensitive to the international relations context in the 21st century. (shrink)

Graphical AbstractUsing the indices δ+ and δ* for assessing phylogenetic diversity may lead to spurious results and interpretations; it can bias recommendations for conservation and lead to inappropriate management decisions. Therefore these indices should be avoided and other indices based on quadratic entropy (Qδ+ and Q) should be used instead.

Aesthetic value is included in virtually all accounts of the values of biodiversity, but this value is still incompletely understood. Here I offer an account of the aesthetics of biodiversity based on the understanding of aesthetics developed by Immanuel Kant. The claim of this analysis is that while individual organisms may be considered beautiful, biodiversity as a whole is sublime. This distinction poses challenges and opportunities for those who manage lands for biodiversity value. Comparison to managing art museums and wine (...) cellars and a new vision for the role of systematics and taxonomy offer some insight into the management of the sublime aspects of biodiversity. (shrink)

This paper attempts to assess and evaluate some of the economic implications of the Convention on Biological Diversity. After outlining the main principles and the scope of this Convention, the following issues are addressed: the determination of the 'optimal' level of biodiversity loss, the meaning of incremental costs, and monetary evaluation problems of ecological resources and the problems it poses for the funding mechanism. The paper concludes with a discussion of the issues of commercialisation and access to genetic (...) resources. (shrink)

With the advent of synthetic biology, scientists are increasingly relying on digital sequence information, instead of physical genetic resources. This article examines the potential impact of this shift on the access and benefit-sharing (ABS) regime of the Convention on Biological Diversity (CBD) and the Nagoya Protocol. These treaties require benefit-sharing with the owners of genetic resources. However, whether “genetic resources” include digital sequence information is unsettled. The CBD conceives genetic resources as genetic material containing functional units of heredity. (...) “Material” implies tangibility, and for some scholars, “functional units of heredity,” undefined in both treaties, mean full-coding sequences. This article argues that digital sequence information obtained from physical genetic resources, full-coding or not, should be treated as genetic resources. Literal construction of the CBD risks eroding its usefulness and the ABS regime. This is because through bioinformatics, sequence information can easily be obtained from genetic resources for utilization, without physically moving them or concluding ABS agreement with owners. The CBD must evolve with scientific progress also because sequence functionality depends on the state of knowledge. These arguments are vindicated by domestic ABS laws equating genetic information with genetic resources; Nagoya Protocol provisions deeming research exploiting the genetic composition of genetic resources as utilization of genetic resources; and CBD provisions requiring the sharing of benefits from the utilization of genetic resources. Moreover, treaty interpretation and case law demand that generic, scientific terms, such as “genetic resources” and “functional units of heredity” be interpreted in an evolutionary manner to capture scientific developments. (shrink)

Economic markets are not morally free zones. Contrary to popular misconceptions, market functioning rests on the ethical principles of fairness and voluntariness. This ethical foundation can be traced back at least to moral philosopher Adam Smith, one of the founders of modern economics. In the inconspicuous form of microeconomic axioms, these moral foundations are preserved. Thus, virtually all “neo-classic” economic concepts presuppose a market ethics of fairness and voluntariness. In a world of pervasive uncertainty on the long-term development of the (...) human-environment interaction, the protection of the global life-support systems is an important test case for the scope of the ethical content of market ethics. We review risk protection strategies in the face of this uncertainty that are (i) based on the insurance effect of biological diversity, and (ii) that employ a safe minimum standard (SMS). Because the fairness principle of market ethics requires that economic agents who cause “external” costs must, at least, compensate those who are burdened with these costs, the interests of future generations have to be included in responsible economic decision-making. The market and market ethics approach is applied to the analysis of a SMS for biological diversity, and to the inherent problems of such an approach. At the microeconomic level of individual decision-making, an unconditional protection is supported by market ethics neither for the putative interests of future generations nor for biological diversity: Poor people who struggle to cover their basic needs cannot not be required to care for biological diversity. In all other cases, the protection of biological diversity in favour of future generations is supported—if costs are not “unacceptably high”. At which cost level this point is approached, market ethics is not designed to decide. (shrink)

