scholarly journals From egg to adult: a developmental table of the ant Monomorium pharaonis

2020 ◽  
Author(s):  
Luigi Pontieri ◽  
Arjuna Rajakumar ◽  
Ab Matteen Rafiqi ◽  
Rasmus Stenbak Larsen ◽  
Ehab Abouheif ◽  
...  
Keyword(s):  
Developmental Plasticity ◽  
Phenotypic Diversity ◽  
Larval Instar ◽  
Evolutionary Process ◽  
Single Species ◽  
Evolutionary Developmental Biology ◽  
Evolutionary Transitions ◽  
Monomorium Pharaonis ◽  
Ideal System ◽  
Reproductive Division Of Labor

AbstractAnts exhibit remarkable phenotypic diversity and, with over approximately 16,000 species across 6 continents, represent one of the most evolutionarily and ecologically successful groups of animals. All ants are eusocial with a reproductive division of labor between morphologically and/or behaviourally distinct castes within a single species. This has made ants an ideal system to study core questions of eco-evo-devo (ecological evolutionary developmental biology) by highlighting the role of developmental plasticity, epigenetics, ancestral developmental potentials, modularity, and major evolutionary transitions in the evolutionary process. Yet, despite their importance for eco-evo-devo, no complete ontological series for an ant has been published to date. We therefore present the first developmental table in ants, from egg to adult, for the Myrmicine ant Monomorium pharaonis. We identified and characterized 17 embryonic stages, 3 larval instars, and prepupal/pupal development. We found that the majority of landmarks identified during embryogenesis in the fruitfly Drosophila melanogaster are conserved in M. pharaonis. Furthermore, we can morphologically discriminate reproductive larvae (queen and male-destined larvae) from one another after the 1st larval instar. Finally, this ontological series of M. pharaonis will serve as a blueprint for the generation of future ant developmental tables, which is key to understanding how the remarkable diversity in ants evolved.

scholarly journals Early Developmental Conditioning of Later Health and Disease: Physiology or Pathophysiology?

2014 ◽  
Vol 94 (4) ◽  
pp. 1027-1076 ◽  
Author(s):  
M. A. Hanson ◽  
P. D. Gluckman
Keyword(s):  
Animal Studies ◽  
Developmental Plasticity ◽  
Current Knowledge ◽  
Evolutionary Developmental Biology ◽  
Noncommunicable Disease ◽  
Normal Range ◽  
Physiological Processes ◽  
New Concepts ◽  
Health And Disease ◽  
Underlying Mechanisms

Extensive experimental animal studies and epidemiological observations have shown that environmental influences during early development affect the risk of later pathophysiological processes associated with chronic, especially noncommunicable, disease (NCD). This field is recognized as the developmental origins of health and disease (DOHaD). We discuss the extent to which DOHaD represents the result of the physiological processes of developmental plasticity, which may have potential adverse consequences in terms of NCD risk later, or whether it is the manifestation of pathophysiological processes acting in early life but only becoming apparent as disease later. We argue that the evidence suggests the former, through the operation of conditioning processes induced across the normal range of developmental environments, and we summarize current knowledge of the physiological processes involved. The adaptive pathway to later risk accords with current concepts in evolutionary developmental biology, especially those concerning parental effects. Outside the normal range, effects on development can result in nonadaptive processes, and we review their underlying mechanisms and consequences. New concepts concerning the underlying epigenetic and other mechanisms involved in both disruptive and nondisruptive pathways to disease are reviewed, including the evidence for transgenerational passage of risk from both maternal and paternal lines. These concepts have wider implications for understanding the causes and possible prevention of NCDs such as type 2 diabetes and cardiovascular disease, for broader social policy and for the increasing attention paid in public health to the lifecourse approach to NCD prevention.

scholarly journals Conflict and cooperation in eukaryogenesis: implications for the timing of endosymbiosis and the evolution of sex

