Eco-evolutionary dynamics refers to the reciprocal effects that ecology and evolution have on each other. [1] The effects of ecology on evolutionary processes are commonly observed in studies, but the realization that evolutionary changes can be rapid led to the emergence of eco-evolutionary dynamics. [2] The idea that evolutionary processes can occur quickly and on one timescale with ecological processes led scientists to begin studying the influence evolution has on ecology along with the affects ecology has on evolution. [3] Recent studies have documented eco-evolutionary dynamics and feedback, which is the cyclic interaction between evolution and ecology, [4] in natural and laboratory systems at different levels of biological organization, such as populations, communities, and ecosystems. [2]
Since Charles Darwin published On the Origin of Species in 1859, [5] evolution was known to occur across a long, geographical timescale. [1] It was thought evolutionary processes occurred separately from ecological timescales because they were too slow to interact with ecological changes. [3] Once it was recognized that evolutionary processes could happen relatively quickly and on a shorter timescale, which was contrary to the previous idea associated with Darwin's work, the concept of eco-evolutionary dynamics emerged. [1]
While it was recognized by Darwin and R.A. Fisher (1930) that evolutionary and ecological processes were intertwined, it wasn’t until the 1950s and 1960s that scientists would begin to hypothesize the influence evolution has on ecology. [1] The possibility of ecological processes being influenced by evolution and not occurring independently from the evolutionary timescale led scientists to explore the reciprocal interactions between ecology and evolution in natural and laboratory systems. [1] Indeed, increasing evidence shows that evolution can also operate on fine time scales simultaneously with ecological processes. [6] [7] While it has been difficult to research eco-evolutionary dynamics in natural systems, it has been successfully documented using models and laboratory studies. [2] Different studies have documented the interplay between evolutionary and ecological processes and their occurrence on one timescale in populations, communities, and ecosystems. [2] [8] [9] [10] [11] [12] Contributions to the research of eco-evolutionary dynamics include empirical studies on rotifers and green algae, [13] Darwin’s finches, [14] fruit flies, [15] alewife–zooplankton interactions, [4] and Trinidadian guppies. [16] [4]
In eco-evolutionary dynamics, there is a cyclic interaction between evolution and ecology referred to as eco-evolutionary feedback. An organism's ecological interactions can lead to evolutionary changes of its traits. In response, the evolutionary changes alter the ecological interactions of the organism, and the cycle repeats. [4] The feedback loop occurs because of the interactions between rapid evolution and ecological changes. The change in the distribution of heritable traits or genotype frequency within a population over a few generations is considered rapid evolution or microevolution. [3] Eco-evolutionary feedback is present at different biological levels of organization, such as populations, communities, and ecosystems. [1] [4]
Rapid evolution plays a significant role in shaping ecological processes within populations and communities, for eco-evolutionary feedback allows for the maintenance and persistence of trait variation in a species because it alters population and community dynamics. [3] [17] When population dynamics are affected by the variation in heritable traits, within a few generations it can change the strength and direction of natural selection acting on the traits. [3] [13] Population dynamics are also affected by the landscape of the environment a species lives in. The landscape can influence the distribution of genetic variation within a population because it alters gene frequencies. The change in gene frequencies results in a change in phenotypic traits, which determine an organism’s reproduction and survival, and the evolutionary changes affect population dynamics. [1] Eco-evolutionary dynamics are also evident at the community level. [3] Short-term evolution can affect the speed at which organisms adapt to fluctuating environments, and the rate of evolution can reshape the community structure. [3] [17] An example of eco-evolutionary dynamics in populations and communities is when two species interact. In a predator-prey system, eco-evolutionary feedback results in the oscillation of population densities as the selection of traits fluctuate. [3] [8] The evolutionary change in one species can drive change to heritable traits and demography in the other species, which in turn can affect the first species. [8] Rotifer-algal chemostats has been used to observe rapid evolution altering predator-prey interactions. Yoshida et al. [13] compared rotifer cultures combined with multiple algal clones to rotifer cultures combined with a single clone. Variation in the defenses against consumption in the algal genotypes influence the growth rate and population density of the rotifers, which feedback to alter the gene frequencies in the algae. In the single clone algae, prey evolution was inhibited because of the lack of variation. The lack of adaptive evolution in the single clone prevented eco-evolutionary feedback in the predator-prey system. [4]
