Thomas J. Smith, Luke A. Parry, Frances S. Dunn, Russell J. Garwood
Ecosystem engineers can radically reshape ecosystems by modulating the availability of resources to other organisms through modifying either physical or biological aspects of the environment. The introduction or removal of ecosystem engineers from otherwise stable ecosystems can impact the diversity of co‐occurring species, such as driving local extinctions of native taxa. While these impacts are well established over ecological timescales for a wealth of taxa, the macroevolutionary implications of the onset of ecosystem engineering behaviours are less clear. Despite this uncertainty, ecosystem engineering has been implicated in several major transitions in Earth history including the appearance of extensive bioturbation during the Cambrian substrate revolution and associated Ediacaran–Cambrian turnover, and the Great Oxygenation Event. Whether ecosystem engineers are frequently associated with turnover and extinction in deep time is not known. Here we investigate this with an eco‐evolutionary simulation framework in which we assign lineages the ability to impact the fitness of co‐occurring taxa through phenotype–environment feedback. We explore numerous conditions, including how frequently such feedback occurs, and whether ecosystem engineers modify or create niches. We show that there is no general expected outcome from the introduction of ecosystem engineers. In a minority of runs, ecosystem engineering lineages completely dominate, rendering all others extinct, but in others they persist (but do not dominate), or die out. We suggest that ecosystem engineers have complex impacts, but possess the capacity to profoundly shape diversity, and it is appropriate to consider them alongside other exogenous extinction drivers in deep time.
{"title":"Exploring the macroevolutionary impact of ecosystem engineers using an individual‐based eco‐evolutionary simulation","authors":"Thomas J. Smith, Luke A. Parry, Frances S. Dunn, Russell J. Garwood","doi":"10.1111/pala.12701","DOIUrl":"https://doi.org/10.1111/pala.12701","url":null,"abstract":"Ecosystem engineers can radically reshape ecosystems by modulating the availability of resources to other organisms through modifying either physical or biological aspects of the environment. The introduction or removal of ecosystem engineers from otherwise stable ecosystems can impact the diversity of co‐occurring species, such as driving local extinctions of native taxa. While these impacts are well established over ecological timescales for a wealth of taxa, the macroevolutionary implications of the onset of ecosystem engineering behaviours are less clear. Despite this uncertainty, ecosystem engineering has been implicated in several major transitions in Earth history including the appearance of extensive bioturbation during the Cambrian substrate revolution and associated Ediacaran–Cambrian turnover, and the Great Oxygenation Event. Whether ecosystem engineers are frequently associated with turnover and extinction in deep time is not known. Here we investigate this with an eco‐evolutionary simulation framework in which we assign lineages the ability to impact the fitness of co‐occurring taxa through phenotype–environment feedback. We explore numerous conditions, including how frequently such feedback occurs, and whether ecosystem engineers modify or create niches. We show that there is no general expected outcome from the introduction of ecosystem engineers. In a minority of runs, ecosystem engineering lineages completely dominate, rendering all others extinct, but in others they persist (but do not dominate), or die out. We suggest that ecosystem engineers have complex impacts, but possess the capacity to profoundly shape diversity, and it is appropriate to consider them alongside other exogenous extinction drivers in deep time.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"24 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Head segments play a critical role in revealing the relationships within major arthropod groups but the accurate determination of their number and relationship is challenging because of the decoupling of dorsal tergites and ventral appendages. In recent decades, trilobites have been considered to have four pairs of cephalic appendages and, commonly, five dorsal segments, which has served as the basis for understanding euarthropod cephalic evolution. Based on multiple analytical techniques applied to well‐preserved soft‐bodied specimens of the Upper Ordovician olenid Triarthrus eatoni and middle Cambrian corynexochid Olenoides serratus, we argue that an additional pair of cephalic biramous appendages occurred just behind the antennae, indicating that trilobites had five pairs of cephalic appendages and six dorsally expressed segments. We propose that the mismatch between the four dorsal furrows and five ventral appendages in Olenoides may be reconciled by considering the morphology of the hypostome that marks the position of the antenna and the bifurcation of the first glabellar furrow that has two muscle attachment sites fused. The fusion of clustered attachment sites of the cephalic biramous appendages may have aided feeding ability by gathering the limb bases close to the mouth.
