Academic literature on the topic 'Speciation and extinction'
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Journal articles on the topic "Speciation and extinction"
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Bull, J. W., and M. Maron. "How humans drive speciation as well as extinction." Proceedings of the Royal Society B: Biological Sciences 283, no. 1833 (June 29, 2016): 20160600. http://dx.doi.org/10.1098/rspb.2016.0600.
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A central topic for conservation science is evaluating how human activities influence global species diversity. Humanity exacerbates extinction rates. But by what mechanisms does humanity drive the emergence of new species? We review human-mediated speciation, compare speciation and known extinctions, and discuss the challenges of using net species diversity as a conservation objective. Humans drive rapid evolution through relocation, domestication, hunting and novel ecosystem creation—and emerging technologies could eventually provide additional mechanisms. The number of species relocated, domesticated and hunted during the Holocene is of comparable magnitude to the number of observed extinctions. While instances of human-mediated speciation are known, the overall effect these mechanisms have upon speciation rates has not yet been quantified. We also explore the importance of anthropogenic influence upon divergence in microorganisms. Even if human activities resulted in no net loss of species diversity by balancing speciation and extinction rates, this would probably be deemed unacceptable. We discuss why, based upon ‘no net loss’ conservation literature—considering phylogenetic diversity and other metrics, risk aversion, taboo trade-offs and spatial heterogeneity. We conclude that evaluating speciation alongside extinction could result in more nuanced understanding of biosphere trends, clarifying what it is we actually value about biodiversity.
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Valentine, James W., and Timothy D. Walker. "Extinctions in a model taxonomic hierarchy." Paleobiology 13, no. 2 (1987): 193–207. http://dx.doi.org/10.1017/s0094837300008745.
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A computer model of background and mass extinctions in a taxonomic hierarchy has been used to study the effects of different extinction patterns in a search for clues as to the causes of actual extinction events. Model taxa at four levels were built up from speciation events in adaptive space according to rules of origination which seem plausible biologically. The frequency distribution of species among the three higher taxonomic levels in the model is similar to that in living marine taxa which have good fossil records. Three mass extinction patterns were imposed on the model after species diversity had attained equilibrium (i.e., when speciation = background extinction): random; bloc (contiguous niches were cleared); and clade (all members of selected higher taxa were removed). Effects on the taxonomic profile varied with pattern. Four of the five historical mass extinctions resemble the effects of the random pattern. End-Permian families were harder hit than those in the random model, but this may be a result of an extremely high species extinction level. It is concluded that the effect of extinctions on the taxonomic hierarchy provides a tool to help in understanding extinction causes.
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Hulbert, Richard C. "Taxonomic evolution in North American Neogene horses (subfamily Equinae): the rise and fall of an adaptive radiation." Paleobiology 19, no. 2 (1993): 216–34. http://dx.doi.org/10.1017/s0094837300015888.
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The 18 m.y. history of the subfamily Equinae (exclusive of Archaeohippus and “Parahippus”) in North America consisted of a 3-m.y. radiation phase, a 9-m.y. steady-state diversity phase, and a 6-m.y. reduction phase. During the steady-state phase, species richness varied between 14 and 20, with two maxima at about 13.5 and 6.5 Ma. Species richness of the tribes Hipparionini and Equini was about equal through the middle Miocene, but hipparionines consistently had more species in the late Miocene and early Pliocene. Overall mean species duration was 3.2 m.y. (n = 50), or an average extinction rate of 0.31 m.y.-1 During the radiation phase, speciation rates were very high (0.5 to 1.4 m.y.-1), while extinction rates were low (<0.10 m.y.-1). Speciation and extinction rates both averaged about 0.15 m.y.-1 during the steady-state phase, with extinction rates having more variation. Extinction rates increased fourfold during the reduction phase, while speciation rates declined slightly. Late Hemphillian extinctions affected both tribes severely, not just the three-toed hipparionines, and were correlated with global climatic change.
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Magañón-Puebla, Susana. "Diferentes tasas evolutivas entre grupos de angiospermas. Eudicotiledóneas." Botanical Sciences, no. 58 (April 27, 2017): 137. http://dx.doi.org/10.17129/botsci.1494.
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Applying analytical models to two clades, eudicotyledons and paleoherbs, three filogeny models were explored and analyzed with parameters that vary from low extinction rates to high speciation rates. Filogeny Model I suggest that the probability ty of obtaining a difference in species distribution, between the two sister clades, as the observed, or higher, varies between 15.2% with high speciation rates and 16.7% with low extinction rates. In Filogeny Model II the probability of obtaining a species distribution similar to the observed one or higher, varies between 15.7% with high speciation rates to 17.4% with low extinction rates. In contrast, probability of obtaining a species distribution like the observed or higher in Filogeny Model III varies from 2.5% with high speciation rates to 2.8% with low extinction rates. Accordingly with the tree Models, the probability of obtaining a numerical difference at the species level between eudicotyledons and its sister group are low. However, results suggest the eudicotyledons are characterize by higher evolutionary rates (speciation-extinction) compared with other groups of angiosperms.
