Figure S1. PCA results showing morphospace occupation for Nsungwe Formation ampullariids when ana... more Figure S1. PCA results showing morphospace occupation for Nsungwe Formation ampullariids when analyzed separately from the comparison species set. Biplot indicates vectors of Total shell height (H); Total shell width (D), Aperture height (h), and Spire height (S)
In all species, geographic range is constrained by a combination of ecological and historical fac... more In all species, geographic range is constrained by a combination of ecological and historical factors. Ecological factors relate to the species' niche, its environmental or biotic limits in multidimensional space, while historical factors pertain to a species' ancestry, specifically the location at which a species evolved. Historical limitations are primary during speciation, while ecological factors control the subsequent expansion and contraction of species range. By assessing biogeographic changes during the lifespan of individual species, we can assess the relationship between paleobiogeography, paleoecology, and macroevolution. Quantitative paleobiogeographic analyses, especially those using GIS-based and phylogenetic methods, provide a framework to rigorously test hypotheses about the relationship between species ranges, biotic turnover, and paleoecology. These new tools provide a way to assess key questions about the co-evolution of life and earth. Changes in biogeogr...
Geographic ranges are estimated for brachiopod and bivalve species during the late Middle (mid-Gi... more Geographic ranges are estimated for brachiopod and bivalve species during the late Middle (mid-Givetian) to the middle Late (terminal Frasnian) Devonian to investigate range changes during the time leading up to and includ-ing the Late Devonian biodiversity crisis. Species ranges were predicted using GARP (Genetic Algorithm using Rule-set Prediction), a modeling program developed to predict fundamental niches of modern species. This method was applied to fossil species to examine changing ranges during a critical period of Earth’s history. Comparisons of GARP species distribution predictions with historical understanding of species occurrences indi-cate that GARP models predict accurately the presence of common species in some depositional settings. In addi-tion, comparison of GARP distribution predictions with species-range reconstructions from geographic information systems (GIS) analysis suggests that GARP modeling has the potential to predict species ranges more completely and t...
Biogeography is a scientific discipline with a rich intellectual heritage extending back at least... more Biogeography is a scientific discipline with a rich intellectual heritage extending back at least to the 18th century, and the discipline figured prominently in the development of ideas on evolution (see review in Lieberman, 2000). During the development of ideas on evolution, an important analogy was recognized between patterns of change in organisms across geographic space and patterns of change in organisms through geological time. For instance, Alfred Russel Wallace argued that, “If we now consider the geographical distribution of animals and plants upon the Earth, we shall find all the facts beautifully in accordance with, and readily explained by, the present hypothesis (Evolution). A country having species, genera, and whole families peculiar to it, will be the necessary result of its having been isolated for a long period…The phenomena of geological distribution are exactly analogous to those of geography. Closely related species are found associated in the same beds, and th...
The opportunity to reflect broadly on the accomplishments, prospects, and reach of a field may pr... more The opportunity to reflect broadly on the accomplishments, prospects, and reach of a field may present itself relatively infrequently. Each biennial meeting of the International Biogeography Society showcases ideas solicited and developed largely during the preceding year, by individuals or teams from across the breadth of the discipline. Here, we highlight challenges, developments, and opportunities in biogeography from that biennial synthesis. We note the realized and potential impact of rapid data accumulation in several fields, a renaissance for inter-disciplinary research, the importance of recognizing the evolution-ecology continuum across spatial and temporal scales and at different taxonomic, phylogenetic and functional levels, and re-exploration of classical assumptions and hypotheses using new tools. However, advances are taxonomically and geographically biased, and key theoretical frameworks await tools to handle, or strategies to simplify, the biological complexity seen in empirical systems. Current threats to biodiversity require unprecedented integration of knowledge and development of predictive capacity that may enable biogeography to unite its descriptive and hypothetico-deductive branches and establish a greater role within and outside academia.