Defining and measuring biodiversity is an important research area in biology, with very interesting theoretical and applied aspects. Numerous definitions have been proposed, and these definitions of biodiversity influence how it is measured. From the still commonly used measure of species diversity, through higher taxon diversity, molecular measures, ecological measures and indicator taxa, these measures have as their fundamental shortcoming the lack of an explicit consideration of the evolutionary context represented by phylogenies. Attempts have been made to incorporate (...) phylogenetic considerations into measuring biodiversity, but more hypothesis‐driven research needs to be done. A specific case study is presented of how this added emphasis on phylogeny‐based biodiversity measurement can influence the way in which research is directed and hypotheses are generated. The elucidation of the relationship of biodiversity to ecosystem functioning is a very timely concern with the unarguable loss of biodiversity this planet is experiencing, whichever way biodiversity is measured. (shrink)

This paper reviews the location of Responsible Research and Innovation approaches within the access and benefit sharing policy spaces of the Convention on Biological Diversity and Nagoya Protocol. We describe how a range of dialogues on ethical research practices found a home, almost inadvertently, within the ABS policy process. However, more recent RRI dialogues around emerging technologies have not been similarly absorbed into ABS policy, due in part to the original framing of ABS and associated definitional and scope (...) issues. Consideration is given to the challenges posed to these policy processes by the transformative and rapid nature of scientific and technological change today, including the emerging field of synthetic biology. Drawing on experiences from regulating ABS, we emphasize that the integration of RRI into policies for new, emerging, or poorly understood activities such as synthetic biology faces deficiencies such as limits to government capacity, jurisdictional confusion, shortages in funds, and an absence of strategic approaches. We conclude that a coordinated combination of diverse policy processes within the CBD might provide an invaluable space for RRI dialogues on social justice, sustainability, biosafety, and other issues raised by emerging technologies. (shrink)

Traditional diversity measures such as the Shannon entropy are generally computed from the species' relative abundance vector of a given community to the exclusion of species' absolute abundances. In this paper, I first mention some examples where the total information content associated with a given community may be more adequate than Shannon's average information content for a better understanding of ecosystem functioning. Next, I propose a parametric measure of statistical information that contains both Shannon's entropy and total information content (...) as special cases of this more general function. (shrink)

The increasing problem of bioinvasion (the mixing up of natural species characterising the planet's local ecosystems due to globalisation) is investigated as an example of an ecosemiotic problematic. One concern is the scarcity of scientific knowledge about long term ecological and evolutionary consequences of invading species. It is argued that a natural science conception of the ecology of bioinvasion should be supplemented with an ecosemiotic understanding of the significance of these problems in relation to human culture, the question of cultural (...) diversity, and what it means to be indigenous or foreign. Bioinvasion, extinction of native species, and overall decrease in biodiversity, may go along with decreased cultural diversity; as when the loss of local agricultural traditions lead to genetic erosion. There are possible ecosemiotic parallels between language extinction and species extinction, both being related to globalisation. It is argued that the case of bioinvasion reveals the existence of two kinds of ecosemiotic contingency, (1) evolutionary openended and partly random generation of new species and extinction of old ones; (2) the historicity of culture in general and "culture's nature" specifically in the demarcation of a set of landscapes characteristic to a particular nation and piece of human history. (shrink)

Este trabalho propõe uma reflexão em torno da biodiversidade, a partir da crítica à política de conservação da diversidade biológica, estabelecida pela Convenção sobre Biodiversidade, considerando que ela se encontra impregnada de uma lógica utilitária e econômica. Mesmo reconhecendo os efeitos dos saberes e práticas das comunidades tradicionais como forma de manejo sustentável da biodiversidade, ela é omissa em relação à dimensão simbólica e espiritual presente nas cosmologias indígenas e seu papel conservacionista. A abordagem proposta aqui foi norteada por uma (...) análise da dualidade entre animalidade e humanidade, através de um breve exame de cosmologias indígenas sul-americanas e reflexões filosóficas. A partir de alguns fragmentos de narrativas cosmológicas procurou-se mostrar que as fronteiras entre animalidade e humanidade desaparecem. A tentativa de construir um diálogo entre cosmologias indígenas e reflexões filosóficas teve o intuito de conduzir a análise para o campo religioso da relação com o divino, como experiência de imanência. Palavras-chave: biodiversidade; cosmologias indígenas; animalidade.This work discusses biological diversity through a criticism of the biological diversity conservation policy established by the Convention of Biological Diversity, viewed here as impregnated with a utilitarian and economical logic. Although this policy recognizes the knowledge and practices of traditional communities as a tool for the sustainable management of biological diversity, it ignores the spiritual and symbolic dimension of the indigenous cosmologies and its conservationist role. The approach proposed here was guided by an analysis of the duality between animality and humanity, involving a brief examination of South American indigenous cosmologies and philosophical reflections. Through the study of a few fragments of cosmological narratives it is showed that the boundaries between animality and humanity disappear. The attempt to build a dialogue between indigenous cosmologies and philosophical reflections aimed at placing the analysis in the field of the relationship with the divine, as an immanent experience. Key words: biodiversity; indigenous cosmologies; animality. (shrink)