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Chen, Youhua. "An island biogeography model for beta diversity and endemism: The roles of speciation, extinction and dispersal." International Journal of Biomathematics 08, no. 01 (January 2015): 1550011. http://dx.doi.org/10.1142/s1793524515500114.
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A community composition island biogeography model was developed to explain and predict two community patterns (beta diversity and endemism) with the consideration of speciation, extinction and dispersal processes. Results showed that rate of speciation is positively and linearly associated with beta diversity and endemism, that is, increasing species rates typically could increase the percentage of both endemism and beta diversity. The influences of immigration and extinction rates on beta diversity and endemism are nonlinear, but with numerical simulation, I could observe that increasing extinction rates would lead to decreasing percentage of endemism and beta diversity. The role of immigration rate is very similar to that of speciation rate, having a positive relationship with beta diversity and endemism. Finally, I found that beta diversity is closely related to the percentage of endemism. The slope of this positive relationship is determined jointly by different combinations of speciation, extinction and immigration rates.
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Archibald, J. David. "The importance of phylogenetic analysis for the assessment of species turnover: a case history of Paleocene mammals in North America." Paleobiology 19, no. 1 (1993): 1–27. http://dx.doi.org/10.1017/s0094837300012288.
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During the latest Cretaceous and the Paleocene in western North America, disappearance rates for mammalian genera track appearance rates, both reaching their peak in the early Paleocene (Puercan) following the extinction of non-avian dinosaurs. Some of the disappearances during this time were pseudoextinctions that resulted when ancestral species disappeared during speciation.Species-level cladistic analyses and a well-constrained biostratigraphic framework are required to study this form of pseudoextinction. Cladistic analyses show that monophyly cannot be established or rejected for some species because these species lack autapomorphies (uniquely derived character states) that unite their constituent members. Such taxa, termed metaspecies, are potential ancestors to species and higher clades with which they share a node in the cladogram.A hypothetical species-level cladistic analysis coupled with three different hypothetical biostratigraphies shows how different models of speciation (bifurcation, budding, or anagenesis) result in very different patterns of true versus pseudoextinction. Depending on the speciation model, true extinction can be overestimated by as much as a factor of four, raising the specter of mass extinction. Species-level studies for three early Tertiary mammalian taxa—taeniodont eutherians, taeniolabidid multituberculates, and periptychid ungulates—use the same procedures. They show that almost 25% of disappearances during the early Paleocene (Puercan) for species in the analysis were pseudoextinctions of metaspecies. Budding and anagenetic-like peripatric speciation, but not bifurcation, are seen in the three examples.Equating disappearance to true extinction can profoundly affect interpretations of faunal turnover, especially during mass extinctions or major faunal reorganizations. Some authors use pseudoextinction to describe the taxonomic rather than evolutionary disappearance of nonmonophyletic groups. Pseudoextinction, as used here refers only to the evolutionary disappearance of metaspecies via speciation. Both usages seem appropriate but should not be confounded.
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John Sepkoski, J. "Rates of speciation in the fossil record." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 353, no. 1366 (February 28, 1998): 315–26. http://dx.doi.org/10.1098/rstb.1998.0212.
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Data from palaeontology and biodiversity suggest that the global biota should produce an average of three new species per year. However, the fossil record shows large variation around this mean. Rates of origination have declined through the Phanerozoic. This appears to have been largely a function of sorting among higher taxa (especially classes), which exhibit characteristic rates of speciation (and extinction) that differ among them by nearly an order of magnitude. Secular decline of origination rates is hardly constant, however; many positive deviations reflect accelerated speciation during rebounds from mass extinctions. There has also been general decline in rates of speciation within major taxa through their histories, although rates have tended to remain higher among members in tropical regions. Finally, pulses of speciation appear sometimes to be associated with climate change, although moderate oscillations of climate do not necessarily promote speciation despite forcing changes in species' geographical ranges.
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Bennett, Dominic J., Mark D. Sutton, and Samuel T. Turvey. "Evolutionarily distinct “living fossils” require both lower speciation and lower extinction rates." Paleobiology 43, no. 1 (November 24, 2016): 34–48. http://dx.doi.org/10.1017/pab.2016.36.
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AbstractAs a label for a distinct category of life, “living fossil” is controversial. The term has multiple definitions, and it is unclear whether the label can be genuinely used to delimit biodiversity. Even taking a purely phylogenetic perspective in which a proxy for the living fossil is evolutionary distinctness (ED), an inconsistency arises: Does it refer to “dead-end” lineages doomed to extinction or “panchronic” lineages that survive through multiple epochs? Recent tree-growth model studies indicate that speciation rates must have been unequally distributed among species in the past to produce the shape of the tree of life. Although an uneven distribution of speciation rates may create the possibility for a distinct group of living fossil lineages, such a grouping could only be considered genuine if extinction rates also show a consistent pattern, be it indicative of dead-end or panchronic lineages. To determine whether extinction rates also show an unequal distribution, we developed a tree-growth model in which the probability of speciation and extinction is a function of a tip’s ED. We simulated thousands of trees in which the ED function for a tip is randomly and independently determined for speciation and extinction rates. We find that simulations in which the most evolutionarily distinct tips have lower rates of speciation and extinction produce phylogenetic trees closest in shape to empirical trees. This implies that a distinct set of lineages with reduced rates of diversification, indicative of a panchronic definition, is required to create the shape of the tree of life.