Thin sedimentary interbeds within the Kirkpatrick Basalt (Jurassic) of Antarctica harbor exquisit... more Thin sedimentary interbeds within the Kirkpatrick Basalt (Jurassic) of Antarctica harbor exquisitely preserved 'soft-bodied' organisms that lived in and around shallow freshwater lakes of the time, some of which were hydrothermally influenced. In the hottest pools, associated with magmatic vents, unusual carbonates were apparently precipitated by Archaea extremophiles adapted to living near active lava flows. In cooler lakes more distant to the vents, fine siliciclastic sediments record other communities of spinicaudatan ("conchostracan") and notostracan crustaceans, larval insects, fishes, and ostracodes much of which may have been sustained by microbial mats, which are also well preserved in the deposits. Along the lake-edge, carbonized leaves, peat or coal, and silicified logs are often found in association with paleosols. Notably, evidence of carnivory, a primary taphonomic filter, is essentially lacking in these sediments. Exceptional preservation of non-biomineralized or lightly skeletonized organisms, therefore, reflects the original diversity of non-biomineralized or lightly skeletonized organisms present.
The use of ecological niche modeling (ENM) to estimate the geographic ranges of species is widely... more The use of ecological niche modeling (ENM) to estimate the geographic ranges of species is widely employed with modern fauna and is becoming more widespread in paleontology. Herein, field validation is utilized to assess the predictive accuracy of ENM methods for Paleozoic brachiopod species. This study represents the first field validation analysis of ENM methods in the fossil record. Previously published species distributions models for 8 Late Ordovician brachiopod species from the Cincinnati, Ohio region (United States) developed using GARP (Genetic Algorithm using Rule-set Prediction) were assessed for accuracy by comparing species occurrence data from a newly available set of 18 localities with the original species distribution models. Based on this data, the statistical significance of the original model set was assessed; 18 of the 22 original models were demonstrated to be statistically significant, based on field validation. Of the 140 individual species occurrences assessed, 60.8% were accurately predicted, 9.2% exhibited over prediction, and 30% exhibited under prediction. Accurate results were more common for species modeled from the greatest number of species occurrence points. The least accurate species models developed were for eurytopic species or those for which taxonomic affinities are unclear. Results indicate that with ample outcrop, well-defined stratigraphy, and sufficient fossil occurrence data, ENM methods could be successfully applied to many intervals in Earth history.
Thirty-two samples of submerged Nautilus macromphalus shells were recovered in 2008 from Lifou, L... more Thirty-two samples of submerged Nautilus macromphalus shells were recovered in 2008 from Lifou, Loyalty Islands in the South Pacific Ocean. Specimens were collected from carbonate-dominated sediment in water depths of 1-3 m. Some specimens were partly buried, whereas others rested on the seafloor. The majority of the specimens (66%) were recovered in a horizontal position, whereas 34% of the specimens were oriented vertically. Some specimens were pristine, with sharp color stripes and little encrustation by algae, cyanobacteria, or epizoans. The majority of specimens have substantial algal and cyanobacterial overcoats with some epizoans. In some specimens, the overcoats also trapped substantial amounts of carbonate sediment. Comparison of the 2008 collection of subtidal specimens to 43 beached Nautilus shells collected in 2002 from the same location reveals that the nearshore taphonomic pathways for drift cephalopod shells can be more complicated than published theoretical models suggest. Nautilus shells may or may not float directly to the beach. Shells not immediately deposited on the beach sink in the shallow water in a vertical position. Weight added by attached organisms and water infiltration, causes the submerged shells to eventually assume a horizontal position. Waves, currents, and bioturbation can then flip the shells over from side to side. Eventually submerged shells are buried, broken apart, or transported onto the beach. Beached shells that follow this taphonomic pathway have conspicuous algal coatings compared to those that simply float to shore. The Lifou subtidal population represents the first substantial modern externally shelled cephalopod collection from a shallow water environment to be analyzed to determine its taphonomic pathways. Conclusions from this analysis can be applied to nearshore deposits that contain externally shelled, fossilized cephalopods.
