Ecomorphology or ecological morphology is the study of the relationship between the ecological role of an individual and its morphological adaptations.[1] The term "morphological" here is in the anatomical context. Both the morphology and ecology exhibited by an organism are directly or indirectly influenced by their environment, and ecomorphology aims to identify the differences [2] Current research places emphasis on linking morphology and ecological niche by measuring the performance of traits (i.e. sprint speed, bite force, etc.) associated behaviours, and fitness outcomes of the relationships.
Current ecomorphological research focuses on a functional approach and application to the science. A broadening of this field welcomes further research in the debate regarding differences between both the ecological and morphological makeup of an organism.
Development of ecomorphology
The roots of ecomorphology date back to the late 19th century.[3] Then, description and comparison of morphological form, primarily for use in avianclassification, was focal point of morphological research. However, during the 1930s and 40s morphology as a field shrank. This was likely due to the emergence of new areas of biological inquiry enabled by new techniques. The 1950s brought about not only a change in the approach of morphological studies, resulting in the development of evolutionary morphology in the form of theoretical questions, and a resurgence of interest in the field.[4]High-speed cinematography and x-ray cinematography began to allow for observations of movements of parts while electromyography allowed for observation of the integration of muscle activities. Together, these methodologies allowed morphologists to better delve into the intricacies of their study. It was then, in the 1950s and 60s, that ecologists began to use morphological measures to study evolutionary and ecological questions. This culminated in Karr and James coining the term "ecomorphology" in 1975.[5] The following year the links between vertebrate morphology and ecology were finally established creating the foundations of modern ecomorphology.[6][7]
Ecomorphology
Ecomorphology and functional morphology
Ecomorphological relationships have been demonstrated between jaw structure and the feeding biology of sunfish.
Functional morphology differs from ecomorphology in that it deals with the features arising from form at varying levels of organisation.[8] Ecomorphology, on the other hand, refers to those features which can be shown to derive from the ecology surrounding the species. In other words, functional morphology focuses heavily on the relationship between form and function whereas ecomorphology is interested in the form and the influences from which it arises. Functional morphology studies often investigate relationships between the form of Skeletal muscle and physical properties such as force generation and joint mobility.[9] This means that functional morphology experiments may be done under laboratory conditions whereas ecomorphological experiments may not. Moreover, studies of functional morphology themselves provide insufficient data upon which to make conclusions regarding environmental adaptations of a species. The data provided from these studies can, however, support and enrich the understanding of a species' ecomorphological adaptations.[3] For instance, the relationship between the organization of the jaw lever-arm system, mouth size, and jaw muscle force generation and the feeding behaviour of sunfish has been investigated.[10] Work of this variety lends scientific support to seemingly intuitive concepts. For instance, increases in mouth size correspond to an increase in prey size. However, less obvious trends also exist. The prey-size of fish does not seem to correlate so much to body size as to the characteristics of the feeding apparatus.
Behavioural studies
The work above is just one example of an ecomorphology based behavioural study. Studies of this variety are becoming increasingly important in the field. Behavioural studies interrelate functional and eco-morphology. Features such as locomotory ability in foraging birds have been shown to affect dietary preferences by studies of this type.[11] Behavioural studies are particularly common in fisheries and in studying birds.[12] Other studies attempt to relate ecomorphological findings with the dietary habits of species. Griffen and Mosblack (2011) investigated differences in diet and consumption rate as a function of gut ecomorphology.[13] Indeed, gut volume was found to correlate positively to increasing metabolic rate. Ecomorphological studies can often be used to determine to presence of parasites in a given temporospatial context as parasite presence can alter host habitat use.[14]
Other current work within ecomorphology focuses on broadening the knowledge base to allow for ecomorphological studies to incorporate a wider range of habitats, taxa, and systems. Much current work also focuses on the integration of ecomorphology with other comparative fields such as phylogenetics and ontogenetics to better understand evolutionary morphology.[15]
Applications of ecomorphology
Simplified representation of an ecological niche where A and B show the fundamental niches of species 1 and species 2 respectively. Z the realised niche of species 2 and X the niche overlap, where competition occurs among species.
An understanding of ecomorphology is necessary when investigating both the origins of and reasons for biodiversity within a species. Ecomorphology is fundamental for understanding changes in the morphology of a species in which subsets occupy different ecological niches, demonstrate different reproductive techniques, and have various sensory modalities.[15][16] Studies conducted on species with high biodiversity frequently investigate the extent to which species morphology is influenced by their ecology. Bony fishes are often used to study ecomorphology due to their long evolutionary history, high biodiversity, and multi-stage life cycle.[15] Studies on the morphological diversity of African cichlids conducted by Fryer and Iles were some of the first to demonstrate ecomorphology, . This is largely due to cichlids having great biodiversity, wide distribution, the ability to occupy various ecological niches, and obvious morphological differences.[17] Ecomorphology is also often used to study the paleohabitat of a species and/or its evolutionary morphology.