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Stanley, Steven M. "Population size, extinction, and speciation: the fission effect in Neogene Bivalvia." Paleobiology 12, no. 1 (1986): 89–110. http://dx.doi.org/10.1017/s0094837300003006.
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The extinction of a species represents reduction of both geographic range and population size to zero. Most workers have focused on geographic range as a variable strongly affecting the vulnerability of established species to extinction, but Lyellian percentages for Neogene bivalve faunas of California and Japan suggest that population size is a more important variable along continental shelves. The data employed to reach this conclusion are Lyellian percentages for latest Pliocene (∼2 ma old) bivalve faunas of California and Japan (N = 245 species). These regions did not suffer heavy extinction during the recent Ice Age, and for each region the Lyellian percentage is 70%–71%.Discrepancies in population size appear to explain the following differences in survivorship to the Recent (Lyellian percentage) for three pairs of subgroups: (1) burrowing nonsiphonate species (42%) versus burrowing siphonate species (84%), which suffer less heavy predation; (2) burrowing nonsiphonate species of small size (73%) versus burrowing nonsiphonate species of large body size (96%); (3) Pectinacea (30%) versus other epifauna (71%), which suffer less heavy predation. During the Mesozoic Era, when predation was less effective in benthic settings, mean species duration for the Pectinacea was much greater (∼20 ma).Along the west coast of North and Central America, mean geographic range is greater for siphonate species of large body size than for siphonate species of small body size and greater still for pectinacean species. These ranges are inversely related to mean species longevity for the three groups, which indicates that geographic range is not of first-order importance in influencing species longevity. Species with nonplanktotrophic development neither exhibit narrow geographic ranges along the west coast of North and Central America nor have experienced high rates of extinction in California and Japan.Rates of extinction are so high for Neogene pectinaceans and nonsiphonate burrowers that without enjoying high rates of speciation these groups could not exist at the diversities they have maintained during the Neogene Period. They are apparently speciating rapidly because of the fission effect: the relatively frequent generation of new species from populations that are fragmented by heavy predation. Thus, ironically, there may be a tendency for high rates of speciation to be approximately offset by high rates of extinction. Only if mean population size for species in a particular group becomes extremely small is it likely to result in a high rate of extinction and a low rate of speciation—and hence a dramatic decline of the group. The fission effect may contribute to the general correlation in the animal world between rate of speciation and rate of extinction.
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Stanley, Steven M., Karen L. Wetmore, and James P. Kennett. "Macroevolutionary differences between the two major clades of Neogene planktonic foraminifera." Paleobiology 14, no. 3 (1988): 235–49. http://dx.doi.org/10.1017/s0094837300011970.
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Being of especially high quality, the Neogene fossil record of planktonic foraminifera offers special opportunities for assessing patterns of extinction and speciation. A variety of metrics indicates that within this group the mean duration of lineages has been much shorter (rate of extinction has been higher) for the globorotaliid clade than for the globigerinid clade. Furthermore, in the globorotaliid clade rates of extinction and speciation have not been closely linked to changes in diversity, but rather have been relatively high even at times when diversity has undergone little change. Thus, the globorotaliid clade has undergone more rapid evolutionary turnover than the globigerinid clade. Data for living species reveal that neither geographic range nor temperature tolerance is the primary factor controlling lineage duration. On the other hand, there is evidence that lineages marked by low abundance (small population size) are relatively short-lived. The reason that globorotaliid lineages have generally survived for shorter intervals, on the average, may be that their populations have been less abundant and less stable. Usually they live deeper in the water column, where food is often sparse, and many flourish only in areas of upwelling. Furthermore, the globorotaliids lack symbiotic algae for nutritional support. The same ecological factors may have accelerated speciation in the globorotaliid clade, by causing species to be patchily distributed. Thus, population size and structure have been more important than geographic range in determining rates of extinction and speciation. This parallels the situation for Neogene marine bivalves.For planktonic foraminifera, as for Western Atlantic Bivalvia, the normal pattern of extinction was reversed in late Pliocene time, apparently in response to climatic cooling. The globigerinids suffered a sudden pulse of extinction. The deeper dwelling globorotaliids fared better; probably many of their species benefited from elevation of the seasonal thermocline into the photic zone. At the same time, rate of speciation declined in the globorotaliid clade, which supports the idea, inferred from the evolutionary history of marine bivalves, that an increase in the size and stability of populations should depress both rate of extinction and rate of speciation.
