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1.
Richard L. Mayden and Kevin de Queiroz have devised and developed ‘a hierarchy of species concepts’ and ‘a unified species concept’, respectively. Although their integrated frameworks of species concepts are rather different as to how to integrate the diverse modern concepts of species, the end result is that they are likely to agree on species recognition in nature, because they virtually share the same major components (i.e. evolutionary or lineage concept of species; same way of delimiting species), and have the same important consequences. Both the hierarchical and unified frameworks, however, are interpreted to have shortcoming regarding the way of integrating the modern species concepts. I reformulate these ideas into a framework of species concepts as follows: It treats the idea of species as population‐level evolutionary lineages (sensu Wiley 1978 ) as the concept for species category, and it adopts the contingent biological properties of species (e.g. internal reproductive isolation, diagnosability, monophyly) as operational criteria in delimiting species. I also suggest that existing and revised versions of the integrated framework of species concepts all are not new species concepts, but versions of the evolutionary species concept, because they treat the evolutionary (or lineage) species concept as the concept for species category.  相似文献   

2.
A major issue in philosophical debates on the species problem concerns the opposition between two seemingly incompatible views of the metaphysics of species: the view that species are individuals and the view that species are natural kinds. In two recent papers in this journal, Olivier Rieppel suggested that this opposition is much less deep than it seems at first sight. Rieppel used a recently developed philosophical account of natural kindhood, namely Richard Boyd's "homeostatic property cluster" theory, to argue that every species taxon can be conceived of as an individual that constitutes the single member of its own specific natural kind. In this paper I criticize Rieppel's approach and argue that it does not deliver what it is supposed to, namely an account of species as kinds about which generalized statements can be made.  相似文献   

3.
What's in a species? The multiple connotations of the question tend to lack simple answers, and not surprisingly so. For example, speciation is a gradual process. Can we say when exactly a child has become an adult? We have precocious youngsters and late bloomers, and often, adults are in some ways childish. There are many triggers for and routes to adolescence. All this holds for speciation, and delimiting species can therefore be a tricky task. Recently, the field of integrative taxonomy has emerged—species delimitation based on multiple sources of evidence. Given that we expect species to exhibit peculiarities in at least one or a few aspects, might it be their alleles of a gene, their morphology, chemistry, behaviour, ecology, reproductive compatibility, or whatever, investigating not just one but several of these aspects makes it more likely that we capture such peculiarities. If the same pattern is found multiply, we talk about agreement among disciplines, and species delimitation is easy. But what if different disciplines tell different stories? Such disagreement makes species delimitation more difficult but is also an opportunity for evolutionary biology (Schlick‐Steiner et al. 2010). In this issue of Molecular Ecology, Andújar et al. (2014) present a comprehensive integrative‐taxonomic case study of Mesocarabus ground beetles including nomenclatural consequences. They resolve extensive disagreement among disciplines by invoking evolutionary explanations, and the process of conflict resolution thus advances knowledge on species boundaries and evolutionary processes simultaneously.  相似文献   

4.
Herein, I review existing criticisms of the field of invasion biology. Firstly, I identifiy problems of conceptual weaknesses, including disagreements regarding: (i) definitions of invasive, impact, and pristine conditions, and (ii) ecological assumptions such as species equilibrium, niche saturation, and climax communities. Secondly, I discuss methodological problems include the misuse of correlations, biases in impact reviews and risk assessment, and difficulties in predicting the effects of species introductions or eradications. Finally, I analyse the social conflict regarding invasive species management and differences in moral and philosophical foundations. I discuss the recent emergence of alternatives to traditional invasion biology approaches, including the concept of novel ecosystems, conciliation biology, and compassionate conservation. Understanding different value systems will be the first step to reconciling the different perspectives related to this controversial topic.  相似文献   

