scholarly journals Growth patterns and life-history strategies in Placodontia (Diapsida: Sauropterygia)

2015 ◽  
Vol 2 (7) ◽  
pp. 140440 ◽  
Author(s):  
Nicole Klein ◽  
James M. Neenan ◽  
Torsten M. Scheyer ◽  
Eva Maria Griebeler
Keyword(s):  
Life History ◽  
Bone Tissue ◽  
Developmental Plasticity ◽  
Growth Models ◽  
Age At Onset ◽  
Growth Curves ◽  
Growth Patterns ◽  
Tissue Type ◽  
Life History Strategies ◽  
Long Bone

Placodontia is a clade of durophagous, near shore marine reptiles from Triassic sediments of modern-day Europe, Middle East and China. Although much is known about their primary anatomy and palaeoecology, relatively little has been published regarding their life history, i.e. ageing, maturation and growth. Here, growth records derived from long bone histological data of placodont individuals are described and modelled to assess placodont growth and life-history strategies. Growth modelling methods are used to confirm traits documented in the growth record (age at onset of sexual maturity, age when asymptotic length was achieved, age at death, maximum longevity) and also to estimate undocumented traits. Based on these growth models, generalized estimates of these traits are established for each taxon. Overall differences in bone tissue types and resulting growth curves indicate different growth patterns and life-history strategies between different taxa of Placodontia. Psephoderma and Paraplacodus grew with lamellar-zonal bone tissue type and show growth patterns as seen in modern reptiles. Placodontia indet. aff. Cyamodus and some Placodontia indet. show a unique combination of fibrolamellar bone tissue regularly stratified by growth marks, a pattern absent in modern sauropsids. The bone tissue type of Placodontia indet. aff. Cyamodus and Placodontia indet. indicates a significantly increased basal metabolic rate when compared with modern reptiles. Double lines of arrested growth, non-annual rest lines in annuli, and subcycles that stratify zones suggest high dependence of placodont growth on endogenous and exogenous factors. Histological and modelled differences within taxa point to high individual developmental plasticity but sexual dimorphism in growth patterns and the presence of different taxa in the sample cannot be ruled out.

scholarly journals Growth patterns, sexual dimorphism, and maturation modeled in Pachypleurosauria from Middle Triassic of central Europe (Diapsida: Sauropterygia)

Fossil Record ◽  
2018 ◽  
Vol 21 (1) ◽  
pp. 137-157 ◽  
Author(s):  
Nicole Klein ◽  
Eva Maria Griebeler
Keyword(s):  
Sexual Dimorphism ◽  
Bone Tissue ◽  
Sexual Maturation ◽  
Growth Curves ◽  
Growth Patterns ◽  
The Other ◽  
Tissue Type ◽  
Published Data ◽  
Adult Size ◽  
Germanic Basin

Abstract. Bone tissue, microanatomy, and growth are studied in humeri of the pachypleurosaurs Dactylosaurus from the early Anisian of Poland and of aff. Neusticosaurus pusillus from the Lettenkeuper (early Ladinian) of southern Germany. Histology and modeled growth curves are compared to already published data of other pachypleurosaurs. Therefore, we herein established growth curves for Anarosaurus from the middle Anisian of Winterswijk (the Netherlands) and for pachypleurosaurs from the Anisian/Ladinian of the Alpine Triassic (i.e., Neusticosaurus spp. and Serpianosaurus). Humeri of Dactylosaurus, Anarosaurus, and aff. N. pusillus, all from the Germanic Basin, usually display an inner ring of (pre-)hatchling bone tissue. In some samples this tissue is surrounded by a layer of perpendicularly oriented fine fibers, which could indicate the start of active locomotion for foraging or might be related to viviparity. However, pachypleurosaurs from the Alpine Triassic do not show this tissue. This in turn could be related to overall differences in the environments inhabited (Germanic Basin vs. Alpine Triassic). Histological comparison revealed distinct taxon-specific differences in microanatomy and bone tissue type between Anarosaurus on the one hand and Dactylosaurus and the Neusticosaurus–Serpianosaurus clade on the other hand. Microanatomical differences imply a different degree in secondary adaptation to an aquatic environment. Life-history traits derived histologically and obtained from modeling growth were in general rather similar for all studied pachypleurosaurs. Onset of sexual maturation was within the first third of life. Asymptotic ages (maximum life span) considerably exceeded documented and modeled ages at death in all pachypleurosaur taxa. All traits modeled (more or less) matched values seen in similar-sized extant reptiles. Growth curves revealed differences in growth and maturation strategies within taxa that could indicate sexual dimorphism expressed in different adult sizes and a different onset of sexual maturation. Differences in gender size and morphology is well documented for the Chinese pachypleurosaur Keichousaurus and for Neusticosaurus spp. from the Alpine Triassic. Birth-to-adult size ratios of herein studied pachypleurosaurs were consistent with those seen in other viviparous Sauropterygia, other viviparous extinct taxa as well as extant viviparous reptiles. Anarosaurus had the highest maximum growth rates of all pachypleurosaurs studied, which best conformed to those seen in today's similar-sized reptiles and is expected from its bone tissue type. The other pachypleurosaur taxa had lower rates than the average seen in similar-sized extant reptiles. We hypothesize from our data that the considerably higher asymptotic ages compared to ages at death, early onset of maturation compared to asymptotic age, and viviparity reflect that pachypleurosaurs lived in predator-dominated environments.