{"title":"New evidence for five cephalic appendages in trilobites and implications for segmentation of the trilobite head","authors":"Jin‐bo Hou, Melanie J. Hopkins","doi":"10.1111/pala.12723","DOIUrl":"https://doi.org/10.1111/pala.12723","url":null,"abstract":"Head segments play a critical role in revealing the relationships within major arthropod groups but the accurate determination of their number and relationship is challenging because of the decoupling of dorsal tergites and ventral appendages. In recent decades, trilobites have been considered to have four pairs of cephalic appendages and, commonly, five dorsal segments, which has served as the basis for understanding euarthropod cephalic evolution. Based on multiple analytical techniques applied to well‐preserved soft‐bodied specimens of the Upper Ordovician olenid <jats:italic>Triarthrus eatoni</jats:italic> and middle Cambrian corynexochid <jats:italic>Olenoides serratus</jats:italic>, we argue that an additional pair of cephalic biramous appendages occurred just behind the antennae, indicating that trilobites had five pairs of cephalic appendages and six dorsally expressed segments. We propose that the mismatch between the four dorsal furrows and five ventral appendages in <jats:italic>Olenoides</jats:italic> may be reconciled by considering the morphology of the hypostome that marks the position of the antenna and the bifurcation of the first glabellar furrow that has two muscle attachment sites fused. The fusion of clustered attachment sites of the cephalic biramous appendages may have aided feeding ability by gathering the limb bases close to the mouth.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"28 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142213362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aggregated clusters of acritarchs are relatively common among assemblages of organic‐walled microfossils, yet such associations have received relatively little attention. Here we report a new diversity of acritarch clusters from the early Cambrian Buen Formation of North Greenland. The aggregation patterns of four genera (Skiagia, Comasphaeridium, Asteridium and Synsphaeridium) are described together with their background population characteristics (presence of openings, inner bodies and overall disparity) in order to better understand the palaeobiology of these acritarchs. The majority of Skiagia clusters were found to be monospecific despite significant intraspecific variability, a pattern that is suggestive of a strong environmental influence on Skiagia morphologies and aggregation habits. Abundant small (<20 μm) Comasphaeridium vesicles were recovered in a broad range of chiefly monospecific clusters that are likely to have been formed under bloom conditions. A colonial habit is tentatively inferred from the tightly packed appearance of monogeneric Asteridium aggregates, and clearly evidenced by the highly conserved cellular structure of recovered Synsphaeridium clusters. A lack of excystment structures in Comasphaeridium and Asteridium vesicles suggest these taxa represent actively growing cells rather than resting cysts. Altogether, these findings shed new light on the diversity of cellular structures and lifestyles represented among Cambrian acritarchs, and illustrate a range of reproduction and defence strategies adopted by plankton in the face of novel environmental pressures.