Dissertations / Theses on the topic "Speciation and extinction"
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Stadler, Tanja. "Evolving trees: models for speciation and extinction in phylogenetics." kostenfrei, 2008. http://mediatum2.ub.tum.de/doc/672309/672309.pdf.
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Kirchman, Jeremy J. "Speciation and extinction of flightless rails (Aves: Gallirallus) in Oceania." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0015121.
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Waldron, Anthony Simon. "Geographic range size : speciation, extinction and what happens in-between." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31706.
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I studied the impact of geographic range size on clade diversification rates. Recent studies have suggested that, although geographic range size shows phylogenetic signal, this signal may be a statistical artefact. I created two models of range size evolution to determine the expected division of range size at speciation and to model the subsequent evolution of range size in sister species. Range size "symmetry" (the degree of similarity between sister species' range sizes) was then compared to these expectations. The range size of sister species of birds both show phylogenetic signal and are more similar than expected under the model, suggesting that range size is heritable. I then show that range size has a positive relationship with diversification rate in young clades of primates, but that the relationship may become asymptotic or even negative at very large range sizes. This is the first evidence of a non-linear relationship between range size and diversification rate, and may also be evidence of a non-linear relationship between range size and speciation rate. Finally, I test the novel hypothesis that clades which can tolerate the extinction risks associated with range restriction will diversify more quickly than intolerant clades. I find that risk-tolerant primate clades do have higher diversification rates. I also find, surprisingly, that the biological correlates of extinction risk tolerance are habitat specialisation and small geographic range size. "Rare" species (i.e. those with narrow geographic distributions or small population sizes) may therefore be characterised by their tolerance of extinction risk, rather than being risk-prone as is widely thought.Science, Faculty of
Zoology, Department of
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Smart, Christopher W. "Ecological controls on patterns of speciation and extinction in deep-sea benthic forminifera." Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332824.
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Monroe, Melanie. "The tempo and mode of evolution : a neontological reappraisal." Doctoral thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-49761.
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The theory of “punctuated equilibrium” suggests that species evolve rapidly during or immediately upon speciation, “punctuating” long periods of little or no morphological evolution. Here I confirm that body size differences within clades of birds and mammals are best explained using a model of punctuated evolution. This allows me to suggest that rates of speciation and extinction are responsible for why there are more small mammals than large, as large mammals likely speciate and go extinct at a higher rate than small mammals, and hence undergo cladogenetic change more often. Likewise, mammals appear to evolve at a higher rate than birds, because mammals, as a whole, speciate and go extinct at a higher rate than birds. Furthermore I show that mass extinctions and competition, i.e. forms of natural selection, do not seem to explain differences in body size between species on a macroevolutionary scale. Taken together, these findings not only contradict the idea that apparently different rates of evolution are due to differential selection intensities, and emphasize the importance of the speciation process in evolution, but raise the intriguing question as to what limits evolution in established species. Here I suggest that phenotypic traits, dependent on one another for development and/or function may constrain evolution by exerting stabilizing selection from within the organism, as opposed to external environmental selection, which has been the main focus of evolutionary studies thus far.Teorin om "punkterad jämvikt" säger att arter utvecklas snabbt under och omedelbart efter artbildning, vilket "punkterar" långa perioder med lite eller ingen morfologisk föränding. I den här avhandlingen visar jag att skillnader i kroppsstorlek inom klader (grupp med gemensam förfader) hos fåglar och däggdjur förklaras bäst när man använder en modell med punkterad evolution. Detta gör i sin tur att jag kan föreslå att hastigheten var med artbildning och utdöende sker, förklarar varför det finns fler små däggdjur än stora, eftersom stora däggdjur sannolikt bildar nya arter och dör ut med en högre hastighet än små däggdjur. Likaså förefaller däggdjur i sin helhet att evolvera med en högre hastighet än fåglar, detta eftersom däggdjur bildar nya arter och dör ut med en högre hastighet än fåglar. Dessutom visar jag att massutdöenden och konkurrens (naturlig selektion) inte verkar förklara skillnader mellan arter över makroevolutionära skalor (över geologisk tid). Sammantaget motsäger dessa resultat inte bara idén om att skenbart olika hastighet på evolution främst beror på skillnader i selektionstryck utan understryker också vikten av artbildningsprocessen som en viktig faktor som styr evolutionens hastighet. Dessutom leder dessa resultat till frågan om vad som begränsar evolutionen hos redan etablerade arter. Här föreslår jag att fenotypiska karaktärsdrag som är beroende av varandra för sin funktion och utveckling kan begränsa evolutionen genom att utöva stabiliserande selektion inifrån organismen, i motsats till selektion från den omgivande miljön vilket har varit fokus för de flesta evolutionära studier hittills.
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Peart, Daniel Chad. "CONTINUOUS OR PULSE? SIMULATING SPECIATION AND EXTINCTION FROM EAST AND SOUTH AFRICAN FAUNA AT PLIO-PLEISTOCENE FOSSIL SITES." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1429298292.