A new online resource, "The Digital Atlas of Ordovician Life: Exploring the Fauna of the Cincinna... more A new online resource, "The Digital Atlas of Ordovician Life: Exploring the Fauna of the Cincinnati Region" (www.OrdovicianAtlas.org), provides a tool for exploring the diversity, systematics, biogeography and stratigraphy of Late Ordovician fossils of the Cincinnati, Ohio region. This atlas has been developed using georeferenced specimen-based data that have been newly digitized as part of a collaborative project to mobilize species occurrence data for public use. The goals of this project are to digitize specimens of Late Ordovician (Katian) fossils from the type Cincinnatian Series that crop out in the Cincinnati, Ohio, USA region, develop a comprehensive online atlas of the fossils and develop outreach materials for K-16 (grade school through college) education and avocational paleontologists.
Phylogenetic biogeographic analysis of four brachiopod genera was used to uncover large-scale geo... more Phylogenetic biogeographic analysis of four brachiopod genera was used to uncover large-scale geologic drivers of Late Ordovician biogeographic differentiation in Laurentia. Previously generated phylogenetic hypotheses were converted into area cladograms, ancestral geographic ranges were optimized and speciation events characterized as via dispersal or vicariance, when possible. Area relationships were reconstructed using Lieberman-modified Brooks Parsimony Analysis. The resulting area cladograms indicate tectonic and oceanographic changes were the primary geologic drivers of biogeographic patterns within the focal taxa. The Taconic tectophase contributed to the separation of the Appalachian and Central basins as well as the two midcontinent basins, whereas sea level rise following the Boda Event promoted interbasinal dispersal. Three migration pathways into the Cincinnati Basin were recognized, which supports the multiple pathway hypothesis for the Richmondian Invasion.
Late Ordovician strata within the Cincinnati Basin record a mass faunal migration event during th... more Late Ordovician strata within the Cincinnati Basin record a mass faunal migration event during the C4 and C5 depositional sequences. The geographic source region for the invaders and the paleoceanographic conditions that facilitated dispersal into the Cincinnati Basin has previously been poorly understood. Using Parsimony Analysis of Endemicity, biogeographic relationships among Laurentian and Baltic basins were analyzed for each of the C1-C5 depositional sequences to identify dispersal paths. The results support multiple dispersal pathways, including three separate dispersal events between Baltica and Laurentia. Within Laurentia, results support dispersal pathways between areas north of the Transcontinental Arch into the western Midcontinent, between the Upper Mississippi Valley into the Cincinnati Basin, and between the peri-cratonic Scoto-Appalachian Basin and the Cincinnati Basin. These results support the hypothesis that invasive taxa entered the Cincinnati Basin via multiple dispersal pathways and that the equatorial Iapetus current facilitated dispersal of organisms from Baltica to Laurentia. Within Laurentia, surface currents and large storms moving from northeast to southwest likely influenced the dispersal of organisms. Larval states were characterized for the Richmondian invaders, and most invaders were found to have had planktotrophic planktic larvae. These self-feeding larvae have high dispersal potential, which-in conjunction with oceanographic and climatic conditions-enabled long-distance dispersal and interbasinal species migrations.
Figure S1. PCA results showing morphospace occupation for Nsungwe Formation ampullariids when ana... more Figure S1. PCA results showing morphospace occupation for Nsungwe Formation ampullariids when analyzed separately from the comparison species set. Biplot indicates vectors of Total shell height (H); Total shell width (D), Aperture height (h), and Spire height (S)
In all species, geographic range is constrained by a combination of ecological and historical fac... more In all species, geographic range is constrained by a combination of ecological and historical factors. Ecological factors relate to the species' niche, its environmental or biotic limits in multidimensional space, while historical factors pertain to a species' ancestry, specifically the location at which a species evolved. Historical limitations are primary during speciation, while ecological factors control the subsequent expansion and contraction of species range. By assessing biogeographic changes during the lifespan of individual species, we can assess the relationship between paleobiogeography, paleoecology, and macroevolution. Quantitative paleobiogeographic analyses, especially those using GIS-based and phylogenetic methods, provide a framework to rigorously test hypotheses about the relationship between species ranges, biotic turnover, and paleoecology. These new tools provide a way to assess key questions about the co-evolution of life and earth. Changes in biogeogr...