5.
Species‐level taxonomy derives from empirical sources (data and techniques) that assess the existence of spatiotemporal evolutionary lineages via various species “concepts.” These concepts determine if observed lineages are independent given a particular methodology and ontology, which relates the metaphysical species concept to what “kind” of thing a species is in reality. Often, species concepts fail to link epistemology back to ontology. This lack of coherence is in part responsible for the persistence of the subspecies rank, which in modern usage often functions as a placeholder between the evolutionary events of divergence or collapse of incipient species. Thus, prospective events like lineages merging or diverging require information from unknowable future information. This is also conditioned on evidence that the lineage already has a detectably distinct evolutionary history. Ranking these lineages as subspecies can seem attractive given that many lineages do not exhibit intrinsic reproductive isolation. We argue that using subspecies is indefensible on philosophical and empirical grounds. Ontologically, the rank of subspecies is either identical to that of species or undefined in the context of evolutionary lineages representing spatiotemporally defined individuals. Some species concepts more inclined to consider subspecies, like the Biological Species Concept, are disconnected from evolutionary ontology and do not consider genealogy. Even if ontology is ignored, methods addressing reproductive isolation are often indirect and fail to capture the range of scenarios linking gene flow to species identity over space and time. The use of subspecies and reliance on reproductive isolation as a basis for an operational species concept can also conflict with ethical issues governing the protection of species. We provide a way forward for recognizing and naming species that links theoretical and operational species concepts regardless of the magnitude of reproductive isolation.  相似文献   

6.
Finding out why we have beliefs and desires is important for a thorough understanding of the nature of our minds (and those of other animals). It is therefore unsurprising that several accounts have been presented that are meant to answer this question. At least in the philosophical literature, the most widely accepted of these are due to Kim Sterelny and Peter Godfrey-Smith, who argue that beliefs and desires evolved due to their enabling us to be behaviourally flexible in a way that reflexes do not—which, they claim, is beneficial in epistemically complex environments. However, as I try to make clear in this paper, upon closer consideration, this kind of account turns out to be theoretically implausible. In the main, this is because it fails to give due credit to the powers of reflex-driven organisms, which can in fact be just as flexible in their behaviour as ones that are belief/desire-driven. In order to improve on this account, I therefore propose that beliefs and desires evolved, not due to their enabling us to do something completely different from what reflexive organisms can do, but rather due to their enabling us to do the same things better. Specifically, I argue that beliefs and desires evolved for making the generation of behaviour more efficient, since they can simplify the necessary cognitive labour considerably. I end by considering various implications of this account.  相似文献   

7.
Santa Rosalia revisited: Why are there so many species of bacteria?   总被引:18,自引:0,他引:18  
The diversity of bacteria in the world is very poorly known. Usually less than one percent of the bacteria from natural communities can be grown in the laboratory. This has caused us to underestimate bacterial diversity and biased our view of bacterial communities. The tools are now available to estimate the number of bacterial species in a community and to estimate the difference between communities. Using what data are available, I have estimated that thirty grams of forest soil contains over half a million species. The species difference between related communities suggests that the number of species of bacteria may be more than a thousand million. I suppose that the explanation for such a large number of bacterial species is simply that speciation in bacteria is easy and extinction difficult, giving a rate of speciation higher than the rate of extinction, leading to an ever increasing number of species over time. The idea that speciation is easy is justified from the results of recent experimental work in bacterial evolution.  相似文献   

8.
Understanding how species interactions influence their distribution and evolution is a fundamental question in evolutionary biology. Theory suggests that asymmetric reproductive interference, in which one species induces higher reproductive costs on another species, may be more important in delimiting species boundaries than interspecific competition over resources. However, the underlying mechanisms of such asymmetry remain unclear. Here, we test whether differences in within‐species reproductive costs determine the between‐species asymmetry of costs using three allopatric Drosophila species belonging to the melanogaster subgroup. Our results support this hypothesis, especially in a pair of insular species. Males of one species that induce costs to their conspecific females led to a 5‐fold increase of heterospecific females mortality with dead flies bearing spectacular large melanized wounds on their genitalia. Males of the other species were harmful neither to their conspecific nor heterospecific females. Comparative studies of within‐species reproductive costs may therefore be a valuable tool for predicting between‐species interactions and community structures.  相似文献   