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Ferreira, Gustavo Burin. "The roles of diet, speciation and extinction on the diversification of birds, and on the assembly of frugivory networks." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/41/41134/tde-22012018-105557/.
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To understand how diversity varies through time and/or space we need to understand speciation and extinction dynamics, and ultimately which factors (biotic or abiotic) affect such dynamics. It has been argued that biological interactions play an important role on the diversification of organisms, but macroevolutionary studies have usually adopted a simple characterization of species interactions. On the other hand ecological studies usually focus on well-characterized interactions of very few species. A network approach can augment our understanding of the ecological roles played by different species but it still lacks an evolutionary perspective preventing us to fully understand how ecological interactions are assembled. Using the available phylogeny, dietary data for virtually all bird species (approximately 9965 species) and a large collection of frugivory net- works, we tested the effect of diet on the diversification of birds, and the relationship between ecological roles within interaction networks and diversification dynamics of frugivorous species. Lastly, using computational simulations, we assessed the per- formance of two state-of-the-art methods to estimate diversification rates using molecular phylogenies. We suggest that omnivory acts as macroevolutionary sink where its ephemeral nature is retrieved through transitions from other guilds rather than from omnivore speciation. We propose that these dynamics result from competition within and among dietary guilds, influenced by the deep-time availability and predictability of food resources. We also observed that in the temperate zone, lineages with high-paced evolutionary dynamics (e.g. higher turn- over rates) typically do not occupy central roles in frugivory net- works, and that these restrictions are modulated by water avail- ability/predictability. Lastly, we found that the two state-of-the art phylogenetic methods perform equally well in diversity de- cline scenarios when estimating current rates, but both fail to detect the true diversification trajectory when extinction rates vary in time. This dissertation contributes to the understanding of biotic and abiotic mechanisms driving both the diversification and the assembly of interaction networks, and also provides important information on the reliability of diversification rate estimates by current, widely used methodsPara entendermos como a biodiversidade varia no tempo e/ou no espaço precisamos entender a dinâmcia de especiação e extinção, e quais fatores (bióticos ou abióticos) afetam essa dinâmica. Acredita-se que as interações biológicas desempen- ham um papel importante na diversificação de organismos, porém estudos macroevolutivos usualmente adotam caracter- izações simples de interações entre espécies. Por outro lado, estudos ecológicos comumente focam na descrição detalhada de interações entre poucas espécies. Uma abordagem de re- des pode aumentar a compreensão dos papéis ecológicos de- sempenhados por diferentes espécies, mas a pouca ênfase em abordagens evolutivas em estudos de redes biológicas nos im- pedem de compreender completamente como essas redes são montadas. Usando a filogenia e dados de dieta disponíveis para virtualmente todas as espécies de aves (aprox. 9965 espécies), e uma grande coleção de redes de frugivoria, investigamos o efeito da dieta na diversificação de aves, e testamos a relação en- tre papéis ecológicos em redes de interação e a dinâmica da di- versificação de espécies frugívoras. Ainda, usando simulações computacionais, avaliamos a performance de dois métodos am- plamente utilizados para estimar taxas de diversificação usando filogenias moleculares. Sugerimos que onivoria atua como um ralo macroevolutivo, onde sua natureza efêmera é recuperada através de transições de outras guildas de dieta ao invés de através da especiação de espécies onívoras. Nós sugerimos que essa dinâmica resulta da competição intra- e entre guildas, in- fluenciada pela disponibilidade e previsibilidade de recursos em ampla escalas de tempo. Nós também observamos que em regiões temperadas, linhagens com uma dinâmica evolutiova mais rápida (maiores taxas de substituição de espécies) em geral não ocupam papéis centrais em redes de frugivoria, e que es- sas restrições são principalmente modificadas por disponibili- dade/previsibilidade hídricas. Por fim, observamos que ambos os métodos filogenéticos testados tem desempenho igualmente bom para estimar taxas atuais, porém ambos falham em detectar a trajetória da diversificação quando as taxas de extinção variam no tempo. Essa tese contribui para o conhecimento de mecanis- mos bióticos e abióticos que afetam tanto a diversificação quanto a montagem de redes de interação, e também provê informações importantes acerca da confiabilidade das estimativas de taxas de diversificação advindas dos métodos atuais amplamente utilizados
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Gascuel, Fanny. "Processus d'émergence des patrons de diversité supra-spécifiques lors des radiations évolutives." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066124/document.