{"title":"The palaeobiological significance of clustering in acritarchs: a case study from the early Cambrian of North Greenland","authors":"Elise Wallet, Ben J. Slater, Sebastian Willman","doi":"10.1111/pala.12722","DOIUrl":"https://doi.org/10.1111/pala.12722","url":null,"abstract":"Aggregated clusters of acritarchs are relatively common among assemblages of organic‐walled microfossils, yet such associations have received relatively little attention. Here we report a new diversity of acritarch clusters from the early Cambrian Buen Formation of North Greenland. The aggregation patterns of four genera (<jats:italic>Skiagia</jats:italic>, <jats:italic>Comasphaeridium</jats:italic>, <jats:italic>Asteridium</jats:italic> and <jats:italic>Synsphaeridium</jats:italic>) are described together with their background population characteristics (presence of openings, inner bodies and overall disparity) in order to better understand the palaeobiology of these acritarchs. The majority of <jats:italic>Skiagia</jats:italic> clusters were found to be monospecific despite significant intraspecific variability, a pattern that is suggestive of a strong environmental influence on <jats:italic>Skiagia</jats:italic> morphologies and aggregation habits. Abundant small (<20 μm) <jats:italic>Comasphaeridium</jats:italic> vesicles were recovered in a broad range of chiefly monospecific clusters that are likely to have been formed under bloom conditions. A colonial habit is tentatively inferred from the tightly packed appearance of monogeneric <jats:italic>Asteridium</jats:italic> aggregates, and clearly evidenced by the highly conserved cellular structure of recovered <jats:italic>Synsphaeridium</jats:italic> clusters. A lack of excystment structures in <jats:italic>Comasphaeridium</jats:italic> and <jats:italic>Asteridium</jats:italic> vesicles suggest these taxa represent actively growing cells rather than resting cysts. Altogether, these findings shed new light on the diversity of cellular structures and lifestyles represented among Cambrian acritarchs, and illustrate a range of reproduction and defence strategies adopted by plankton in the face of novel environmental pressures.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"6 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142213363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Raphael Moreno, Emma M. Dunne, Eudald Mujal, Alexander Farnsworth, Paul J. Valdes, Rainer R. Schoch
Temnospondyls had a remarkable worldwide distribution throughout the Triassic at a time of periodic arid climates, and were a stable component of Triassic terrestrial ecosystems. Given the postulated ancestral relationship between temnospondyls and modern lissamphibians it is pertinent to recognize that the group may have exhibited some degree of ecological resilience and adaptability. Despite this higher level of plasticity, temnospondyls might still have been susceptible to environmental and climate changes. Although fossil sites are distributed sporadically, we try to circumvent the present geographical and geological biases by combining actual fossil occurrences with environmental conditions derived from general circulation models. Here, we employ species distribution modelling to examine the palaeogeographic and palaeoclimatic distribution of European temnospondyls during the transition from Middle to Late Triassic. The model shows different suitable areas for temnospondyl habitats that give new potential insights on the biogeographic distribution patterns and dispersal potential. We suggest that the Central European Basin functioned as a focal point for Triassic temnospondyl diversification and spread. Moreover, this paper provides the first application of species distribution modelling for Triassic temnospondyls and aids in understanding their climatic niche occupation and evolution.
{"title":"Impact of environmental barriers on temnospondyl biogeography and dispersal during the Middle–Late Triassic","authors":"Raphael Moreno, Emma M. Dunne, Eudald Mujal, Alexander Farnsworth, Paul J. Valdes, Rainer R. Schoch","doi":"10.1111/pala.12724","DOIUrl":"https://doi.org/10.1111/pala.12724","url":null,"abstract":"Temnospondyls had a remarkable worldwide distribution throughout the Triassic at a time of periodic arid climates, and were a stable component of Triassic terrestrial ecosystems. Given the postulated ancestral relationship between temnospondyls and modern lissamphibians it is pertinent to recognize that the group may have exhibited some degree of ecological resilience and adaptability. Despite this higher level of plasticity, temnospondyls might still have been susceptible to environmental and climate changes. Although fossil sites are distributed sporadically, we try to circumvent the present geographical and geological biases by combining actual fossil occurrences with environmental conditions derived from general circulation models. Here, we employ species distribution modelling to examine the palaeogeographic and palaeoclimatic distribution of European temnospondyls during the transition from Middle to Late Triassic. The model shows different suitable areas for temnospondyl habitats that give new potential insights on the biogeographic distribution patterns and dispersal potential. We suggest that the Central European Basin functioned as a focal point for Triassic temnospondyl diversification and spread. Moreover, this paper provides the first application of species distribution modelling for Triassic temnospondyls and aids in understanding their climatic niche occupation and evolution.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"59 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142213364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Katherine A. Turk, Achim Wehrmann, Marc Laflamme, Simon A. F. Darroch
