scholarly journals Life History Divergence in Livebearing Fishes in Response to Predation: Is There a Microevolution to Macroevolution Barrier?

Diversity ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 179 ◽  
Author(s):  
Mark C. Belk ◽  
Spencer J. Ingley ◽  
Jerald B. Johnson

A central problem in evolutionary biology is to determine whether adaptive phenotypic variation within species (microevolution) ultimately gives rise to new species (macroevolution). Predation environment can select for trait divergence among populations within species. The implied hypothesis is that the selection resulting from predation environment that creates population divergence within species would continue across the speciation boundary such that patterns of divergence after speciation would be a magnified accumulation of the trait variation observed before speciation. In this paper, we test for congruence in the mechanisms of microevolution and macroevolution by comparing the patterns of life history divergence among three closely related species of the livebearer genus Brachyrhaphis (Poeciliidae), namely B. rhabdophora, B. roseni, and B. terrabensis. Within B. rhabdophora, populations occur in either predator or predator-free environments, and have been considered to be at a nascent stage of speciation. Sister species B. roseni and B. terrabensis are segregated into predator and predator-free environments, respectively, and represent a post-speciation comparison. Male and female size at maturity, clutch size, and offspring size (and to a lesser extent reproductive allocation) all diverged according to predation environment and differences were amplified through evolutionary time, i.e., across the speciation boundary. Variation observed among nascent species differentiated by predation environment is a good predictor of variation among established species differentiated by predation environment. We found no evidence for different processes or different levels of selection acting across the speciation boundary, suggesting that macroevolution in these species can be understood as an accumulation of micro-evolutionary changes.

Heredity ◽  
2021 ◽  
Author(s):  
Emily H. Le Sage ◽  
Sarah I. Duncan ◽  
Travis Seaborn ◽  
Jennifer Cundiff ◽  
Leslie J. Rissler ◽  
...  

Parasitology ◽  
1959 ◽  
Vol 49 (3-4) ◽  
pp. 374-386 ◽  
Author(s):  
R. J. Thomas

1. The life history of N. battus is described, and a comparative description of the life history of N. filicollis is given.2. The life histories of these two species are compared with those of N. spathiger and N. helvetianus, two closely related species, and are shown to follow the same basic pattern, with minor variations in timing which appear to be specific in nature, and not related to differences in culture methods or host species.3. The pathogenesis of Nematodirus species is discussed and related to the migration of larvae into the intestinal mucosa during development.


2006 ◽  
Vol 27 (3) ◽  
pp. 365-375 ◽  
Author(s):  
Delfi Sanuy ◽  
Christoph Leskovar ◽  
Neus Oromi ◽  
Ulrich Sinsch

AbstractDemographic life history traits were investigated in three Bufo calamita populations in Germany (Rhineland-Palatinate: Urmitz, 50°N; 1998-2000) and Spain (Catalonia: Balaguer, Mas de Melons, 41°N; 2004). We used skeletochronology to estimate the age as number of lines of arrested growth in breeding adults collected during the spring breeding period (all localities) and during the summer breeding period (only Urmitz). A data set including the variables sex, age and size of 185 males and of 87 females was analyzed with respect to seven life history traits (age and size at maturity of the youngest first breeders, age variation in first breeders, longevity, potential reproductive lifespan, median lifespan, age-size relationship). Spring and summer cohorts at the German locality differed with respect to longevity and potential reproductive lifespan by one year in favour of the early breeders. The potential consequences on fitness and stability of cohorts are discussed. Latitudinal variation of life history traits was mainly limited to female natterjacks in which along a south-north gradient longevity and potential reproductive lifespan increased while size decreased. These results and a review of published information on natterjack demography suggest that lifetime number of offspring seem to be optimized by locally different trade-offs: large female size at the cost of longevity in southern populations and increased longevity at the cost of size in northern ones.