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Les radiations évolutives sont des phénomènes de diversification rapide, et une source majeure de la diversité biologique sur Terre. J'explore ici l'hypothèse selon laquelle les mécanismes écologiques et génétiques à la base des radiations évolutives structurent les patrons macroécologiques et macroévolutifs de diversité. Pour ce faire, j'analyse les prédictions de plusieurs modèles de radiation émergeant des dynamiques spatio-temporelles à l'échelle individuelle. Ces analyses montrent d'abord que la structuration spatiale est un facteur majeur de diversité et d'endémisme au sein des archipels océaniques, en raison d'interactions entre dispersion et spéciation allopatrique. L'intégration de la dynamique des paysages et des processus d'interactions compétitives révèle ensuite comment ces facteurs se combinent pour structurer la forme des arbres phylogénétiques, et notamment générer des arbres déséquilibrés et une décélération du tempo de branchement, souvent observés dans les phylogénies moléculaires. J'explore alors les mécanismes responsables de cette décélération. Je montre qu'elle reflète une diversité-dépendance négative du taux de spéciation, liée à une réduction de la persistance et différentiation écologique des nouvelles populations. Le taux d'extinction n'est lui pas influencé par la diversité, les extinctions étant ici surtout causées par une combinaison d'exclusion compétitive et d'hybridation d'espèces incipientes. Enfin, je mets en évidence l'importance, lors d'une crise d'extinction, de la topologie rangée des arbres phylogénétiques et de la distribution des extinctions sur les pertes de diversité phylogénétique, et donc sur le potentiel d'évolution futureEvolutionary radiations are phenomena of rapid diversification, and one of the major sources of biodiversity on Earth. Here, I explore the hypothesis that ecological and genetic mechanisms underpinning evolutionary radiations structure macroecological and macroevolutionary patterns of diversity. To this end, I analyse the predictions of several models in which radiations emerge from spatio-temporal dynamics at the scale of the individual. These analyses first show that spatial structure is a major driver of diversity and endemism on oceanic archipelagos due to interactions between dispersal and allopatric speciation. Second, by integrating landscape dynamics and the processes of competitive interactions, I reveal how these factors combine to shape phylogenetic trees, and in particular to beget trees that are unbalanced and exhibit a deceleration in branching tempo, which is often observed on molecular phylogenies. I then explore the mechanisms responsible for this deceleration. I show that it reflects a negative diversity-dependence of the speciation rate, itself linked to a reduction in the persistence and ecological differentiation of new populations. The extinction rate is, on the other hand, uninfluenced by species diversity, extinctions being here mainly caused by a combinaison of competitive exclusion and hybridization of incipient species. Finally, I show that during mass extinctions the ranked topology of phylogenetic trees and the distribution of extinctions among the tips have a strong impact on the loss of phylogenetic diversity, and hence on the potential for future evolution
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Bokma, F. (Folmer). "Why most birds are small – a macro-ecological approach to the evolution of avian body size." Doctoral thesis, University of Oulu, 2004. http://urn.fi/urn:isbn:9514273451.
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Abstract There are more small-bodied species of birds than those having large bodies. Generally, and relative to occurrance in any one place, small-bodied species also contain more individuals than large-bodied species. The same patterns have been documented for several groups of higher organisms for example, snakes, flowering plants and mammals, which suggests that there exists a general reason "why", which applies to other groups of species as well as to birds. This thesis attempts to identify this reason. In the first place, it is possible that most species happened to become small-bodied by chance. Simulations of neutral body-size evolution indicate however that the observed bias towards small size is stronger than that accounted for by neutral evolution. Then, the most plausible explanation for why most species are small is that small-bodied species speciate faster. However, statistical analyses accounting for historical relatedness of present-day species indicate no relation between body size and the rate of speciation. Finally, instead of little by little, the dominance of small species may have arisen suddenly, when approximately 65 million years ago (presumably) a large meteorite hit the earth, causing mass extinctions. However, analysis of body sizes and genetic differences of extant species reveals that while avian species numbers were approximately halved, the catastrophe affected small and large species equally. Thus, the reason why most species are small does not seem to be due to differential rates of speciation or extinction. Instead, the cause appears to be in the tempo and mode of evolution. It was found by analysis of extant species' body size that probably most differences in body size between species arise at the moment of speciation. Differences between small-bodied species