The evolutionary rise of powerful new ecosystem engineering impacts is thought to have played an important role in driving waves of biospheric change across the Ediacaran–Cambrian transition (ECT; c. 574–538 Ma). Among the most heavily cited of these is bioturbation (organism‐driven sediment disturbance) as these activities have been shown to have critical downstream geobiological impacts. In this regard priapulid worms are crucial; trace fossils thought to have been left by priapulan‐grade animals are now recognized as appearing shortly before the base of the Cambrian and represent some of the earliest examples of bed‐penetrative bioturbation. Understanding the ecosystem engineering impacts of priapulids may thus be key to reconstructing drivers of the ECT. However, priapulids are rare in modern benthic ecosystems, and thus comparatively little is known about the behaviours and impacts associated with their burrowing. Here, we present the early results of neoichnological experiments focused on understanding the ecosystem engineering impacts of priapulid worms. We observe for the first time a variety of new burrowing behaviours (including the formation of linked burrow networks and long in‐burrow residence times) hinting at larger ecosystem engineering impacts in this group than previously thought. Finally, we identify means by which these results may contribute to our understanding of tracemakers across the ECT, and the role they may have had in shaping the latest Ediacaran and earliest Cambrian biosphere.
{"title":"Priapulid neoichnology, ecosystem engineering, and the Ediacaran–Cambrian transition","authors":"Katherine A. Turk, Achim Wehrmann, Marc Laflamme, Simon A. F. Darroch","doi":"10.1111/pala.12721","DOIUrl":"https://doi.org/10.1111/pala.12721","url":null,"abstract":"The evolutionary rise of powerful new ecosystem engineering impacts is thought to have played an important role in driving waves of biospheric change across the Ediacaran–Cambrian transition (ECT; <jats:italic>c</jats:italic>. 574–538 Ma). Among the most heavily cited of these is bioturbation (organism‐driven sediment disturbance) as these activities have been shown to have critical downstream geobiological impacts. In this regard priapulid worms are crucial; trace fossils thought to have been left by priapulan‐grade animals are now recognized as appearing shortly before the base of the Cambrian and represent some of the earliest examples of bed‐penetrative bioturbation. Understanding the ecosystem engineering impacts of priapulids may thus be key to reconstructing drivers of the ECT. However, priapulids are rare in modern benthic ecosystems, and thus comparatively little is known about the behaviours and impacts associated with their burrowing. Here, we present the early results of neoichnological experiments focused on understanding the ecosystem engineering impacts of priapulid worms. We observe for the first time a variety of new burrowing behaviours (including the formation of linked burrow networks and long in‐burrow residence times) hinting at larger ecosystem engineering impacts in this group than previously thought. Finally, we identify means by which these results may contribute to our understanding of tracemakers across the ECT, and the role they may have had in shaping the latest Ediacaran and earliest Cambrian biosphere.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"110 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142213377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carmela Serio, Richard P. Brown, Marcus Clauss, Carlo Meloro
Mammals exhibit ecology‐related diversity in long bone morphology, revealing an ample spectrum of adaptations both within and between clades. Their occupation of unique ecological niches in postcranial morphology is thought to have occurred at different chronological phases in relation to abiotic factors such as climate and biotic interactions amongst major clades. Mammalian morphologies rapidly evolved throughout the Cenozoic, with several orders following different paths in locomotory adaptations. We assessed morphological variation in limb proportions for a rich sample of extant and fossil large mammalian clades (mainly carnivores and ungulates) to test associations with ecological adaptations and to identify temporal patterns of diversification. Phylogenetic relationships among species were incorporated into the analysis of limb bone proportions, showing significant morphological changes in relation to species substrate preference. Major climatic events appeared to have no temporal impact on patterns of morphological diversification, expressed as morphological disparity, in either clades or ecological groups. Linear stochastic differential equations supported a double‐wedge diversification model for limb proportions of carnivorous clades (‘Creodonta’ and Carnivora). The concomitant increase in morphological disparity throughout the Cenozoic for the orders Carnivora and Artiodactyla had a significative impact on the disparity of Perissodactyla supporting biotic interaction as primary driver of mammalian morphological diversification. Our findings challenge the classic idea of abiotic factors as primary driving forces in the evolution of postcranial morphologies for large terrestrial mammals, and propose clade competition as a key factor in temporal diversification.