9.
Since the 1970s, there has been a tremendous amount of literature on Ghiselin's proposal that “species are individuals”. After recalling the origins and stakes of this thesis in contemporary evolutionary theory, I show that it can also be found in the writings of the French naturalist Buffon in the 18th Century. Although Buffon did not have the conception that one species could be derived from another, there is an interesting similarity between the modern argument and that of Buffon regarding the “individuality of species’. The analogy is strong enough to force us to recognize that genuine evolutionary (or Darwinian) questions might be of secondary importance in the discussion. In consequence, the third section of the paper proposes an alternative schema for the “logical structure” of the Darwinian concept of species. Darwin distinguished the problem of the designation of a concrete species, and the problem of its signification of species within his theory of descent? The resulting notion of species involves a logical structure based on the fusion of the logical operations of classification and ordering. The difficulty — and interest — is that this interpretation of species does not entail any precise operational definition of species; it can only tell us what the ultimate signification of classification is within the theory of descent with modification through natural selection.  相似文献   

10.
There is no sharp dividing line between science and philosophy, but philosophical problems tend to have three special features. First, they tend to concern large frameworks rather than specific questions within the framework. Second, they are questions for which there is no generally accepted method of solution. And third they tend to involve conceptual issues. For these reasons a philosophical problem such as the nature of life can become a scientific problem if it is put into a shape where it admits of scientific resolution. Philosophy in the 20th century was characterized by a concern with logic and language, which is markedly different from the concerns of earlier centuries of philosophy. However, it shared with the European philosophical tradition since the 17th century an excessive concern with issues in the theory of knowledge and with scepticism. As the century ends, we can see that scepticism no longer occupies centre stage, and this enables us to have a more constructive approach to philosophical problems than was possible for earlier generations. This situation is somewhat analogous to the shift from the sceptical concerns of Socrates and Plato to the constructive philosophical enterprise of Aristotle. With that in mind, we can discuss the prospects for the following six philosophical areas: (1) the traditional mind-body problem; (ii) the philosophy of mind and cognitive science; (iii) the philosophy of language; (iv) the philosophy of society; (v) ethics and practical reasons; (vi) the philosophy of science. The general theme of these investigations, I believe, is that the appraisal of the true significance of issues in the philosophy of knowledge enables us to have a more constructive account of various other philosophical problems than has typically been possible for the past three centuries.  相似文献   

11.
Conservation managers are in the unenviable position of trying to conserve and restore biodiversity, without having a definitive timeframe to restore it to. Currently, managers around the world focus on various timeframes from recent to historical, but without a definitive target, countless conservation problems arise. Managers need to determine what constitutes a native species, which species to reintroduce, whether selective breeding should be implemented to resurrect supposedly extinct organisms, targets on population levels, whether assisted migration should be employed when climate change alters the environmental envelope of a species surrounded by human-altered landscapes, and how to manage for stochasticity and evolutionary processes. Without having definitive goals to target, these issues are difficult/impossible to address. It is only by discussing these important issues that some consensus will be attained that allow us to stop responding to crises and start predicting the future of biodiversity and plan and respond accordingly.  相似文献   

12.
The history of ecology and evolutionary biology is rife with attempts to define and delimit species. However, there has been confusion between concepts and criteria, which has led to discussion, debate, and conflict, eventually leading to lack of consistency in delimitation. Here, we provide a broad review of species concepts, a clarification of category versus concept, an account of the general lineage concept (GLC), and finally a way forward for species discovery and delimitation. Historically, species were considered as varieties bound together by reproduction. After over 200 years of uncertainty, Mayr attempted to bring coherence to the definition of species through the biological species concept (BSC). This has, however, received much criticism, and the last half century has spawned at least 20 other concepts. A central philosophical problem is that concepts treat species as ‘individuals’ while the criteria for categorization treats them as ‘classes’. While not getting away from this problem entirely, the GLC attempts to provide a framework where lineage divergence is influenced by a number of different factors (and correlated to different traits) which relate to the different species concepts. We also introduce an ‘inclusive’ probabilistic approach for understanding and delimiting species. Finally, we provide a Wallacean (geography related) approach to the Linnaean problem of identifying and delimiting species, particularly for cases of allopatric divergence, and map this to the GLC. Going one step further, we take a morphometric terrain approach to visualizing and understanding differences between lineages. In summary, we argue that while generalized frameworks may work well for concepts of what species are, plurality and ‘inclusive’ probabilistic approaches may work best for delimitation.  相似文献   