Geographic ranges are estimated for brachiopod and bivalve species during the late Middle (mid-Gi... more Geographic ranges are estimated for brachiopod and bivalve species during the late Middle (mid-Givetian) to the middle Late (terminal Frasnian) Devonian to investigate range changes during the time leading up to and includ-ing the Late Devonian biodiversity crisis. Species ranges were predicted using GARP (Genetic Algorithm using Rule-set Prediction), a modeling program developed to predict fundamental niches of modern species. This method was applied to fossil species to examine changing ranges during a critical period of Earth’s history. Comparisons of GARP species distribution predictions with historical understanding of species occurrences indi-cate that GARP models predict accurately the presence of common species in some depositional settings. In addi-tion, comparison of GARP distribution predictions with species-range reconstructions from geographic information systems (GIS) analysis suggests that GARP modeling has the potential to predict species ranges more completely and t...
Biogeography is a scientific discipline with a rich intellectual heritage extending back at least... more Biogeography is a scientific discipline with a rich intellectual heritage extending back at least to the 18th century, and the discipline figured prominently in the development of ideas on evolution (see review in Lieberman, 2000). During the development of ideas on evolution, an important analogy was recognized between patterns of change in organisms across geographic space and patterns of change in organisms through geological time. For instance, Alfred Russel Wallace argued that, “If we now consider the geographical distribution of animals and plants upon the Earth, we shall find all the facts beautifully in accordance with, and readily explained by, the present hypothesis (Evolution). A country having species, genera, and whole families peculiar to it, will be the necessary result of its having been isolated for a long period…The phenomena of geological distribution are exactly analogous to those of geography. Closely related species are found associated in the same beds, and th...
The opportunity to reflect broadly on the accomplishments, prospects, and reach of a field may pr... more The opportunity to reflect broadly on the accomplishments, prospects, and reach of a field may present itself relatively infrequently. Each biennial meeting of the International Biogeography Society showcases ideas solicited and developed largely during the preceding year, by individuals or teams from across the breadth of the discipline. Here, we highlight challenges, developments, and opportunities in biogeography from that biennial synthesis. We note the realized and potential impact of rapid data accumulation in several fields, a renaissance for inter-disciplinary research, the importance of recognizing the evolution-ecology continuum across spatial and temporal scales and at different taxonomic, phylogenetic and functional levels, and re-exploration of classical assumptions and hypotheses using new tools. However, advances are taxonomically and geographically biased, and key theoretical frameworks await tools to handle, or strategies to simplify, the biological complexity seen in empirical systems. Current threats to biodiversity require unprecedented integration of knowledge and development of predictive capacity that may enable biogeography to unite its descriptive and hypothetico-deductive branches and establish a greater role within and outside academia.
Thin sedimentary interbeds within the Kirkpatrick Basalt (Jurassic) of Antarctica harbor exquisit... more Thin sedimentary interbeds within the Kirkpatrick Basalt (Jurassic) of Antarctica harbor exquisitely preserved 'soft-bodied' organisms that lived in and around shallow freshwater lakes of the time, some of which were hydrothermally influenced. In the hottest pools, associated with magmatic vents, unusual carbonates were apparently precipitated by Archaea extremophiles adapted to living near active lava flows. In cooler lakes more distant to the vents, fine siliciclastic sediments record other communities of spinicaudatan ("conchostracan") and notostracan crustaceans, larval insects, fishes, and ostracodes much of which may have been sustained by microbial mats, which are also well preserved in the deposits. Along the lake-edge, carbonized leaves, peat or coal, and silicified logs are often found in association with paleosols. Notably, evidence of carnivory, a primary taphonomic filter, is essentially lacking in these sediments. Exceptional preservation of non-biomineralized or lightly skeletonized organisms, therefore, reflects the original diversity of non-biomineralized or lightly skeletonized organisms present.