Paleohabitat determination from ecomorphology
The history of how a species has undergone morphological adaptations to better suit its ecological role can be used to draw conclusions about its paleohabitat. The morphologies of paleo-species found at a location help to make inferences about the previous appearance and properties of that habitat. Research using this approach has been widely conducted using bovidfossils due to their large skeletons and extensive species radiation.[18] Plummer and Bishop conducted a study using extant African bovids to investigate the animal’s paleoenvironment based on their habitat preference.[19] The strong correlation found between bovid phylogeny and habitat preference suggests that linking morphology and habitat is taxon dependent. Evidence also suggests that further study of the ecomorphology of previously existing habitats may be useful in determining the phylogenetic risk associated with species living in a specific habitat.[18]
Evolutionary morphology
The study of evolutionary morphology concerns changes in species morphology over time in order to become better suited to their environment.[3][16] These studies are conducted by comparing the features of species groups to provide a historical narrative of the changes in morphology observed with changes in habitat. A background history of a species features and homology must first be known before a history of evolutionary morphology can be observed. This area of biology serves only to provide a nominal explanation of evolutionary biology, as a more in depth explanation of species history is required to provide a thorough explanation of evolution within a species.
Ecomorphology versus habitat preference
Suggestions have been made that the correlations between species biodiversity and particular environments may not necessarily be due to ecomorphology, but rather a conscious decision made by species to relocate to an ecosystem to which their morphologies are better suited. However, there are currently no studies that provide concrete evidence to support this theory. Studies have been conducted to predict fish habitat preference based on body morphology, but no definitive distinction could be made between correlation and causation of fish habitat preference.[20]
Related Research Articles
In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, alters biotic interactions or opens new environmental niches. Starting with a single ancestor, this process results in the speciation and phenotypic adaptation of an array of species exhibiting different morphological and physiological traits. The prototypical example of adaptive radiation is finch speciation on the Galapagos, but examples are known from around the world.
Ecology is a branch of biology concerning the spatial and temporal patterns of the distribution and abundance of organisms, including the causes and consequences. Topics of interest include the biodiversity, distribution, biomass, and populations of organisms, as well as cooperation and competition within and between species. Ecosystems are dynamically interacting systems of organisms, the communities they make up, and the non-living components of their environment. Ecosystem processes, such as primary production, pedogenesis, nutrient cycling, and niche construction, regulate the flux of energy and matter through an environment. These processes are sustained by organisms with specific life history traits.
Cichlids are fish from the family Cichlidae in the order Cichliformes. Cichlids were traditionally classed in a suborder, the Labroidei, along with the wrasses (Labridae), in the order Perciformes, but molecular studies have contradicted this grouping. The closest living relative of cichlids is probably the convict blenny, and both families are classified in the 5th edition of Fishes of the World as the two families in the Cichliformes, part of the subseries Ovalentaria. This family is both large and diverse. At least 1,650 species have been scientifically described, making it one of the largest vertebrate families. New species are discovered annually, and many species remain undescribed. The actual number of species is therefore unknown, with estimates varying between 2,000 and 3,000.
Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, isolation and habitat area. Phytogeography is the branch of biogeography that studies the distribution of plants. Zoogeography is the branch that studies distribution of animals. Mycogeography is the branch that studies distribution of fungi, such as mushrooms.
In ecology, a biological interaction is the effect that a pair of organisms living together in a community have on each other. They can be either of the same species, or of different species. These effects may be short-term, like pollination and predation, or long-term; both often strongly influence the evolution of the species involved. A long-term interaction is called a symbiosis. Symbioses range from mutualism, beneficial to both partners, to competition, harmful to both partners. Interactions can be indirect, through intermediaries such as shared resources or common enemies. This type of relationship can be shown by net effect based on individual effects on both organisms arising out of relationship.
Sympatric speciation is the evolution of a new species from a surviving ancestral species while both continue to inhabit the same geographic region. In evolutionary biology and biogeography, sympatric and sympatry are terms referring to organisms whose ranges overlap so that they occur together at least in some places. If these organisms are closely related, such a distribution may be the result of sympatric speciation. Etymologically, sympatry is derived from the Greek roots συν ("together") and πατρίς ("homeland"). The term was coined by Edward Bagnall Poulton in 1904, who explains the derivation.