13.
The ability to ascertain abundance and spatial extent of a nascent population of a non-native species can inform management decisions. Following initial detection, delimiting surveys, which involve the use of a finer network of samples around the focal point of a newly detected colony, are often used to quantify colony size, spatial extent, and the location of the population core. Despite the widespread use of pheromone-baited traps in delimitation surveys to manage invading populations of Lymantria dispar (L.) in North America, there has been no prior comprehensive attempt to analytically determine the adequacy of these surveys. We used data from 2,190 delimiting grids collected from 2000 to 2010 in the United States to quantify the information gained from delimiting surveys. The use of delimiting surveys revealed that ≈53 % of populations of low initial abundance persisted as detectable populations in the following year; however, when trap data from delimiting surveys were excluded, only ≈16 % of these low density populations were detected in the following year. Measurements of abundance and spatial extent of a detected population were affected by the increased use of delimiting traps after accounting for initial abundance, the distance from an infested area, and colony area. The use of delimiting traps had a lesser effect on the estimation of the spatial location of the population core, indicating that initial detection of a population often reflects the population core. The need to prioritize resources in efforts to manage non-native species is paramount, and early detection is a key in invasive species management.  相似文献   

14.
Species delimitation is the act of identifying species‐level biological diversity. In recent years, the field has witnessed a dramatic increase in the number of methods available for delimiting species. However, most recent investigations only utilize a handful (i.e. 2–3) of the available methods, often for unstated reasons. Because the parameter space that is potentially relevant to species delimitation far exceeds the parameterization of any existing method, a given method necessarily makes a number of simplifying assumptions, any one of which could be violated in a particular system. We suggest that researchers should apply a wide range of species delimitation analyses to their data and place their trust in delimitations that are congruent across methods. Incongruence across the results from different methods is evidence of either a difference in the power to detect cryptic lineages across one or more of the approaches used to delimit species and could indicate that assumptions of one or more of the methods have been violated. In either case, the inferences drawn from species delimitation studies should be conservative, for in most contexts it is better to fail to delimit species than it is to falsely delimit entities that do not represent actual evolutionary lineages.  相似文献   

15.
Nadler SA  DE León GP 《Parasitology》2011,138(13):1688-1709
Herein we review theoretical and methodological considerations important for finding and delimiting cryptic species of parasites (species that are difficult to recognize using traditional systematic methods). Applications of molecular data in empirical investigations of cryptic species are discussed from an historical perspective, and we evaluate advantages and disadvantages of approaches that have been used to date. Developments concerning the theory and practice of species delimitation are emphasized because theory is critical to interpretation of data. The advantages and disadvantages of different molecular methodologies, including the number and kind of loci, are discussed relative to tree-based approaches for detecting and delimiting cryptic species. We conclude by discussing some implications that cryptic species have for research programmes in parasitology, emphasizing that careful attention to the theory and operational practices involved in finding, delimiting, and describing new species (including cryptic species) is essential, not only for fully characterizing parasite biodiversity and broader aspects of comparative biology such as systematics, evolution, ecology and biogeography, but to applied research efforts that strive to improve development and understanding of epidemiology, diagnostics, control and potential eradication of parasitic diseases.  相似文献   

16.
A climatic basis for microrefugia: the influence of terrain on climate   总被引:1,自引:0,他引:1  
There is compelling evidence from glacial and interglacial periods of the Quaternary of the utilization of microrefugia. Microrefugia are sites that support locally favorable climates amidst unfavorable regional climates, which allow populations of species to persist outside of their main distributions. Knowledge of the location of microrefugia has important implications for climate change research as it will influence our understanding of the spatial distribution of species through time, their patterns of genetic diversity, and potential dispersal rates in response to climate shifts. Indeed, the implications of microrefugia are profound and yet we know surprisingly little about their climatic basis; what climatic processes can support their subsistence, where they may occur, their climatic traits, and the relevance of these locations for climate change research. Here I examine the climatic basis for microrefugia and assert that the interaction between regional advective influences and local terrain influences will define the distribution and nature of microrefugia. I review the climatic processes that can support their subsistence and from this climatic basis: (1) infer traits of the spatial distribution of microrefugia and how this may change through time; (2) review assertions about their landscape position and what it can tell us about regional climates; and (3) demonstrate an approach to forecasting where microrefugia may occur in the future. This synthesis highlights the importance of landscape physiography in shaping the adaptive response of biota to climate change.  相似文献   