While eco-evolutionary dynamics have been successfully documented using models and laboratory studies, It has been difficult to research eco-evolutionary dynamics in natural systems. [13] It is especially more challenging to study evolutionary and ecological dynamics in an ecosystem because of the large number of species and complex interactions that comprise an ecosystem. [8] The realization that rapid evolution can alter ecological processes has led researchers to take an eco-evolutionary approach while observing the consequences of rapid evolutionary change in ecosystems in contemporary time. [8] The idea of evolution being studied on entire ecosystems dates back to the 1920s. [18] It was hypothesized that evolution through natural selection would operate to achieve maximum energy flux through an ecosystem. Since then, progression toward merging ecosystem ecology and evolution continued, and studies have revealed the impact evolution has on ecosystem ecology and vice versa. In an ecosystem, the interactions between individuals and their environment can drive changes in evolution. Due to the complexity of ecosystems, organisms experience multiple interactions in their environment, and these interactions can indirectly change the selective pressures placed on them. [8] The selective pressures lead to genetic and phenotypic variation, which influence ecosystem variables such as decomposition, nutrient cycling, and primary productivity. [4] An example of ecosystem variables being influenced by evolution is a mesocosm experiment using Trinidadian guppies. Predation pressure in an environment caused evolutionary changes in the life-history traits of the guppies, which affected ecosystem processes. [4] Guppies' living in an environment with high predation lead to the fish giving birth more frequently and to smaller offspring. These offspring also matured at an earlier age and at a smaller size than guppies living in a low predation environment. Populations with more and smaller guppies increased the amount of nitrogen and phosphorus in the nutrient pool of an ecosystem, which increased algal biomass. The increase in algal biomass feedback to influence the evolution of other guppy traits. So evolutionary changes in the life-history traits of Trinidadian guppies caused by predation resulted in ecological effects at the community and ecosystem level, which feedback to influence the evolution of other traits in the guppies. [4] Another hypothesis of eco-evolutionary dynamics in ecosystems involves the evolution of food webs. Scientists began to study the evolution of food webs in ecosystems through the use of evolutionary simulation models to get an understanding of the structure and function of current ecosystems. The results of their models lead to the generation of food webs that are similar to our existing food webs. [8]
Ecology is the natural science of the relationships among living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere levels. Ecology overlaps with the closely related sciences of biogeography, evolutionary biology, genetics, ethology, and natural history.
Theoretical ecology is the scientific discipline devoted to the study of ecological systems using theoretical methods such as simple conceptual models, mathematical models, computational simulations, and advanced data analysis. Effective models improve understanding of the natural world by revealing how the dynamics of species populations are often based on fundamental biological conditions and processes. Further, the field aims to unify a diverse range of empirical observations by assuming that common, mechanistic processes generate observable phenomena across species and ecological environments. Based on biologically realistic assumptions, theoretical ecologists are able to uncover novel, non-intuitive insights about natural processes. Theoretical results are often verified by empirical and observational studies, revealing the power of theoretical methods in both predicting and understanding the noisy, diverse biological world.
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthparts adapted to rasping or grinding. Horses and other herbivores have wide flat teeth that are adapted to grinding grass, tree bark, and other tough plant material.
In ecology, the competitive exclusion principle, sometimes referred to as Gause's law, is a proposition that two species which compete for the same limited resource cannot coexist at constant population values. When one species has even the slightest advantage over another, the one with the advantage will dominate in the long term. This leads either to the extinction of the weaker competitor or to an evolutionary or behavioral shift toward a different ecological niche. The principle has been paraphrased in the maxim "complete competitors cannot coexist".
Paleoecology is the study of interactions between organisms and/or interactions between organisms and their environments across geologic timescales. As a discipline, paleoecology interacts with, depends on and informs a variety of fields including paleontology, ecology, climatology and biology.
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 inquiry 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.
Niche construction is the process by which an organism alters its own local environment. These alterations can be a physical change to the organism’s environment or encompass when an organism actively moves from one habitat to another to experience a different environment. Examples of niche construction include the building of nests and burrows by animals, and the creation of shade, influencing of wind speed, and alternation of nutrient cycling by plants. Although these alterations are often beneficial to the constructor, they are not always.
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.
Niche microdifferentiation is the process a species undergoes to reach genetic diversity within that species; it is the process by which an ecotype is created. This process is regulated by various environmental influences whether they be morphological, spatial, and/or temporal. This means that a trait of one organism in one area is not advantageous for the same species in a different location: "the trait that alters the environment in a manner that is favorable to growth tends to be reinforced and this positive feedback can further, to a certain extent, modify the selection pressure on itself". For example, a species of moth which is white and lives in an area where tree bark is stripped and tree color is white will more easily survive than a white moth in a different location where trees are moss-covered and green. This leads to adaptations that allow the species to exist in a slightly different environment. Organisms within the same species can undergo phenotypic and genotypic changes due to niche microdifferentiation. Conspecific organisms can vary in color, size, diet, behavior, and morphology due to differences in environmental pressures. Related topics include epigenetics, niche differentiation, and evolutionary biology.