{"title":"Morphological disparity of mammalian limb bones throughout the Cenozoic: the role of biotic and abiotic factors","authors":"Carmela Serio, Richard P. Brown, Marcus Clauss, Carlo Meloro","doi":"10.1111/pala.12720","DOIUrl":"https://doi.org/10.1111/pala.12720","url":null,"abstract":"Mammals exhibit ecology‐related diversity in long bone morphology, revealing an ample spectrum of adaptations both within and between clades. Their occupation of unique ecological niches in postcranial morphology is thought to have occurred at different chronological phases in relation to abiotic factors such as climate and biotic interactions amongst major clades. Mammalian morphologies rapidly evolved throughout the Cenozoic, with several orders following different paths in locomotory adaptations. We assessed morphological variation in limb proportions for a rich sample of extant and fossil large mammalian clades (mainly carnivores and ungulates) to test associations with ecological adaptations and to identify temporal patterns of diversification. Phylogenetic relationships among species were incorporated into the analysis of limb bone proportions, showing significant morphological changes in relation to species substrate preference. Major climatic events appeared to have no temporal impact on patterns of morphological diversification, expressed as morphological disparity, in either clades or ecological groups. Linear stochastic differential equations supported a double‐wedge diversification model for limb proportions of carnivorous clades (‘Creodonta’ and Carnivora). The concomitant increase in morphological disparity throughout the Cenozoic for the orders Carnivora and Artiodactyla had a significative impact on the disparity of Perissodactyla supporting biotic interaction as primary driver of mammalian morphological diversification. Our findings challenge the classic idea of abiotic factors as primary driving forces in the evolution of postcranial morphologies for large terrestrial mammals, and propose clade competition as a key factor in temporal diversification.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"275 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142213381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Emma J. Long, Gregory D. Edgecombe, Brett Clark, Callum Hatch, Alexander D. Ball, Xiaoya Ma
Trigonotarbida, an extinct order of spider‐like arachnids, were significant predators between the late Silurian and early Permian. Characterized by their segmented opisthosoma, clasp‐knife chelicera, and paired book lungs, they played a pivotal role in the formation of Early Devonian terrestrial ecosystems. However, the compression‐fossil or mould preservation of most trigonotarbids has been a limiting factor in understanding their fine morphology. Here, we re‐examine the mouthparts of Palaeocharinus, a trigonotarbid genus from the c. 408 Ma Rhynie chert of Scotland. Rhynie preserves the palaeocharinid trigonotarbids in three dimensions with extraordinary fidelity, offering detailed insights into their anatomy, feeding and hunting behaviours, and phylogenetic position. Here we present the first confocal laser scanning microscopy (CLSM) data for Palaeocharinus using three‐dimensional modelling to reconstruct the morphology of a tiered filtration apparatus, comprising a coarse outer mesh of interlacing plumose setae and a fine inner filter of pinnate setae. Together with the clasp‐knife action of the chelicera and mastication by the cheliceral teeth, Palaeocharinus emerges as a sophisticated terrestrial predator with a feeding mechanism resembling that of extant representatives of Pedipalpi (Amblypygi + Uropygi + Schizomida). Phylogenetic analyses with new and modified mouthpart characters affirm the placement of Trigonotarbida within Pantetrapulmonata (Aranaeae + Pedipalpi). This study provides insights into the evolutionary innovations that facilitated the diversification and proliferation of trigonotarbids in early terrestrial landscapes.