The increasing problem of bioinvasion (the mixing up of natural species characterising the planet's local ecosystems due to globalisation) is investigated as an example of an ecosemiotic problematic. One concern is the scarcity of scientific knowledge about long term ecological and evolutionary consequences of invading species. It is argued that a natural science conception of the ecology of bioinvasion should be supplemented with an ecosemiotic understanding of the significance of these problems in relation to human culture, the question of cultural (...) diversity, and what it means to be indigenous or foreign. Bioinvasion, extinction of native species, and overall decrease in biodiversity, may go along with decreased cultural diversity; as when the loss of local agricultural traditions lead to genetic erosion. There are possible ecosemiotic parallels between language extinction and species extinction, both being related to globalisation. It is argued that the case of bioinvasion reveals the existence of two kinds of ecosemiotic contingency, (1) evolutionary openended and partly random generation of new species and extinction of old ones; (2) the historicity of culture in general and "culture's nature" specifically in the demarcation of a set of landscapes characteristic to a particular nation and piece of human history. (shrink)

As a sort of intellectual provocation and as a lateral thinking strategy for creativity, this chapter seeks to determine what the study of the dynamics of biodiversity can offer linguists. In recent years, the analogical equation "language = biological species" has become more widespread as a metaphorical source for conceptual renovation, and, at the same time, as a justification for the defense of language diversity. Language diversity would be protected in a way similar to the mobilization that (...) has taken place to protect endangered species. Nevertheless, one must be careful when uncritically transferring conceptualizations and theoretical frameworks from one field to another, since obviously, these two phenomena are quite different in the real world. The dialogue with bioecologists starts by asking about the formation of diversity, i.e., about specialization. Here, one can observe the similarity between the processes of linguistic and genetic fragmentation, in the sense that both phenomena have a (socio)geographical basis for dispersion and consequently, for the loss of their original compact nature and their intercommunication. The self-organizing and creative properties of human beings favor the development of specific varieties for each subset, varieties that continue to evolve constantly, through the unceasing "languaging" of humanity. Regarding the continuity of species or languages, one can also observe the decisive role of intragroup relations. The staying power of linguistic varieties will increase in direct proportion to the intensity of the relationship among the components of the subset. On the other hand, if exotic elements are introduced, especially if these elements are aggressive in nature, the alteration of the ecological niche may turn out to be fatal for the continuity of the previously existing forms. This suggests to us the need to make an in-depth study of what the minimal contextual conditions would be so that a set linguistic group could be assured a sustainable continuity within a framework of linguistic contact. What type of minimum (socio-)ecological niche would a language have to have if we wished to ensure its habitual reproduction? A proposal is made here to explore the ideas of "exclusive functions" and "non-hierarchical functional distribution" for codes in situations where there is high contact and a danger of disuse. As regards change, this phenomenon is seen as an inherent element in the tendency of life to create new developments, which may or not be accompanied by an adaptation to changing environmental conditions. It is pointed out that, similar to what happens in biology, much of linguistic innovation stems from a systemically reorganized mixture of solutions from different codes. An important research question would be, however, to determine why some of these innovations disappear and others survive and extend throughout the community. The big question mark, as Mufwene points out, is, then how to manage to understand how "the evolution of language proceeds by naturally selecting from among the competing alternatives available through the idiolects of individual speakers". Extinction, whether it be of languages or of species, is caused in most cases "by a combination of demographic processes and environmental changes", as Brown points out. Thus, the environment plays a fundamental role in the direction of evolution, since the "the survival of the fittest is, in actuality, the survival of those who fit into the context (Allen and Hoekstra)". This allows us to see the great degree of importance of political-economic contexts in the case of languages. In the same way, migratory movements are also one of the major variables determining the extinction of biodiversity and language diversity. Species and habitat form the basic unit of existence, and this is the major point of departure for understanding the problem of the preservation and recovery of species or languages. Given the increase in the degree of linguistic contact, the continuity of language diversity depends on determining, as exactly as possible, as Prigogine, the physicist, would say, what precise conditions of imbalance may prove to be stable. The great challenge is not so much avoiding contact but managing it. And "restorative ecology" can also be of help to us here. Being able to reach sustainable solutions for language diversity implies a profound knowledge of the dynamics for determining the ways in which language is used in contact situations. The general conclusion is that linguistics is still terminologically and conceptually ill prepared to deal with the dynamic character of human languages. The world and our objects must be conceived of as elements in a state of flux, as changing systems in an unstable equilibrium. With respect to language policy, it would be necessary to make an effort to manage to establish some general principles regarding the linguistic organization of the human species that would make it possible for local linguistic diversity and communication on a planetary scale, which must necessarily take place, to be compatible with each other. To succeed, it will be necessary to continue promoting an autonomous socio-ecological perspective devoted to the comprehension of language phenomena. Such a perspective would be based on a paradigm of complexity, and would, at the same time, place human beings at the center of its theoretical underpinnings. (shrink)