Functional ecology is a branch of ecology that focuses on the roles, or functions, that species play in the community or ecosystem in which they occur. In this approach, physiological, anatomical, and life history characteristics of the species are emphasized. The term "function" is used to emphasize certain physiological processes rather than discrete properties, describe an organism's role in a trophic system, or illustrate the effects of natural selective processes on an organism. This sub-discipline of ecology represents the crossroads between ecological patterns and the processes and mechanisms that underlie them.
The following outline is provided as an overview of and topical guide to ecology:
In ecology, a community is a group or association of populations of two or more different species occupying the same geographical area at the same time, also known as a biocoenosis, biotic community, biological community, ecological community, or life assemblage. The term community has a variety of uses. In its simplest form it refers to groups of organisms in a specific place or time, for example, "the fish community of Lake Ontario before industrialization".
Island ecology is the study of island organisms and their interactions with each other and the environment. Islands account for nearly 1/6 of earth’s total land area, yet the ecology of island ecosystems is vastly different from that of mainland communities. Their isolation and high availability of empty niches lead to increased speciation. As a result, island ecosystems comprise 30% of the world’s biodiversity hotspots, 50% of marine tropical diversity, and some of the most unusual and rare species. Many species still remain unknown.
Ecological fitting is "the process whereby organisms colonize and persist in novel environments, use novel resources or form novel associations with other species as a result of the suites of traits that they carry at the time they encounter the novel condition". It can be understood as a situation in which a species' interactions with its biotic and abiotic environment seem to indicate a history of coevolution, when in actuality the relevant traits evolved in response to a different set of biotic and abiotic conditions.
Evolving digital ecological networks are webs of interacting, self-replicating, and evolving computer programs that experience the same major ecological interactions as biological organisms. Despite being computational, these programs evolve quickly in an open-ended way, and starting from only one or two ancestral organisms, the formation of ecological networks can be observed in real-time by tracking interactions between the constantly evolving organism phenotypes. These phenotypes may be defined by combinations of logical computations that digital organisms perform and by expressed behaviors that have evolved. The types and outcomes of interactions between phenotypes are determined by task overlap for logic-defined phenotypes and by responses to encounters in the case of behavioral phenotypes. Biologists use these evolving networks to study active and fundamental topics within evolutionary ecology.
Community genetics is a recently emerged field in biology that fuses elements of community ecology, evolutionary biology, and molecular and quantitative genetics. Antonovics first articulated the vision for such a field, and Whitham et al. formalized its definition as "The study of the genetic interactions that occur between species and their abiotic environment in complex communities." The field aims to bridge the gaps in the study of evolution and ecology, within the multivariate community context in which ecological and evolutionary features are embedded. The documentary movie A Thousand Invisible Cords provides an introduction to the field and its implications.
Matjaž Perc is Professor of Physics at the University of Maribor in Slovenia, and director of the Complex Systems Center Maribor. He is member of Academia Europaea and among top 1% most cited physicists according to Thomson Reuters Highly Cited Researchers. He is Outstanding Referee of the Physical Review and Physical Review Letters journals, and Distinguished Referee of EPL. He received the Young Scientist Award for Socio-and Econophysics in 2015. His research has been widely reported in the media and professional literature.
Ruth Geyer Shaw is a professor and principal investigator in the Department of Ecology, Evolution and Behavior at the University of Minnesota. She studies the processes involved in genetic variation, specializing in plant population biology and evolutionary quantitative genetics. Her work is particularly relevant in studying the effects of stressors such as climate instability and population fragmentation on evolutionary change in populations. She has developed and applied new statistical methods for her field and is considered a leading population geneticist.
Jessica Hua is an associate professor in the Department of Biological Sciences at Binghamton University, NY. In addition Hua is the Director for the Center for Integrated Watershed Studies at Binghamton University which focuses on understanding watersheds and the human influences on them through research. She is a herpetologist and oversees her own lab, The Hua Lab, where they focus on ecological interactions, evolutionary processes and ecological-evolutionary feedbacks. Hua's background has led to her appreciation of education with coming from a refugee family who "epitomizes the concept of the American Dream". Her research aims to help others gain opportunities while also establishing a lab that is inclusive and diverse. Hua also enjoys a variety of sports and plays disc golf professionally since 2016.
David M. Post is a research scientist and academic administrator. He is currently a professor of Ecology and Evolutionary Biology at Yale University and the Vice President ., Dean of Faculty, and Visiting Wong Ngit Liong Professor at Yale-NUS College, the first liberal arts college in Singapore. Post is an aquatic ecologist who studies food webs, evolution, and stable isotopes in lakes and rivers in Connecticut and Kenya.