{"title":"Mouthpart morphology and feeding structures in the palaeocharinid trigonotarbids of the Rhynie chert: insights from comparisons to modern arachnids","authors":"Emma J. Long, Gregory D. Edgecombe, Brett Clark, Callum Hatch, Alexander D. Ball, Xiaoya Ma","doi":"10.1111/pala.12717","DOIUrl":"https://doi.org/10.1111/pala.12717","url":null,"abstract":"Trigonotarbida, an extinct order of spider‐like arachnids, were significant predators between the late Silurian and early Permian. Characterized by their segmented opisthosoma, clasp‐knife chelicera, and paired book lungs, they played a pivotal role in the formation of Early Devonian terrestrial ecosystems. However, the compression‐fossil or mould preservation of most trigonotarbids has been a limiting factor in understanding their fine morphology. Here, we re‐examine the mouthparts of <jats:italic>Palaeocharinus</jats:italic>, a trigonotarbid genus from the <jats:italic>c</jats:italic>. 408 Ma Rhynie chert of Scotland. Rhynie preserves the palaeocharinid trigonotarbids in three dimensions with extraordinary fidelity, offering detailed insights into their anatomy, feeding and hunting behaviours, and phylogenetic position. Here we present the first confocal laser scanning microscopy (CLSM) data for <jats:italic>Palaeocharinus</jats:italic> using three‐dimensional modelling to reconstruct the morphology of a tiered filtration apparatus, comprising a coarse outer mesh of interlacing plumose setae and a fine inner filter of pinnate setae. Together with the clasp‐knife action of the chelicera and mastication by the cheliceral teeth, <jats:italic>Palaeocharinus</jats:italic> emerges as a sophisticated terrestrial predator with a feeding mechanism resembling that of extant representatives of Pedipalpi (Amblypygi + Uropygi + Schizomida). Phylogenetic analyses with new and modified mouthpart characters affirm the placement of Trigonotarbida within Pantetrapulmonata (Aranaeae + Pedipalpi). This study provides insights into the evolutionary innovations that facilitated the diversification and proliferation of trigonotarbids in early terrestrial landscapes.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"23 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141942636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For many evolutionary biologists, fitness differences cause trait frequency changes in populations, and natural selection explains the evolution of adaptations. Treating fitness differences as a cause, however, is more scientific convention rather than decree, and analyses of the causes of natural selection potentially afford richer evolutionary explanations. Unfortunately, the historical assumptions that the complexities of development leave the origins of phenotypic variation unpredictable, and that ecological processes are idiosyncratic, have hindered detailed analysis of the developmental bases of natural selection. A poorly appreciated consequence is that explanations reliant on selection potentially mask particular causal patterns important in evolution. Here, using examples of environmental modification and regulation by organisms (‘niche construction’, a.k.a. ‘ecosystem engineering’), and developmental plastic responses to environmental conditions (‘phenotypic plasticity’), I will highlight how the development and activities of organisms create developmental biases that co‐determine the nature of the response to selection, in an often surprisingly well‐regulated manner. Niche construction biases the phenotypic variation exposed to selection, often generating axes of covariation with plastically expressed morphological traits. Taxonomically shared developmental mechanisms aggregate across populations to generate statistical regularities that are easy to miss because the developmental causes of fitness differences are not currently central to the study of evolution. Recent theory and experiments suggest that how organisms develop and what organisms do cause and strengthen the relationship between key traits and fitness, thereby part‐determining the characteristics of natural selection. The findings have implications for understanding parallel evolution, macroevolutionary trends and variation in evolvability.