1 The Zero-Force Evolutionary Law 2 Randomness, Hierarchy, and Constraint 3 Diversity 4 Complexity 5 Evidence, Predictions, and Tests 6 Philosophical Foundations 7 Implications.

A recurrent theme in the characterization of synthetic biology is the role of engineering. This theme is widespread in the accounts of scholars studying this field and the biologists working in it, in those of the biologists themselves, as well as in policy documents. The aim of this article is to open this black-box of engineering that is supposed to influence and change contemporary life sciences. Too often, both synthetic biologists and their critics assume a very narrow understanding of what (...) engineering is about, resulting in an unfruitful debate about whether synthetic biology possesses genuine engineering methodologies or not. By looking in more detail to the diversity of engineering conceptions in debates concerning synthetic biology, a richer perspective can be developed. In this article, I will examine five influential ways in which engineering is understood in these debates, namely engineering as applied science, as rational methodology, context-sensitive practice, cunning activity or design. The claim is first of all thus to argue that engineering must not be seen as something stable or characterized by a fixed essence. It rather has multiple meanings and interpretations. Secondly, the claim is that most of the debates on synthetic biology cannot be indifferent towards the question which conception of engineering is at play, since the specific questions and concerns that pop up depend to a great extent on the precise conception of engineering one has in account. Many of the existing debates around synthetic biology can thus be reinterpreted and readdressed once one is aware of which conception of engineering is at play. (shrink)

Explanation in biology has long been characterized as being very different from explanation in other scientific disciplines, very much so from explanation in physics. One of the reasons was the existence in biology of explanation types that were unheard of in the physical sciences: teleological explanations (e.g. Hull 1974), evolutionary explanations (e.g. Mayr 1988), or even functional explanations (e.g. Neander 1991). More recently, and owing much to the rise of molecular biology, biological explanations have been depicted as mechanisms (e.g; (...) Machamer, Darden and Craver 2000). The aim of this volume is to shed some new light on the diversity of explanation types in biology. What are the different types of explanation that occur in biology? Are these types of explanation specific to particular sub-disciplines of biology, or to particular types of problems across biology? How do they relate to each another? Do they compete with one another for answering the same questions? Or do they complement each other, providing insights to different questions? What are the reasons for such diversity? Can this diversity be overcome by a broader unifying model of explanation or is it more profound and irreducible? Why? This volume aims at making sense of this diversity of types of explanations that are found in biology, of their relationship with one another. After all, explanation in biology may prove not only different from explanation in the physical sciences, but also much more diverse than originally anticipated. (shrink)

Many enzymes are inhibited by their own substrates, leading to velocity curves that rise to a maximum and then descend as the substrate concentration increases. Substrate inhibition is often regarded as a biochemical oddity and experimental annoyance. We show, using several case studies, that substrate inhibition often has important biological functions. In each case we discuss, the biological significance is different. Substrate inhibition of tyrosine hydroxylase results in a steady synthesis of dopamine despite large fluctuations in tyrosine due (...) to meals. Substrate inhibition of acetylcholinesterase enhances the neural signal and allows rapid signal termination. Substrate inhibition of phosphofructokinase ensures that resources are not devoted to manufacturing ATP when it is plentiful. In folate metabolism, substrate inhibition maintains reactions rates in the face of substantial folate deprivation. Substrate inhibition of DNA methyltransferase serves to faithfully copy DNA methylation patterns when cells divide while preventing de novo methylation of methyl‐free promoter regions. (shrink)