2015 ◽  
Vol 282 (1815) ◽  
pp. 20151421 ◽  
Author(s):  
Göran Arnqvist ◽  
Ahmed Sayadi ◽  
Elina Immonen ◽  
Cosima Hotzy ◽  
Daniel Rankin ◽  
...  

The ultimate cause of genome size (GS) evolution in eukaryotes remains a major and unresolved puzzle in evolutionary biology. Large-scale comparative studies have failed to find consistent correlations between GS and organismal properties, resulting in the ‘ C -value paradox’. Current hypotheses for the evolution of GS are based either on the balance between mutational events and drift or on natural selection acting upon standing genetic variation in GS. It is, however, currently very difficult to evaluate the role of selection because within-species studies that relate variation in life-history traits to variation in GS are very rare. Here, we report phylogenetic comparative analyses of GS evolution in seed beetles at two distinct taxonomic scales, which combines replicated estimation of GS with experimental assays of life-history traits and reproductive fitness. GS showed rapid and bidirectional evolution across species, but did not show correlated evolution with any of several indices of the relative importance of genetic drift. Within a single species, GS varied by 4–5% across populations and showed positive correlated evolution with independent estimates of male and female reproductive fitness. Collectively, the phylogenetic pattern of GS diversification across and within species in conjunction with the pattern of correlated evolution between GS and fitness provide novel support for the tenet that natural selection plays a key role in shaping GS evolution.


Crustaceana ◽  
2021 ◽  
Vol 94 (4) ◽  
pp. 413-429
Author(s):  
Ye Ji Lee ◽  
Won Gyu Park

Abstract The population dynamics of Stenothoe valida Dana, 1852 were studied at Cheongsapo beach of Busan, Republic of Korea, from March 2019 to March 2020. Sampling was conducted once a month at low tide during spring tides. Specimens were grouped by the cephalic length at 0.025 mm intervals, and classified into four categories: females, ovigerous females, males and juveniles. The sex ratio, defined as females : total males + females, exceeded 0.5 during most of the study period. Brood size was significantly coupled with ovigerous female size. Two to four cohorts appeared at each study period. New cohorts occurred at almost every sampling except in the samples Jun-2, and Nov-2. Life span was estimated at 1-2 months. The juvenile ratio, the ratio of ovigerous females, and the recruitment rate estimated by FiSAT were commonly high in summer and winter. The life history of S. valida was not coupled with water temperature, but had a strong seasonal pattern.


Ecography ◽  
2016 ◽  
Vol 39 (11) ◽  
pp. 1056-1065 ◽  
Author(s):  
Christopher M. Tonra ◽  
Kimberly Sager-Fradkin ◽  
Peter P. Marra

2005 ◽  
Vol 62 (4) ◽  
pp. 730-737 ◽  
Author(s):  
David O Conover ◽  
Stephen A Arnott ◽  
Matthew R Walsh ◽  
Stephan B Munch

The potential of fishing mortality to cause rapid evolutionary changes in life history has received relatively little attention. By focusing only on ecological responses, standard fisheries theory and practice implicitly assume either that genetic influences on life history in the wild are negligible or that natural selection and adaptation is a slow process that can be effectively ignored. Lack of contrary evidence has allowed these assumptions to persist. Drawing upon >25 years of research on the Atlantic silverside (Menidia menidia), we show that adaptive genetic variation in many traits is finely tuned to natural variation in climate. Much of this variation is caused by a gradient in size-selective winter mortality and involves two- to threefold changes in physiological traits that influence population productivity. Many other species are now known to display similar patterns. Harvest experiments show that these traits can evolve rapidly in response to size-selective fishing. Hence, the pool of genotypes that code for life history traits is a highly dynamic property of populations. We argue that the lessons from Menidia are applicable to many exploited species where similar observations would be difficult to obtain and advocate greater use of species models to address fundamental questions in fishery science.