scholarly journals Irreversible impact of early thermal conditions: an integrative study of developmental plasticity linked to mobility in a butterfly species

2022 ◽  
Author(s):  
Anaïs Degut ◽  
Klaus Fischer ◽  
Martin Quque ◽  
François Criscuolo ◽  
Peter Michalik ◽  
...  
Keyword(s):  
Life History ◽  
Seasonal Changes ◽  
Developmental Plasticity ◽  
Thermal Conditions ◽  
Life History Strategies ◽  
Butterfly Species ◽  
Oxidative Markers ◽  
Displacement Capacity ◽  
Irreversible Effects ◽  
Cool Conditions

Within populations, phenotypic plasticity may allow adaptive phenotypic variation in response to selection generated by environmental heterogeneity. For instance, in multivoltine species, seasonal changes between and within generations may trigger morphological and physiological variation enhancing fitness under different environmental conditions. These seasonal changes may irreversibly affect adult phenotypes when experienced during development. Yet, the irreversible effects of developmental plasticity on adult morphology have rarely been linked to life-history traits even though they may affect different fitness components such as reproduction, mobility and self-maintenance. To address this issue, we raised larvae of Pieris napi butterflies under warm or cool conditions to subsequently compare adult performance in terms of reproduction performance (as assessed through fecundity), displacement capacity (as assessed through flight propensity and endurance) and self-maintenance (as assessed through the measurement of oxidative markers). As expected in ectotherms, individuals developed faster under warm conditions and were smaller than individuals developing under cool conditions. They also had more slender wings and showed a higher wing surface ratio. These morphological differences were associated with changes in the reproductive and flight performances of adults, as individuals developing under warm conditions laid fewer eggs and flew larger distances. Accordingly, the examination of their oxidative status suggested that individuals developing under warm conditions invested more strongly into self-maintenance than individuals developing under cool conditions (possibly at the expense of reproduction). Overall, our results indicate that developmental conditions have long-term consequences on several adult traits in butterflies. This plasticity likely acts on life history strategies for each generation to keep pace with seasonal variations and may facilitate acclimation processes in the context of climate change.

Comparing Early Life History Strategies of Pomatomus saltatrix: a Global Approach

1996 ◽  
Vol 47 (2) ◽  
pp. 365 ◽  
Author(s):  
F Juanes ◽  
JA Hare ◽  
AG Miskiewicz
Keyword(s):  
Life History ◽  
Early Life ◽  
Life History Traits ◽  
Early Life History ◽  
Growth Patterns ◽  
Life History Strategies ◽  
Eastern Coast ◽  
The South ◽  
Pomatomus Saltatrix ◽  
South Eastern