2015 ◽  
Author(s):  
Arunas L Radzvilavicius ◽  
Neil W Blackstone
Keyword(s):  
Cell Fusion ◽  
Mitochondrial Gene ◽  
Evolutionary Process ◽  
Eukaryotic Cell ◽  
Evolutionary Transition ◽  
Evolutionary Transitions ◽  
Conflict And Cooperation ◽  
Conflict Mediation ◽  
Considerable Debate ◽  
History Of

The complex eukaryotic cell is a result of an ancient endosymbiosis and one of the major evolutionary transitions. The timing of key eukaryotic innovations relative to the acquisition of mitochondria remains subject to considerable debate, yet the evolutionary process itself might constrain the order of these events. Endosymbiosis entailed levels-of-selection conflicts, and mechanisms of conflict mediation had to evolve for eukaryogenesis to proceed. The initial mechanisms of conflict mediation were based on the pathways inherited from prokaryotic symbionts and led to metabolic homeostasis in the eukaryotic cell, while later mechanisms (e.g., mitochondrial gene transfer) contributed to the expansion of the eukaryotic genome. Perhaps the greatest opportunity for conflict arose with the emergence of sex involving whole-cell fusion. While early evolution of cell fusion may have affected symbiont acquisition, sex together with the competitive symbiont behaviour would have destabilised the emerging higher-level unit. Cytoplasmic mixing, on the other hand, would have been beneficial for selfish endosymbionts, capable of using their own metabolism to manipulate the life history of the host. Given the results of our mathematical modelling, we argue that sex represents a rather late proto- eukaryotic innovation, allowing for the growth of the chimeric nucleus and contributing to the successful completion of the evolutionary transition.

Units and levels of selection

2018 ◽  
Author(s):  
Samir Okasha
Keyword(s):  
Natural Selection ◽  
Kin Selection ◽  
Evolutionary Biology ◽  
Evolutionary Process ◽  
Levels Of Selection ◽  
Evolutionary Transitions ◽  
Individual Organism ◽  
Selection Processes ◽  
Hierarchical Levels ◽  
The Individual

In a standard Darwinian explanation, natural selection takes place at the level of the individual organism, i.e. some organisms enjoy a survival or reproduction advantage over others, which results in evolutionary change. In principle however, natural selection could operate at other hierarchical levels too, above and below that of the organism, for example the level of genes, cells, groups, colonies or even whole species. This possibility gives rise to the ‘levels of selection’ question in evolutionary biology. Group and colony-level selection have been proposed, originally by Darwin, as a means by which altruism can evolve. (In biology, ‘altruism’ refers to behaviour which entails a fitness cost to the individual so behaving, but benefits others.) Though this idea is still alive today, many theorists regard kin selection as a superior explanation for the existence of altruism. Kin selection arises from the fact that relatives share genes, so if an organism behaves altruistically towards its relatives, there is a greater than random chance that the beneficiary of the altruistic action will itself be an altruist. Kin selection is closely bound up with the ‘gene’s eye view’ of evolution, which holds that genes, not organisms, are the true beneficiaries of the evolutionary process. The gene’s eye approach to evolution, though heuristically valuable, does not in itself resolve the levels of selection question, because selection processes that occur at many hierarchical levels can all be seen from a gene’s eye viewpoint. In recent years, the levels of selection discussion has been re-invigorated, and subtly transformed, by the important new work on the ‘major evolutionary transitions’. These transitions occur when a number of free-living biological units, originally capable of surviving and reproducing alone, become integrated into a larger whole, giving rise to a new biological unit at a higher level of organization. Evolutionary transitions are intimately bound up with the levels of selection issue, because during a transition the potential exists for selection to operate simultaneously at two different hierarchical levels.

scholarly journals Morphology and behaviour: functional links in development and evolution