The use of ecological niche modeling (ENM) to estimate the geographic ranges of species is widely... more The use of ecological niche modeling (ENM) to estimate the geographic ranges of species is widely employed with modern fauna and is becoming more widespread in paleontology. Herein, field validation is utilized to assess the predictive accuracy of ENM methods for Paleozoic brachiopod species. This study represents the first field validation analysis of ENM methods in the fossil record. Previously published species distributions models for 8 Late Ordovician brachiopod species from the Cincinnati, Ohio region (United States) developed using GARP (Genetic Algorithm using Rule-set Prediction) were assessed for accuracy by comparing species occurrence data from a newly available set of 18 localities with the original species distribution models. Based on this data, the statistical significance of the original model set was assessed; 18 of the 22 original models were demonstrated to be statistically significant, based on field validation. Of the 140 individual species occurrences assessed, 60.8% were accurately predicted, 9.2% exhibited over prediction, and 30% exhibited under prediction. Accurate results were more common for species modeled from the greatest number of species occurrence points. The least accurate species models developed were for eurytopic species or those for which taxonomic affinities are unclear. Results indicate that with ample outcrop, well-defined stratigraphy, and sufficient fossil occurrence data, ENM methods could be successfully applied to many intervals in Earth history.
Thirty-two samples of submerged Nautilus macromphalus shells were recovered in 2008 from Lifou, L... more Thirty-two samples of submerged Nautilus macromphalus shells were recovered in 2008 from Lifou, Loyalty Islands in the South Pacific Ocean. Specimens were collected from carbonate-dominated sediment in water depths of 1-3 m. Some specimens were partly buried, whereas others rested on the seafloor. The majority of the specimens (66%) were recovered in a horizontal position, whereas 34% of the specimens were oriented vertically. Some specimens were pristine, with sharp color stripes and little encrustation by algae, cyanobacteria, or epizoans. The majority of specimens have substantial algal and cyanobacterial overcoats with some epizoans. In some specimens, the overcoats also trapped substantial amounts of carbonate sediment. Comparison of the 2008 collection of subtidal specimens to 43 beached Nautilus shells collected in 2002 from the same location reveals that the nearshore taphonomic pathways for drift cephalopod shells can be more complicated than published theoretical models suggest. Nautilus shells may or may not float directly to the beach. Shells not immediately deposited on the beach sink in the shallow water in a vertical position. Weight added by attached organisms and water infiltration, causes the submerged shells to eventually assume a horizontal position. Waves, currents, and bioturbation can then flip the shells over from side to side. Eventually submerged shells are buried, broken apart, or transported onto the beach. Beached shells that follow this taphonomic pathway have conspicuous algal coatings compared to those that simply float to shore. The Lifou subtidal population represents the first substantial modern externally shelled cephalopod collection from a shallow water environment to be analyzed to determine its taphonomic pathways. Conclusions from this analysis can be applied to nearshore deposits that contain externally shelled, fossilized cephalopods.
A new online resource, "The Digital Atlas of Ordovician Life: Exploring the Fauna of the Cincinna... more A new online resource, "The Digital Atlas of Ordovician Life: Exploring the Fauna of the Cincinnati Region" (www.OrdovicianAtlas.org), provides a tool for exploring the diversity, systematics, biogeography and stratigraphy of Late Ordovician fossils of the Cincinnati, Ohio region. This atlas has been developed using georeferenced specimen-based data that have been newly digitized as part of a collaborative project to mobilize species occurrence data for public use. The goals of this project are to digitize specimens of Late Ordovician (Katian) fossils from the type Cincinnatian Series that crop out in the Cincinnati, Ohio, USA region, develop a comprehensive online atlas of the fossils and develop outreach materials for K-16 (grade school through college) education and avocational paleontologists.