Pomatomus saltatrix (Pisces:Pomatomidae) is a highly migratory, continental-shelf species with a worldwide subtropical distribution including the eastern coast of North America, the Gulf of Mexico, Mediterranean Sea, Black Sea, north-western Africa, the eastern coast of South America, the south-eastern coast of South Africa, and the south-eastern and south-westem coasts of Australia. This paper summarizes available life history information from the different regions where P. saltatrix occurs, with a focus on the early life history. The basic physical oceanography of these regions is also reviewed to elucidate patterns in larval transport. Comparison of these populations suggests that there are commonalties: adults migrate to spawning grounds; eggs and larvae are typically advected along-shore to juvenile nursery habitats; juveniles recruit to inshore habitats at a similar size, and there they grow rapidly and are mainly piscivorous, feeding primarily on atherinids and engraulids. There are also a number of life history traits that are quite variable among populations: the number of annual reproductive peaks, the number of juvenile cohorts, adult growth patterns and reproductive parameters. Comparison of these life history patterns leads to several non-exclusive hypotheses as to the adaptive significance of variations in life history traits. The goal is to identify areas where more research is needed to assess the degree to which populations of a global species are adapted to their local environment.

scholarly journals Unearthing modes of climatic adaptation in underground storage organs across Liliales

2021 ◽  
Author(s):  
Carrie M. Tribble ◽  
Michael R May ◽  
Abigail Jackson-Gain ◽  
Rosana Zenil-Ferguson ◽  
Chelsea D. Specht ◽  
...  
Keyword(s):  
Life History ◽  
Comparative Method ◽  
Vascular Plant ◽  
Climatic Conditions ◽  
Tissue Type ◽  
Life History Strategies ◽  
Underground Storage ◽  
Phylogenetic Comparative Method ◽  
Storage Organs ◽  
Ecological Patterns

The evolution of major innovations in life history strategies (how organisms gather and store energy and reproduce) is a primary theme of biodiversity research. In one remarkable example of a life history innovation, certain plants --- geophytes --- retreat underground using underground storage organs (USOs), and thus survive extended periods of unfavorable conditions. Geophytes have evolved multiple times independently across all major vascular plant lineages. Even within closely related lineages, however, geophytes show impressive variation in the morphological modifications (i.e. 'types' of USOs) that allow them to survive underground. With all this variation, it is unclear to what extent geophytes with different USO morphologies have converged in climatic niche, or have evolved distinct niches. To test this hypothesis, we extended existing phylogenetic comparative method approaches to test for links between hierarchical discrete traits and adaptation to environmental variation. We inferred a phylogeny of 621 species of Liliales and used the phylogeny and analysis pipeline to test the relationship between underground morphologies and different adaptive optima of climate seasonality. Contrary to expectation, plants with the same USO type do not share climatic niches more than expected by chance, with the exception of root morphology, where modified roots are associated with lower temperature seasonality. These findings suggest that root tubers may be adaptations to different climatic conditions than other types of USOs. Thus, the tissue type and developmental origin of the structure may influence the way it mediates ecological relationships and draws into question the appropriateness of ascribing broad ecological patterns uniformly across geophytes. This work provides a new framework for testing adaptive hypotheses and for linking ecological patterns across morphologically varying taxa.

Mode of growth and life-history strategies of a Late Ordovician halysitid coral

1991 ◽  
Vol 65 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Dong-Jin Lee ◽  
Robert J. Elias
Keyword(s):  
Life History ◽  
Substrate Surface ◽  
Colony Growth ◽  
High Energy ◽  
Growth Patterns ◽  
Life History Strategies ◽  
Large Area ◽  
Physical Strength ◽  
Passive Flow ◽  
Vertical Growth Rate