2018 ◽  
Author(s):  
Jacob W. Malcom ◽  
Thomas E. Juenger ◽  
Mathew A. Leibold

ABSTRACTBackgroundIdentifying the molecular basis of heritable variation provides insight into the underlying mechanisms generating phenotypic variation and the evolutionary history of organismal traits. Life history trait variation is of central importance to ecological and evolutionary dynamics, and contemporary genomic tools permit studies of the basis of this variation in non-genetic model organisms. We used high density genotyping, RNA-Seq gene expression assays, and detailed phenotyping of fourteen ecologically important life history traits in a wild-caught panel of 32Daphnia pulexclones to explore the molecular basis of trait variation in a model ecological species.ResultsWe found extensive phenotypic and a range of heritable genetic variation (~0 < H2< 0.44) in the panel, and accordingly identify 75-261 genes—organized in 3-6 coexpression modules—associated with genetic variation in each trait. The trait-related coexpression modules possess well-supported promoter motifs, and in conjunction with marker variation at trans- loci, suggest a relatively small number of important expression regulators. We further identify a candidate genetic network with SNPs in eight known transcriptional regulators, and dozens of differentially expressed genes, associated with life history variation. The gene-trait associations include numerous un-annotated genes, but also support several a priori hypotheses, including an ecdysone-induced protein and several Gene Ontology pathways.ConclusionThe genetic and gene expression architecture ofDaphnialife history traits is complex, and our results provide numerous candidate loci, genes, and coexpression modules to be tested as the molecular mechanisms that underlieDaphniaeco-evolutionary dynamics.


2001 ◽  
Vol 12 (3) ◽  
Author(s):  
Lauri Kaila ◽  
Bengt Bengtsson ◽  
Ivars Šulcs ◽  
Jari Junnilainen

The Elachista regificella complex (Elachistidae) is revised and considered to consist of three closely related species: E. regificella Sircom, presently only recorded from Great Britain, E. geminatella (Herrich-Schäffer), stat. rev. (= E. nieukerkeni Traugott-Olsen, syn. nov.) and E. tengstromi nom. nov. (= E. magnificella Tengström, 1848, nec Duponchel, 1843). The latter two species are widely distributed e.g. in Central Europe, the range of E. tengstromi extending to Japan. The species are diagnosed and illustrated. Life history records indicate that the species have, at least to some extent, different host plant preferences: Luzula sylvatica is recorded as the host plant of E. regificella and E. geminatella, of which the latter probably exploits other host plants as well. L. pilosa is the only known host plant of E. tengstromi in Europe, with further host plants recorded in Japan. Neotypes are designated for Elachista regificella Sircom and Poeciloptilia geminatella Herrich-Schäffer.


2018 ◽  
pp. 68-97
Author(s):  
Douglas S. Glazier

In this chapter, I show how clutch mass, offspring (egg) mass, and clutch size relate to body mass among species of branchiopod, maxillipod, and malacostracan crustaceans, as well as how these important life history traits vary among major taxa and environments independently of body size. Clutch mass relates strongly and nearly isometrically to body mass, probably because of physical volumetric constraints. By contrast, egg mass and clutch size relate more weakly and curvilinearly to body mass and vary in inverse proportion to one another, thus indicating a fundamental trade-off, which occurs within many crustacean taxa as well. In general, offspring (egg) size and number and their relationships to body mass appear to be more ecologically sensitive and evolutionarily malleable than clutch mass. The body mass scaling relationships of egg mass and clutch size show much more taxonomic and ecological variation (log-log scaling slopes varying from near 0 to almost 1 among major taxa) than do those for clutch mass, a pattern also observed in other animal taxa. The curvilinear body mass scaling relationships of egg mass and number also suggest a significant, size-related shift in how natural selection affects offspring versus maternal fitness. As body size increases, selection apparently predominantly favors increases in offspring size and fitness up to an asymptote, beyond which increases in offspring number and thus maternal fitness are preferentially favored. Crustaceans not only offer excellent opportunities for furthering our general understanding of life history evolution, but also their ecological and economic importance warrants further study of the various factors affecting their reproductive success.


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