Phylogenetic biogeographic analysis of four brachiopod genera was used to uncover large-scale geo... more Phylogenetic biogeographic analysis of four brachiopod genera was used to uncover large-scale geologic drivers of Late Ordovician biogeographic differentiation in Laurentia. Previously generated phylogenetic hypotheses were converted into area cladograms, ancestral geographic ranges were optimized and speciation events characterized as via dispersal or vicariance, when possible. Area relationships were reconstructed using Lieberman-modified Brooks Parsimony Analysis. The resulting area cladograms indicate tectonic and oceanographic changes were the primary geologic drivers of biogeographic patterns within the focal taxa. The Taconic tectophase contributed to the separation of the Appalachian and Central basins as well as the two midcontinent basins, whereas sea level rise following the Boda Event promoted interbasinal dispersal. Three migration pathways into the Cincinnati Basin were recognized, which supports the multiple pathway hypothesis for the Richmondian Invasion.
Late Ordovician strata within the Cincinnati Basin record a mass faunal migration event during th... more Late Ordovician strata within the Cincinnati Basin record a mass faunal migration event during the C4 and C5 depositional sequences. The geographic source region for the invaders and the paleoceanographic conditions that facilitated dispersal into the Cincinnati Basin has previously been poorly understood. Using Parsimony Analysis of Endemicity, biogeographic relationships among Laurentian and Baltic basins were analyzed for each of the C1-C5 depositional sequences to identify dispersal paths. The results support multiple dispersal pathways, including three separate dispersal events between Baltica and Laurentia. Within Laurentia, results support dispersal pathways between areas north of the Transcontinental Arch into the western Midcontinent, between the Upper Mississippi Valley into the Cincinnati Basin, and between the peri-cratonic Scoto-Appalachian Basin and the Cincinnati Basin. These results support the hypothesis that invasive taxa entered the Cincinnati Basin via multiple dispersal pathways and that the equatorial Iapetus current facilitated dispersal of organisms from Baltica to Laurentia. Within Laurentia, surface currents and large storms moving from northeast to southwest likely influenced the dispersal of organisms. Larval states were characterized for the Richmondian invaders, and most invaders were found to have had planktotrophic planktic larvae. These self-feeding larvae have high dispersal potential, which-in conjunction with oceanographic and climatic conditions-enabled long-distance dispersal and interbasinal species migrations.
This book is divided in two parts, the first of which shows how, beyond paleontology and systematics, macroevolutionary theories apply key insights from ecology and biogeography, developmental biology, biophysics, molecular phylogenetics, and even the sociocultural sciences to explain evolution in deep time. In the second part, the phenomenon of macroevolution is examined with the help of real life-history case studies on the evolution of eukaryotic sex, the formation of anatomical form and body-plans, extinction and speciation events of marine invertebrates, hominin evolution and species conservation ethics.
The book brings together leading experts, who explain pivotal concepts such as Punctuated Equilibria, Stasis, Developmental Constraints, Adaptive Radiations, Habitat Tracking, Turnovers, (Mass) Extinctions, Species Sorting, Major Transitions, Trends, and Hierarchies – key premises that allow macroevolutionary epistemic frameworks to transcend microevolutionary theories that focus on genetic variation, selection, migration and fitness.
Along the way, the contributing authors review ongoing debates and current scientific challenges; detail new and fascinating scientific tools and techniques that allow us to cross the classic borders between disciplines; demonstrate how their theories make it possible to extend the Modern Synthesis; present guidelines on how the macroevolutionary field could be further developed; and provide a rich view of just how it was that life evolved across time and space. In short, this book is a must-read for active scholars and, because the technical aspects are fully explained, it is also accessible for non-specialists.
Understanding evolution requires a solid grasp of above-population phenomena. Species are real biological individuals, and abiotic factors impact the future course of evolution. Beyond observation, when the explanation of macroevolution is the goal, we need both evidence and theory that enable us to explain and interpret how life evolves at the grand scale.