2011 ◽  
Vol 366 (1574) ◽  
pp. 2056-2068 ◽  
Author(s):  
Rinaldo C. Bertossa
Keyword(s):  
Phenotypic Diversity ◽  
Decisive Role ◽  
Evolutionary Developmental Biology ◽  
Form And Function ◽  
Biological Hierarchy ◽  
Object Of Study ◽  
And Function ◽  
Evo Devo ◽  
Versus Behaviour ◽  
Development And Evolution

Development and evolution of animal behaviour and morphology are frequently addressed independently, as reflected in the dichotomy of disciplines dedicated to their study distinguishing object of study (morphology versus behaviour) and perspective (ultimate versus proximate). Although traits are known to develop and evolve semi-independently, they are matched together in development and evolution to produce a unique functional phenotype. Here I highlight similarities shared by both traits, such as the decisive role played by the environment for their ontogeny. Considering the widespread developmental and functional entanglement between both traits, many cases of adaptive evolution are better understood when proximate and ultimate explanations are integrated. A field integrating these perspectives is evolutionary developmental biology (evo-devo), which studies the developmental basis of phenotypic diversity. Ultimate aspects in evo-devo studies—which have mostly focused on morphological traits—could become more apparent when behaviour, ‘the integrator of form and function’, is integrated into the same framework of analysis. Integrating a trait such as behaviour at a different level in the biological hierarchy will help to better understand not only how behavioural diversity is produced, but also how levels are connected to produce functional phenotypes and how these evolve. A possible framework to accommodate and compare form and function at different levels of the biological hierarchy is outlined. At the end, some methodological issues are discussed.

scholarly journals Large-scale diversification without genetic isolation in nematode symbionts of figs

2016 ◽  
Vol 2 (1) ◽  
pp. e1501031 ◽  
Author(s):  
Vladislav Susoy ◽  
Matthias Herrmann ◽  
Natsumi Kanzaki ◽  
Meike Kruger ◽  
Chau N. Nguyen ◽  
...  
Keyword(s):  
Genetic Divergence ◽  
Large Scale ◽  
Developmental Plasticity ◽  
Field Experiments ◽  
Single Species ◽  
Ecological Niches ◽  
Genetic Isolation ◽  
Remarkable Case ◽  
Alternative Phenotypes ◽  
Single Genotype

Diversification is commonly understood to be the divergence of phenotypes accompanying that of lineages. In contrast, alternative phenotypes arising from a single genotype are almost exclusively limited to dimorphism in nature. We report a remarkable case of macroevolutionary-scale diversification without genetic divergence. Upon colonizing the island-like microecosystem of individual figs, symbiotic nematodes of the genusPristionchusaccumulated a polyphenism with up to five discrete adult morphotypes per species. By integrating laboratory and field experiments with extensive genotyping of individuals, including the analysis of 49 genomes from a single species, we show that rapid filling of potential ecological niches is possible without diversifying selection on genotypes. This uncoupling of morphological diversification and speciation in fig-associated nematodes has resulted from a remarkable expansion of discontinuous developmental plasticity.

scholarly journals On the feasibility of saltational evolution

2018 ◽  
Author(s):  
Mikhail I. Katsnelson ◽  
Yuri I. Wolf ◽  
Eugene V. Koonin
Keyword(s):  
Evolutionary Biology ◽  
Fitness Landscape ◽  
Evolutionary Process ◽  
Analytic Solutions ◽  
Population Bottlenecks ◽  
Effective Population ◽  
Evolutionary Transitions ◽  
Evolutionary Changes ◽  
Saltational Evolution ◽  
As Stress