Biology arises from the crowded molecular environment of the cell, rendering it a challenge to understand biological pathways based on the reductionist, low‐concentration in vitro conditions generally employed for mechanistic studies. Recent evidence suggests that low‐affinity interactions between cellular biopolymers abound, with still poorly defined effects on the complex interaction networks that lead to the emergent properties and plasticity of life. Mass‐action considerations are used here to underscore that the sheer number of weak interactions expected from the complex mixture (...) of cellular components significantly shapes biological pathway specificity. In particular, on‐pathway—i.e., “functional”—become those interactions thermodynamically and kinetically stable enough to survive the incessant onslaught of the many off‐pathway (“nonfunctional”) interactions. Consequently, to better understand the molecular biology of the cell a further paradigm shift is needed toward mechanistic experimental and computational approaches that probe intracellular diversity and complexity more directly. Also see the video abstract here https://youtu.be/T19X_zYaBzg. (shrink)

Given its subject matter, biological psychiatry is uniquely poised to lead STEM DEI initiatives related to disability. Drawing on literatures in science, philosophy, psychiatry, and disability studies, we outline how that leadership might be undertaken. We first review existing opportunities for the advancement of DEI in biological psychiatry around axes of gender and race. We then explore the expansion of biological psychiatry’s DEI efforts to disability, especially along the lines of representation and access, community accountability, first person (...) testimony, and revised theoretical frameworks for pathology. We close with concrete recommendations for scholarship and practice going forward. By tackling head-on the challenge of disability inclusion, biological psychiatry has the opportunity to be a force of transformation in the biological sciences and beyond. (shrink)

Explores the development of the ideas of evolutionary biology, particularly as affected by the increasing understanding of genetics and of the chemical basis of inheritance.

In this article, I am concerned with the public engagements of Julian Huxley, Lancelot Hogben, and J. B. S. Haldane. I analyze how they used the new insights into the genetics of heredity to argue against any biological foundations for antidemocratic ideologies, be it Nazism, Stalinism, or the British laissez-faire and class system. The most striking fact—considering the abuse of biological knowledge they contested—is that these biologists presented genetics itself as inherently democratic. Arguing from genetics, they developed an (...) understanding of diversity that cuts across divisions of race, class, or gender. Human diversity rightly understood was advantageous for societal progress. Huxley, Hogben, and Haldane did not hold identical political ideals, but they all argued for democratic reforms and increased planning geared toward greater social equality, and they did so under the label of scientific humanism. Huxley took issue with the notion that evolutionary history does not carry any moral lessons for human societies. Rather than being its antithesis, evolution was the basis of human sociality. In fact, the entire future progress of individuals and communities toward a democratic world order needed to be founded on the cosmic principles of evolution—a process that had to be guided by the biological expert with a strong sense of social responsibility. (shrink)

This paper argues both that the decentralized and democratic context in the United States prior to World War II encouraged the development of diverse approaches, programs, and institutional supports for the biological sciences, and that the resulting pluralism is consistent with the complex and messy ways that science is used in a democratic society. This is not a claim that only U.S. science experiences such diversity, nor that the way science plays out in our American form of modified (...) constitutional democracy, are unique. Rather, my intention is to underline the particular character of the diversity and its implications for science and to begin further discussion of this phenomenon. I challenge others to pursue comparative analysis for other places and times, so that we can begin to explore more deeply what meaning this diversity — or the lack thereof - holds for science more generally. (shrink)

The Krüppel‐like factors (KLFs) comprise a family of evolutionarily conserved zinc finger transcription factors that regulate numerous biological processes including proliferation, differentiation, development and apoptosis. KLF4 and KLF5 are two closely related members of this family and are both highly expressed in epithelial tissues. In the intestinal epithelium, KLF4 is expressed in terminally differentiated epithelial cells at the villus borders of the mucosa and inhibits cell growth, while KLF5 is expressed in proliferating epithelial cells at the base of the (...) intestinal crypts and promotes cell growth. KLF4 and KLF5 respond to a myriad of external stress stimuli and are likely involved in restoring cellular homeostasis following exposure to stressors. Confirming their importance in maintaining tissue integrity, KLF4 and KLF5 are both dysregulated in various types of cancer. Here we review the recent advances in defining the physiological and pathobiological roles of KLF4 and KLF5, focusing on their functions in the intestinal epithelium. BioEssays 29:549–557, 2007. © 2007 Wiley Periodicals, Inc. (shrink)