The upper surface of the corallum ofCatenipora rubrawas often at or just above the sediment-water interface during life. The vertical growth rate was barely sufficient to keep pace with background sedimentation and possible subsidence of the corallum. Therefore, the colonies were in constant danger of being covered by influxes of sediment, especially during storms. This was compensated by the ability of polyps to respond to sedimentation events and by certain aspects of colony growth. Rapid regeneration following partial mortality involved budding of uninjured polyps and rejuvenation of damaged individuals, in some cases accompanied by a type of axial increase not previously known in tabulate corals. Rapid lateral expansion was possible because small, “immature” polyps could bud and grow in a reptant manner.Interconnected ranks of the cateniform corallum served to dam shifting sediment at the periphery of the colony. Lacunae within the colony were reservoirs for material that breached peripheral ranks and for sediment that settled on the ranks and was rejected by polyps or removed by passive flow. Polyps comprising the colony were distributed over a large area of the substrate surface, thereby decreasing the probability of complete mortality during sedimentation events and increasing the probability that a sufficient number of individuals would survive to ensure optimum regeneration. The corallum, anchored in the substrate and with sediment filling the lacunae, provided a broad, stable base during high-energy events.It remains to be established how widespread these growth patterns and strategies were among other corals with cateniform colonies, a form that appeared in many unrelated stocks. Most previous workers emphasized physical strength when considering functional morphology, following a tacit assumption that the corallum rose high above the substrate and was therefore susceptible to breakage during high-energy events. An understanding of the origin of cateniform patterns and the phylogeny of these corals requires knowledge of their modes of growth and life-history strategies, which were genetically as well as environmentally controlled.

scholarly journals Long Bone Histology and Growth Patterns in Ankylosaurs: Implications for Life History and Evolution

PLoS ONE ◽  
2013 ◽  
Vol 8 (7) ◽  
pp. e68590 ◽  
Author(s):  
Martina Stein ◽  
Shoji Hayashi ◽  
P. Martin Sander
Keyword(s):  
Life History ◽  
Growth Patterns ◽  
Bone Histology ◽  
Long Bone

scholarly journals A tale of two species: climate-competition tradeoffs shape range limits according to tree life-history strategies

2021 ◽  
Author(s):  
Jonathan Schurman ◽  
Pavel Janda ◽  
Milos Rydval ◽  
Martin Mikolas ◽  
Miroslav Svoboda ◽  
...  
Keyword(s):  
Life History ◽  
Interspecific Competition ◽  
Ring Width ◽  
Empirical Support ◽  
Growth Patterns ◽  
Range Limits ◽  
Life History Strategies ◽  
Range Limit ◽  
Lower Range ◽  
Cold Tolerant

Adapting for competitiveness versus climatic stress tolerance constitutes a primary trade-off differentiating tree life-history strategies. This tradeoff likely influences where species’ range-limits occur, but such links are data-demanding to study and key mechanisms lack empirical support. Using an exceptionally rich dendroecological network, we assessed spatial variation in climate and competition effects on Picea abies and Fagus sylvatica throughout the Carpathian Ecoregion. Ring width synchrony aided in diagnosing how the prevalence of resource-limited (competition) and sink-limited (climate) growth changes with altitude and community composition. Contrasting growth patterns towards respective upper and lower range limits of Fagus and Picea reflected tradeoffs between competitive vs. cold-tolerant strategies. Fagus performance declined with altitudinal increases in climate sensitivity, but improved under interspecific competition. Picea growth increased towards the species’ lower range limit, but declined under interspecific competition. Warmer temperatures likely benefit competitively stronger species at mid elevations and thus imply range reductions for alpine conifers.

scholarly journals Long bone histology and microanatomy of Placodontia (Diapsida: Sauropterygia)

2015 ◽  
Vol 84 (1) ◽  
pp. 59-S15 ◽  
Author(s):  
Nicole Klein ◽  
Alexandra Houssaye ◽  
James M. Neenan ◽  
Torsten M. Scheyer
Keyword(s):  
Metabolic Rate ◽  
Bone Tissue ◽  
Basal Metabolic Rate ◽  
Growth Rates ◽  
Developmental Plasticity ◽  
Medullary Cavity ◽  
Bone Histology ◽  
Tissue Type ◽  
Long Bones ◽  
Lamellar Bone