The three-spined stickleback is a fish native to most inland and coastal waters north of 30°N. It has long been a subject of scientific study for many reasons. It shows great morphological variation throughout its range, ideal for questions about evolution and population genetics. Many populations are anadromous and very tolerant of changes in salinity, a subject of interest to physiologists. It displays elaborate breeding behavior and it can be social making it a popular subject of enquiry in fish ethology and behavioral ecology. Its antipredator adaptations, host-parasite interactions, sensory physiology, reproductive physiology, and endocrinology have also been much studied. Facilitating these studies is the fact that the three-spined stickleback is easy to find in nature and easy to keep in aquaria.
In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the population during that process. Thirdly, it is a phenotypic trait or adaptive trait, with a functional role in each individual organism, that is maintained and has evolved through natural selection.
Evolutionary ecology lies at the intersection of ecology and evolutionary biology. It approaches the study of ecology in a way that explicitly considers the evolutionary histories of species and the interactions between them. Conversely, it can be seen as an approach to the study of evolution that incorporates an understanding of the interactions between the species under consideration. The main subfields of evolutionary ecology are life history evolution, sociobiology, the evolution of interspecific interactions and the evolution of biodiversity and of ecological communities.
An evolutionary radiation is an increase in taxonomic diversity that is caused by elevated rates of speciation, that may or may not be associated with an increase in morphological disparity. Radiations may affect one clade or many, and be rapid or gradual; where they are rapid, and driven by a single lineage's adaptation to their environment, they are termed adaptive radiations.
Character displacement is the phenomenon where differences among similar species whose distributions overlap geographically are accentuated in regions where the species co-occur, but are minimized or lost where the species' distributions do not overlap. This pattern results from evolutionary change driven by biological competition among species for a limited resource. The rationale for character displacement stems from the competitive exclusion principle, also called Gause's Law, which contends that to coexist in a stable environment two competing species must differ in their respective ecological niche; without differentiation, one species will eliminate or exclude the other through competition.
In biology, co-adaptation is the process by which two or more species, genes or phenotypic traits undergo adaptation as a pair or group. This occurs when two or more interacting characteristics undergo natural selection together in response to the same selective pressure or when selective pressures alter one characteristic and consecutively alter the interactive characteristic. These interacting characteristics are only beneficial when together, sometimes leading to increased interdependence. Co-adaptation and coevolution, although similar in process, are not the same; co-adaptation refers to the interactions between two units, whereas co-evolution refers to their evolutionary history. Co-adaptation and its examples are often seen as evidence for co-evolution.
Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 1.05%. These environments differ from marine conditions in many ways, the most obvious being the difference in levels of salinity. To survive fresh water, the fish need a range of physiological adaptations.
Lepidophagy is a specialised feeding behaviour in fish that involves eating of scales of other fish. Lepidophagy is widespread, having been independently evolved in at least five freshwater families and seven marine families. A related feeding behavior is pterygophagy, which are fish that feed on the fins of other fish.
Pharyngeal jaws are a "second set" of jaws contained within an animal's throat, or pharynx, distinct from the primary or oral jaws. They are believed to have originated as modified gill arches, in much the same way as oral jaws. Originally hypothesized to have evolved only once, current morphological and genetic analyses suggest at least two separate points of origin. Based on connections between musculoskeletal morphology and dentition, diet has been proposed as a main driver of the evolution of the pharyngeal jaw. A study conducted on cichlids showed that the pharyngeal jaws can undergo morphological changes in less than two years in response to their diet. Fish that ate hard shelled prey had a robust jaw with molar-like teeth fit for crushing their durable prey. Fish that ate softer prey, on the other hand, exhibited a more slender jaw with thin, curved teeth used for tearing apart fleshy prey. These rapid changes are an example of phenotypic plasticity, wherein environmental factors affect genetic expression responsible for pharyngeal jaw development. Studies of the genetic pathways suggest that receptors in the jaw bone respond to the mechanical strain of biting hard-shelled prey, which prompts the formation of a more robust set of pharyngeal jaws.
Evolutionary aesthetics refers to evolutionary psychology theories in which the basic aesthetic preferences of Homo sapiens are argued to have evolved in order to enhance survival and reproductive success.
Most bony fishes have two sets of jaws made mainly of bone. The primary oral jaws open and close the mouth, and a second set of pharyngeal jaws are positioned at the back of the throat. The oral jaws are used to capture and manipulate prey by biting and crushing. The pharyngeal jaws, so-called because they are positioned within the pharynx, are used to further process the food and move it from the mouth to the stomach.