are smaller than between large-bodied species and probably this difference also has its origin at the moment of speciation. Consequently, groups of small species stay small whereas groups of large species are more variable in body size, so that in the end most species are smallTiivistelmä Maailman noin 10 000 lintulajin joukossa pienikokoisia lajeja on enemmän kuin suurikokoisia. Yleensä pienkokoiset lajit ovat myös yksilömääriltään suurempia kuin samalla paikalla esiintyvät suurikokoiset lajit. Koska sama ilmiö on havaittu monissa muissa suurissa eliöryhmissä (esim. nisäkkäät, käärmeet ja kukkakasvit), on ilmeistä, että on olemassa yhteinen syy, joka pätee niin linnuissa kuin muissakin eliöryhmissä. Tämän väitöskirjan tavoite on selvittää, mikä tämä yhteinen syy voisi olla. Ensinnäkin on mahdollista, että suurin osa lajeista on kehittynyt pienikokoisiksi aivan sattumalta. Ruumiin koon evoluution simulaatiot kuitenkin osoittavat, että on hyvin epätodennäköistä, että neutraali evoluutio olisi johtanut pienikokoisten lajien suuriin määrään havaitussa määrin. Toinen mahdollinen selitys ilmiölle on, että pienikokoiset lajit lajiutuvat nopeammin. Tilastolliset analyysit, jotka ottavat huomioon nykyisin elävien lajien sukulaisuussuhteet, osoittavat ettei ruumin koon ja lajiutumisen vauhdin välillä ole yhteyttä. Kolmas mahdollinen selitys pienikokoisten lajien suurelle määrällä on historiallinen. On mahdollista, että pienikokoisten lajien suhteellisen suuri määrä syntyi nopeasti noin 65 miljoonaa vuotta sitten tapahtuneen massasukupuuton seurauksena, joka fossiiliaineiston perusteella kohdistui erityisesti suurikokoisiin maaeläimiin (esimerkiksi dinosauruksiin). Vertaileva analyysi nykyään elävien lintulajien ruumiin koosta ja geneettisistä eroista osoittaa, että vaikka suuri osa lintulajeista hävisi massasukupuutossa, tämä katastrofi karsi lajeja riippumatta niiden ruumiin koosta. Näyttää siis siltä, etteivät erot lajiutumisen tai sukupuuttojen esiintymisessä selitä sitä, että suurin osa lajeista on pienikokoisia. Tämän tutkimuksen tulosten perusteella syy näyttäisi sen sijaan olevan ruumiin koon kehityksen vauhdissa ja siinä tavassa, jolla kehitys yleensä etenee. Analyysi nykyisten lajien ruumiin koosta paljasti, että suurin osa eroista lajien välillä syntyy (evolutiiviessa aikataulussa) suhteellisen nopeasti lajiutumistapahtuman yhteydessä (punktualismi) eikä vähitellen pitkien aikojen kuluessa (gradualismi), kuten yleensä oletetaan. Kehityslinjojen sisällä pienikokoisten lajien väliset erot ruumiin koossa olivat pienempiä kuin isokokoisten lajien väliset erot - ja todennäköisesti myöskin tämä ero syntyy lajiutumisen yhteydessä. Tämä johtaa evoluution kuluessa tilanteeseen, että alunperin pienikokoisista lajeista kehittyneet lajit ovat myös pienikokoisia, kun taas isokokoisten lajien kehityslinjoissa on nähtävissä huomattavasti paljon enemmän vaihtelua ruumiin koossa. Näiden seurauksena eliöstöissä suurin osa lajeista lopulta on pienikokoisia
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Stadler, Tanja [Verfasser]. "Evolving trees : models for speciation and extinction in phylogenetics / Tanja Stadler." 2008. http://d-nb.info/992078377/34.
Full textBooks on the topic "Speciation and extinction"
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Esler, Karen J., Anna L. Jacobsen, and R. Brandon Pratt. Evolution and Diversity. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198739135.003.0005.
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As mediterranean-type climate (MTC) regions emerged and expanded, species from the regional pool colonized and persisted in these new climate regions. In general, taxa were derived from a few types of historical ‘geoflora’ communities: temperate forest, subtropical and tropical, and semi-arid or arid. Some of the taxa within modern mediterranean-type vegetation represent relatively ancient relict taxa that pre-date the emergence of mediterranean-type drivers. Other lineages underwent subsequent speciation, resulting in the evolution of new MTC region-specific taxa, including the production of many new species through evolutionary radiations. Low extinction rates associated with historically stable climate and limited recent geological activity might explain the high diversity found in some MTC regions, while in regions with more topographical variation the ability of species to move across elevation gradients has been suggested also to have allowed species to be buffered from climatic changes that may otherwise have led to extinctions.
Book chapters on the topic "Speciation and extinction"
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Suzuki, Takao K., Motomu Matsui, Sira Sriswasdi, and Wataru Iwasaki. "Lifestyle Evolution Analysis by Binary-State Speciation and Extinction (BiSSE) Model." In Methods in Molecular Biology, 327–42. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2691-7_16.
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Bennett, Peter M., Ian P. F. Owens, and Jonathan E. M. Baillie. "The History and Ecological Basis of Extinction and Speciation in Birds." In Biotic Homogenization, 201–22. Boston, MA: Springer US, 2001. http://dx.doi.org/10.1007/978-1-4615-1261-5_10.
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Matzke, Nicholas J. "Science Without Species: Doing Science with Tree-Thinking." In Speciesism in Biology and Culture, 47–61. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-99031-2_3.