Placodontia, an enigmatic group of durophagous and in part heavily armoured animals, were members of Sauropterygia, the most diverse and successful group of Mesozoic marine reptiles. Microanatomy and histology of long bones of several armoured and non-armoured Placodontia were studied, covering most of their taxonomic breadth, to elucidate the paleoecology, physiology, and lifestyle of its members. Results reveal an unexpected and not phylogenetically or stratigraphically related disparity of microanatomical and histological features for the group. The non-armoured Paraplacodus and the heavily armoured Psephoderma grew with lamellar-zonal bone tissue type, which is typical for modern sauropsids. In the former, the tissue is nearly avascular surrounding a compacted medullary region, whereas in the latter, the lamellar-zonal bone tissue is vascularized framing a large open medullary cavity and a perimedullary region. Armoured Henodus and Placodontia indet. aff. Cyamodus as well as non-armoured Placodus exhibit a reduced medullary cavity and grew with highly vascularized plexiform to radiating fibro-lamellar bone. Several long bones of Placodontia indet. show circumferential fibro-lamellar bone and can be distinguished into two groups on the basis of microanatomical features. In addition, all bones that grew with fibro-lamellar bone show locally primary spongeous-like architecture and had secondarily widened primary osteons throughout the cortex, resulting in a secondarily spongeous tissue. The highly vascularized fibro-lamellar bone of these Placodontia indicates growth rates comparable to that of open marine ichthyosaurs. Differences in microanatomy and bone histology as expressed by a principal component analysis, thus clearly indicate different paleoecologies, including differences in lifestyle and swimming modes and capabilities in Placodontia. This would have reduced competition in the shallow marine environments of the Tethys and might be a key to their success and diversity. A certain developmental plasticity among the studied placodonts is interpreted as response to different environmental conditions as is obvious from inter- and intraspecific histological variation. Most striking is the difference in life history strategy in armoured Psephoderma and non-armoured Paraplacodus when compared to armoured Henodus, Placodontia indet. aff. Cyamodus, non-armoured Placodus, and Placodontia indet. Bone tissue of Psephoderma and Paraplacodus indicates low growth rates and a low basal metabolic rate, as many modern sauropsids have such as the marine iguana, whereas the others grew with extremely fast growth rates, more typical for birds and mammals, indicating an increased basal metabolic rate.

scholarly journals Bioenergetic Evolution Explains Prevalence of Low Nephron Number at Birth: Risk Factor for CKD

Kidney360 ◽  
2020 ◽  
Vol 1 (8) ◽  
pp. 863-879
Author(s):  
Robert L. Chevalier
Keyword(s):  
Risk Factor ◽  
Life History ◽  
Developmental Plasticity ◽  
Dna Methyltransferases ◽  
Life History Strategies ◽  
Evolutionary Analysis ◽  
Nephron Number ◽  
Regulatory Pathways ◽  
Maternal Undernutrition ◽  
Selection For

There is greater than tenfold variation in nephron number of the human kidney at birth. Although low nephron number is a recognized risk factor for CKD, its determinants are poorly understood. Evolutionary medicine represents a new discipline that seeks evolutionary explanations for disease, broadening perspectives on research and public health initiatives. Evolution of the kidney, an organ rich in mitochondria, has been driven by natural selection for reproductive fitness constrained by energy availability. Over the past 2 million years, rapid growth of an energy-demanding brain in Homo sapiens enabled hominid adaptation to environmental extremes through selection for mutations in mitochondrial and nuclear DNA epigenetically regulated by allocation of energy to developing organs. Maternal undernutrition or hypoxia results in intrauterine growth restriction or preterm birth, resulting in low birth weight and low nephron number. Regulated through placental transfer, environmental oxygen and nutrients signal nephron progenitor cells to reprogram metabolism from glycolysis to oxidative phosphorylation. These processes are modulated by counterbalancing anabolic and catabolic metabolic pathways that evolved from prokaryote homologs and by hypoxia-driven and autophagy pathways that evolved in eukaryotes. Regulation of nephron differentiation by histone modifications and DNA methyltransferases provide epigenetic control of nephron number in response to energy available to the fetus. Developmental plasticity of nephrogenesis represents an evolved life history strategy that prioritizes energy to early brain growth with adequate kidney function through reproductive years, the trade-off being increasing prevalence of CKD delayed until later adulthood. The research implications of this evolutionary analysis are to identify regulatory pathways of energy allocation directing nephrogenesis while accounting for the different life history strategies of animal models such as the mouse. The clinical implications are to optimize nutrition and minimize hypoxic/toxic stressors in childbearing women and children in early postnatal development.

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