Symphysodon tarzoo, the green discus, is a species of cichlid native to rivers of the western Amazon Basin upriver from the Purus arch, although it occasionally occurs downstream. An introduced population in the Nanay River is based on stock from the Tefé region. The green discus is found in blackwater habitats with a high temperature of 27–30 °C (81–86 °F) and low pH of 4.8–5.9. Although also known from whitewater, its preference for lentic habitats such as floodplains means that the water contain little suspended material.
Kirk O. Winemiller is an American ecologist, known for research on community ecology, life history theory, food webs, aquatic ecosystems, tropical ecology and fish biology. A strong interest has been convergent evolution and patterns, causes and consequences of biological diversity, particularly with respect to fishes. His research also has addressed the influence of hydrology on the ecological dynamics of fluvial ecosystems and applications of this knowledge for managing aquatic biodiversity and freshwater resources in the United States and other regions of the world. He currently is a University Distinguished Professor and Regents Professor at Texas A&M University and an Elected Fellow of the Ecological Society of America, American Fisheries Society and the American Association for the Advancement of Science.
Jeannine Cavender-Bares is a professor at the University of Minnesota in the Department of Ecology, Evolution & Behavior. Her research integrates evolutionary biology, ecology, and physiology by studying the functional traits of plants, with a particular focus on oaks.
1 2 3 Bock, W. J. 1994. Concepts and methods in ecomorphology. Journal of Biosciences 19:403–413.
↑ Beer, G. 1954. Archaeopteryx and evolution. The Advancement of Science 11: 160–170.
↑ Karr, J.R. and James, F.C. 1975. Eco-morphological configurations and convergent evolution of species and communities; in Ecology and Evolution of Communities (eds). M.L. Cody and J.M. Diamond. Cambridge, Massachusetts: Harvard University Press. 258–291
↑ Leisler, B. 1977. Morphological Aspects of Ecological Specializations in Bird Genera. American Zoologist 19(3): 1014–1014.
↑ Bock, W. Van Walhert, J. 1965. The role of adaptive mechanisms in the origin of higher levels of organisation. Systematic Biology 14(4): 272–287. [dead link]
↑ Bock, W., G. Lanzavecchia, and R. Valvassori. 1991. Levels of complexity and organismal organization. Selected Symposia and Monographs UZI. Vol 5 181–212.
↑ Wainwright, P. C. (1996). "Ecological Explanation through Functional Morphology: The Feeding Biology of Sunfishes". Ecology. 77 (5): 1336–1343. doi:10.2307/2265531. JSTOR2265531.
↑ Moermond, T., and J. Denslow. 1983. Fruit choice in neotropical birds: effects of fruit type and accessibility on selectivity. The Journal of Animal Ecology 52(2): 407–420.
↑ Sibbing, F., L. Nagelkerke, and J. Osse. 1994. Ecomorphology as a tool in fisheries-Identification and ecotyping of Lake Tana Barbs (Barbus-Intermedius COmplex), Ethiopia. Netherlands Journal of Agricultural Science 42:77–85. Royal Netherlands Soc Agr Sci.
↑ Griffen, B. D., and H. Mosblack. 2011. Predicting diet and consumption rate differences between and within species using gut ecomorphology. The Journal of animal ecology 80:854–63.
↑ Goodman, B. A., and P. T. J. Johnson. 2011. Ecomorphology and disease: cryptic effects of parasitism on host habitat use, thermoregulation, and predator avoidance. Ecology 92:542–548.
1 2 3 Norton, S. F., J. J. Luczkovich, and P. J. Motta. 1995. The role of ecomorphological studies in the comparative biology of fishes. Environmental Biology of Fishes 44:287–304.
↑ Fryer, G. T. and Iles, T. D. The cichlid fishes of the great lakes of Africa: their biology and evolution. 1972. Oliver and Boyd, Cornell University.
1 2 Scott, R. S., and W. A. Barr. 2014. Ecomorphology and phylogenetic risk: Implications for habitat reconstruction using fossil bovids. Journal of human evolution 73:47–57
↑ Plummer, T. W., Bishop, L. C., Hertel, F. 2008. Habitat preference of extant African bovids based on astragalus morphology: operationalizing ecomorphology for palaeoenvironmental reconstruction. Journal of Archaeological Science 35(11): 3016–3027
↑ Chan, M. D. 2001. Fish ecomorphology: predicting habitat preferences of stream fishes from their body shape. Virginia Polytechnic Institute and State University.
Betz, O. (2006), Ecomorphology: Integration of form, function, and ecology in the analysis of morphological structures, Mitteilungen der Deutschen Gesellschaft für Allgemeine und Angewandte Entomologie 15, 409-416.
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