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AbstractThe focus of this volume is speciesism. While the concepts of species and speciation remain the focus of a great deal of research, it is worth exploring how in recent decades evolutionary biology has, in several ways, moved away from species as the key unit of analysis of biological questions. I begin by outlining how phylogenetic comparative methods have become essential methodological tools in statistical analyses of relationships between traits. Species are not statistically independent observations, because the reality is that they are related, genetically and statistically, on a phylogenetic tree. Phylogeny also plays a key role in modern analyses of spatial patterns in biodiversity, and in fact relying on phylogenetic biodiversity measures can avoid a number of problems created by attempting to impose a uniform species rank across different continents and clades. Similarly, a major challenge in modern studies of diversification and extinction concerns the units of analysis and how they are defined and recognized. Both “genus” and “species” are human-defined ranks imposed on the phylogenetic tree. The phylogenetic tree is the more fundamental reality that is produced by the macroevolutionary process, and it could include every level of gradation of genetic and morphological divergence. Once ranks are imposed upon it, a variety of methodological problems are created as scientists attempt to make these ranks standardized and comparable across different datasets and timescales. I outline how phylogenetic thinking might help provide a solution. I conclude with other examples where cutting-edge science is done with phylogenies without much need of the “species” rank—for example, in the battle against Covid-19.
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"Speciation and extinction." In Evolutionary Game Theory, Natural Selection, and Darwinian Dynamics, 231–74. Cambridge University Press, 2005. http://dx.doi.org/10.1017/cbo9780511542633.009.
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Ricklefs, Robert E. "Speciation, extinction and diversity." In Speciation and Patterns of Diversity, 257–77. Cambridge University Press, 2001. http://dx.doi.org/10.1017/cbo9780511815683.015.
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Fowler, Charles W. "Selective extinction and speciation." In Systemic Management, 55–77. Oxford University Press, 2009. http://dx.doi.org/10.1093/acprof:oso/9780199540969.003.0003.
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Wool, David. "Speciation, Extinction of Species and Phylogeny." In The Driving Forces of Evolution, 291–308. CRC Press, 2006. http://dx.doi.org/10.1201/b10758-23.
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"Speciation, Extinction of Species and Phylogeny." In The Driving Forces of Evolution, 291–308. Science Publishers, 2006. http://dx.doi.org/10.1201/b10758-27.
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"BIOGEOGRAPHICAL PROCESSES I: SPECIATION, DIVERSIFICATION, AND EXTINCTION." In Fundamentals of Biogeography, 26–51. Routledge, 2004. http://dx.doi.org/10.4324/9780203356586-11.
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Cadotte, Marc W., and T. Jonathan Davies. "Speciation, Extinction, and the Distribution of Phylogenetic Diversity." In Phylogenies in Ecology. Princeton University Press, 2016. http://dx.doi.org/10.23943/princeton/9780691157689.003.0008.
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This chapter examines the use of phylogenetic methods to explain macroevolutionary trends in speciation, extinction, and the distribution of phylogenetic diversity across space and through time. The diversity of life is unevenly distributed across the globe. Species richness tends to be higher at lower latitudes and elevations, and the distribution of life forms also varies across space. For example, Foster's rule suggests that on islands small species evolve to become bigger, while large species evolve to become smaller. Equally, the distribution of evolutionary history shows large spatial variation, reflecting the histories of speciation, extinction, and dispersal. This chapter first considers how large, global phylogenies make it possible to map the distribution of phylogenetic diversity and develop a conservation strategy to maximize coverage of the tree of life. It then discusses the variation in diversification across spatiotemporal gradients and shows that phylogenetic diversity covaries significantly with taxonomic richness.
Conference papers on the topic "Speciation and extinction"
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Warnock, Rachel C. M. "A PHYLOGENETIC PERSPECTIVE TO ESTIMATING SPECIATION AND EXTINCTION RATES FROM STRATIGRAPHIC RANGES." In GSA Annual Meeting in Indianapolis, Indiana, USA - 2018. Geological Society of America, 2018. http://dx.doi.org/10.1130/abs/2018am-322811.
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Warnock, Rachel C. M., Daniele Silvestro, Alexandra Gavryushkina, and Tanja Stadler. "CLOSING THE GAP BETWEEN PALEONTOLOGICAL AND NEONTOLOGICAL SPECIATION AND EXTINCTION RATE ESTIMATES." In GSA Annual Meeting in Seattle, Washington, USA - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017am-306182.
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James, Derek. "A comparison of speciation, extinction, and complexification in neuroevolution with and without selection pressure." In the 10th annual conference. New York, New York, USA: ACM Press, 2008. http://dx.doi.org/10.1145/1389095.1389196.
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Warnock, Rachel C. M., Tracy A. Heath, and Tanja Stadler. "ON THE IMPORTANCE OF INCOMPLETE SAMPLING IN PALAEONTOLOGICAL AND PHYLOGENETIC APPROACHES TO ESTIMATING SPECIATION AND EXTINCTION RATES." In GSA Annual Meeting in Seattle, Washington, USA - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017am-306236.
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Erba, Elisabetta. "MASS EXTINCTIONS AND GREATEST SPECIATIONS: THE EMERGENCE OF CALCAREOUS PHYTOPLANKTON IN THE EARLIEST MESOZOIC." In GSA Annual Meeting in Seattle, Washington, USA - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017am-302897.
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