{"title":"Understanding niche construction and phenotypic plasticity as causes of natural selection","authors":"Kevin Lala","doi":"10.1111/pala.12719","DOIUrl":"https://doi.org/10.1111/pala.12719","url":null,"abstract":"For many evolutionary biologists, fitness differences <jats:italic>cause</jats:italic> trait frequency changes in populations, and natural selection <jats:italic>explains</jats:italic> the evolution of adaptations. Treating fitness differences as a cause, however, is more scientific convention rather than decree, and analyses of the causes of natural selection potentially afford richer evolutionary explanations. Unfortunately, the historical assumptions that the complexities of development leave the origins of phenotypic variation unpredictable, and that ecological processes are idiosyncratic, have hindered detailed analysis of the developmental bases of natural selection. A poorly appreciated consequence is that explanations reliant on selection potentially mask particular causal patterns important in evolution. Here, using examples of environmental modification and regulation by organisms (‘niche construction’, a.k.a. ‘ecosystem engineering’), and developmental plastic responses to environmental conditions (‘phenotypic plasticity’), I will highlight how the development and activities of organisms create developmental biases that co‐determine the nature of the response to selection, in an often surprisingly well‐regulated manner. Niche construction biases the phenotypic variation exposed to selection, often generating axes of covariation with plastically expressed morphological traits. Taxonomically shared developmental mechanisms aggregate across populations to generate statistical regularities that are easy to miss because the developmental causes of fitness differences are not currently central to the study of evolution. Recent theory and experiments suggest that how organisms develop and what organisms do cause and strengthen the relationship between key traits and fitness, thereby part‐determining the characteristics of natural selection. The findings have implications for understanding parallel evolution, macroevolutionary trends and variation in evolvability.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"77 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141567338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
That the activities of organisms influence their surrounding ecological communities, and the environment, has long been appreciated by palaeontologists, as has the role of these activities on both ecological and evolutionary processes. Spillover effects extend the range of ecosystem‐engineering through ecological networks, generating network effects that because of their non‐trophic nature can be challenging to track. Moreover, the cumulative effect of organismal activities can persist far beyond the lifespan of individual organisms, producing ecological inheritances that influence macroecological and macroevolutionary dynamics. This contribution surveys macroevolutionary patterns arising from ecosystem engineering, their potential contribution to evolutionary radiations, and the significance of ecosystem engineering as a public good in the success of evolutionary innovations. Anecdotally, such activities appear to have made important contributions, but considerable work is required for more rigorous understanding. I describe two challenges: the need for palaeontologists to collect abundance data in a way that facilitates comparative study, and the importance of more robust models of ecological (not just trophic) networks involving multigraphs and hypergraphs.
{"title":"Macroevolutionary dynamics of ecosystem‐engineering and niche construction","authors":"Douglas H. Erwin","doi":"10.1111/pala.12718","DOIUrl":"https://doi.org/10.1111/pala.12718","url":null,"abstract":"That the activities of organisms influence their surrounding ecological communities, and the environment, has long been appreciated by palaeontologists, as has the role of these activities on both ecological and evolutionary processes. Spillover effects extend the range of ecosystem‐engineering through ecological networks, generating network effects that because of their non‐trophic nature can be challenging to track. Moreover, the cumulative effect of organismal activities can persist far beyond the lifespan of individual organisms, producing ecological inheritances that influence macroecological and macroevolutionary dynamics. This contribution surveys macroevolutionary patterns arising from ecosystem engineering, their potential contribution to evolutionary radiations, and the significance of ecosystem engineering as a public good in the success of evolutionary innovations. Anecdotally, such activities appear to have made important contributions, but considerable work is required for more rigorous understanding. I describe two challenges: the need for palaeontologists to collect abundance data in a way that facilitates comparative study, and the importance of more robust models of ecological (not just trophic) networks involving multigraphs and hypergraphs.","PeriodicalId":56272,"journal":{"name":"Palaeontology","volume":"4 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141567337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}