17.
The so-called "species problem" has plagued evolutionary biology since before Darwin's publication of the aptly titled Origin of Species. Many biologists think the problem is just a matter of semantics; others complain that it will not be solved until we have more empirical data. Yet, we don't seem to be able to escape discussing it and teaching seminars about it. In this paper, I briefly examine the main themes of the biological and philosophical literatures on the species problem, focusing on identifying common threads as well as relevant differences. I then argue two fundamental points. First, the species problem is not primarily an empirical one, but it is rather fraught with philosophical questions that require-but cannot be settled by-empirical evidence. Second, the (dis-)solution lies in explicitly adopting Wittgenstein's idea of "family resemblance" or cluster concepts, and to consider species as an example of such concepts. This solution has several attractive features, including bringing together apparently diverging themes of discussion among biologists and philosophers. The current proposal is conceptually independent (though not incompatible) with the pluralist approach to the species problem advocated by Mishler, Donoghue, Kitcher and Dupré, which implies that distinct aspects of the species question need to be emphasized depending on the goals of the researcher. From the biological literature, the concept of species that most closely matches the philosophical discussion presented here is Templeton's cohesion idea.  相似文献   

18.
By complementing two independent systematic studies published recently on the Western Australian land snail Amplirhagada, we compare levels of morphological variation in shells and genitalia with those in the mitochondrial markers cytochrome c oxidase (COI) and 16S to evaluate the utility of mtDNA markers for delimiting species. We found that penial morphology and mitochondrial divergence are generally highly consistent in delimiting species, while shells have little overall taxonomic utility in these snails. In addition to this qualitative correspondence, there is almost no overlap between intraspecific and interspecific genetic distances in COI, with the highest intraspecific and lowest interspecific distance being 6%. This value is twice the general level suggested as a DNA barcode threshold by some authors and higher than the best average found in stylommatophoran land snails. Although in Amplirhagada land snails DNA barcoding may provide meaningful information as a first‐pass approach towards species delimitation, we argue that this is due only to specific evolutionary circumstances that facilitated a long‐termed separate evolution of mitochondrial lineages along spatial patterns. However, because in general the amounts of morphological and mitochondrial differentiation of species depend on their evolutionary history and age, the mode of speciation, distributional patterns and ecological adaptations, and absence or presence of mechanisms that prevent gene flow across species limits, the applicability of DNA barcoding has to be confirmed by morphological studies for each single group anew. Based on evidence from both molecular and morphological markers, we describe six new species from the Bonaparte Archipelago and revise the taxonomy of a further two. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 165 , 337–362.  相似文献   

19.
Since Darwin's time, the question “what a species” has provoked fierce disputes and a tremendous number of publications, from short opinion papers to thick volumes. 1 The debates covered fundamental philosophical questions, such as: Do species exist at all independently of a human observer or are they just a construct of the human mind to categorize nature's organismic diversity and serve as a semantic tool in human communication about biodiversity? 2 - 4 or: Are species natural kinds (classes) or individuals that are “born” by speciation, change in course of time, and finally “die” when they go extinct or diverge into new species? 5 - 8 Also included was the problem of species as taxa (taxonomic) versus species as products of the speciation process (evolutionary). 9 More pragmatic issues arose, such as: How can we reliably delineate and delimitate species? 10 , 11 The great interest in what a species is reflects the importance of “species” as fundamental units in most fields of biology, especially evolutionary biology, ecology, and conservation. 2 , 12 - 14  相似文献   

20.
Species delimitation is a contentious topic. The genomics revolution initially brought hope that identifying and classifying species would be easier through better methods and more data, but genomics has also brought complexity and controversy to delimitation. One solution can be to collect a larger sample of individuals at a finer geographic scale. But what if taxa are rare and collecting more samples is difficult or detrimental to the organisms at hand? In this issue of Molecular Ecology Resources, Opatova et al. (2023) tackle the ambiguity of species delimitation in rare and endangered trapdoor spiders (genus Cyclocosmia). The authors propose a framework for delimiting species when samples are hard to come by, such as in these rare and cryptic spiders. The authors combine extensive genomic sampling with statistical approaches that consider both the genetic distinctiveness of each population of spiders and how much gene flow occurs between these populations. Their proposed taxonomy balances two opposing signals, structure and gene flow, to count eight lineages of Cyclocosmia, and to point the way for future taxonomic studies of the rare or difficult to obtain.  相似文献   

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