Museum collections of fossils, along with their associated locality data, provide millions of rec... more Museum collections of fossils, along with their associated locality data, provide millions of records representing data on the temporal and geographic distribution of species in deep time. However, to reach their greatest scientific and educational potential, these collections data need to be available on-line and in formats accessible to both professional scientists and the public. Recent efforts in our research group have focused on digitizing specimens of Late Ordovician (Katian) fossils from the Cincinnati, Ohio, USA region and developing outreach materials for K-16 education and avocational paleontologists. The initial year (2012-2013) of this NSF funded project focused on digitization (cataloging and georeferencing) of the 13,000 specimen collection housed at Ohio University. The digitization process resulted in a highly detailed, accurate digital data, which have been made publicly available via the iDigBio portal. By attaching accurately georeferenced latitude/longitude coordinates to each specimen, this collection has generated thousands of mappable data points to augment the digital biogeographic record. The second year of the project (2013-2014) focused on development and content generation for the website (www.OrdovicianAtlas.org). The atlas includes dedicated pages for common species and higher taxa in the Cincinnatian strata. Each species page includes paleoecological data, taxonomic details, stratigraphic occurrences, identification in hand sample information, and published descriptions on the species in question. The goal is to create content useful to both professional and avocational paleontologists. Currently, there are over 90 species and more than 250 higher taxa pages visible to the public. The third year of the project (2014-2015) will focus on developing interactive geographic maps of species and manipulable 3D renderings for common species. The collection has also been used to develop standards-aligned lesson plans for K-16 educators (grade school through college). These lessons utilize the well-exposed marine invertebrate fossils of the Cincinnati Arch region to explore concepts in diversity, ecology, and evolution with ties to modern ecosystem function.
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Papers by Alycia Stigall
This book is divided in two parts, the first of which shows how, beyond paleontology and systematics, macroevolutionary theories apply key insights from ecology and biogeography, developmental biology, biophysics, molecular phylogenetics, and even the sociocultural sciences to explain evolution in deep time. In the second part, the phenomenon of macroevolution is examined with the help of real life-history case studies on the evolution of eukaryotic sex, the formation of anatomical form and body-plans, extinction and speciation events of marine invertebrates, hominin evolution and species conservation ethics.
The book brings together leading experts, who explain pivotal concepts such as Punctuated Equilibria, Stasis, Developmental Constraints, Adaptive Radiations, Habitat Tracking, Turnovers, (Mass) Extinctions, Species Sorting, Major Transitions, Trends, and Hierarchies – key premises that allow macroevolutionary epistemic frameworks to transcend microevolutionary theories that focus on genetic variation, selection, migration and fitness.
Along the way, the contributing authors review ongoing debates and current scientific challenges; detail new and fascinating scientific tools and techniques that allow us to cross the classic borders between disciplines; demonstrate how their theories make it possible to extend the Modern Synthesis; present guidelines on how the macroevolutionary field could be further developed; and provide a rich view of just how it was that life evolved across time and space. In short, this book is a must-read for active scholars and, because the technical aspects are fully explained, it is also accessible for non-specialists.
Understanding evolution requires a solid grasp of above-population phenomena. Species are real biological individuals, and abiotic factors impact the future course of evolution. Beyond observation, when the explanation of macroevolution is the goal, we need both evidence and theory that enable us to explain and interpret how life evolves at the grand scale.
The initial year (2012-2013) of this NSF funded project focused on digitization (cataloging and georeferencing) of the 13,000 specimen collection housed at Ohio University. The digitization process resulted in a highly detailed, accurate digital data, which have been made publicly available via the iDigBio portal. By attaching accurately georeferenced latitude/longitude coordinates to each specimen, this collection has generated thousands of mappable data points to augment the digital biogeographic record.
The second year of the project (2013-2014) focused on development and content generation for the website (www.OrdovicianAtlas.org). The atlas includes dedicated pages for common species and higher taxa in the Cincinnatian strata. Each species page includes paleoecological data, taxonomic details, stratigraphic occurrences, identification in hand sample information, and published descriptions on the species in question. The goal is to create content useful to both professional and avocational paleontologists. Currently, there are over 90 species and more than 250 higher taxa pages visible to the public. The third year of the project (2014-2015) will focus on developing interactive geographic maps of species and manipulable 3D renderings for common species.
The collection has also been used to develop standards-aligned lesson plans for K-16 educators (grade school through college). These lessons utilize the well-exposed marine invertebrate fossils of the Cincinnati Arch region to explore concepts in diversity, ecology, and evolution with ties to modern ecosystem function.