One of the key tenets of Darwin’s theory that was inherited by the Modern Synthesis of evolutionary biology is gradualism, that is, the notion that evolution proceeds gradually, via accumulation of “infinitesimally small” heritable changes 1,2. However, some of the most consequential evolutionary changes, such as, for example, the emergence of major taxa, seem to occur abruptly rather than gradually, as captured in the concepts of punctuated equilibrium 3,4 and evolutionary transitions 5,6. We examine a mathematical model of an evolutionary process on a rugged fitness landscape 7,8 and obtain analytic solutions for the probability of multi-mutational leaps, that is, several mutations occurring simultaneously, within a single generation in one genome, and being fixed all together in the evolving population. The results indicate that, for typical, empirically observed combinations of the parameters of the evolutionary process, namely, effective population size, mutation rate, and distribution of selection coefficients of mutations, the probability of a multi-mutational leap is low, and accordingly, their contribution to the evolutionary process is minor at best. However, such leaps could become an important factor of evolution in situations of population bottlenecks and elevated mutation rates, such as stress-induced mutagenesis in microbes or tumor progression, as well as major evolutionary transitions and evolution of primordial replicators.

scholarly journals Integrating ecological genomics and eco-evo-devo reveals multiple adaptive peaks in ant populations of the Arizona Sky Islands

2016 ◽  
Author(s):  
Marie-Julie Favé ◽  
Ehab Abouheif
Keyword(s):  
Fitness Landscape ◽  
Single Species ◽  
Evolutionary Developmental Biology ◽  
High Elevation ◽  
Climatic Changes ◽  
Temperature Adaptation ◽  
Sky Islands ◽  
Ecological Genomics ◽  
Ecological Gradient ◽  
Phenotypic Differences

Uncovering the genetic basis of adaptation is a great challenge facing evolutionary biologists. We ask where is the locus of adaptation from the perspective of ecological genomics (ecogen) and evolutionary developmental biology (evodevo). Ecogen focuses on identifying loci under selection between populations in different environments by scanning genome-wide patterns of genetic divergence, while evodevo focuses on candidate developmental regulatory genes and networks underlying phenotypic differences between species and higher taxa. We attempt to reconcile these different perspectives by studying the response of ant populations to past climate change on the Arizona Sky Islands - high elevation mountain ranges that represent a replicated natural experiment. We previously used an evodevo approach to show that adaptation to climatic changes in the Arizona Sky Islands in the ant species Monomorium emersoni occurred through repeated changes within the gene network underlying the development of alternative dispersal phenotypes: winged and wingless queens. Here, using an ecogen approach we uncovered several loci under positive selection that associate with habitat temperature. These temperatureassociated loci show a repeated increase in frequency following climatic changes on each of the Sky Islands. Surprisingly, gene flow between locations within a Sky Island is restricted by temperature adaptation along the ecological gradient and not by dispersal phenotype. This finding suggests that determination of winged and wingless queens may be developmentally plastic, and this plasticity may facilitate jumps between adaptive peaks on a fitness landscape. Integration of evodevo and ecogen reveals multiple adaptive peaks and predictability at multiple biological levels within a single species.

scholarly journals Evolution of the patella and patelloid in marsupial mammals

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9760
Author(s):  
Alice L. Denyer ◽  
Sophie Regnault ◽  
John R. Hutchinson
Keyword(s):  
Maximum Likelihood ◽  
Developmental Plasticity ◽  
Ct Scanning ◽  
Reconstruction Algorithm ◽  
Single Species ◽  
Character State ◽  
Sesamoid Bone ◽  
Future Studies ◽  
Marsupial Species ◽  
Complex Patterns

The musculoskeletal system of marsupial mammals has numerous unusual features beyond the pouch and epipubic bones. One example is the widespread absence or reduction (to a fibrous “patelloid”) of the patella (“kneecap”) sesamoid bone, but prior studies with coarse sampling indicated complex patterns of evolution of this absence or reduction. Here, we conducted an in-depth investigation into the form of the patella of extant marsupial species and used the assembled dataset to reconstruct the likely pattern of evolution of the marsupial patella. Critical assessment of the available literature was followed by examination and imaging of museum specimens, as well as CT scanning and histological examination of dissected wet specimens. Our results, from sampling about 19% of extant marsupial species-level diversity, include new images and descriptions of the fibrocartilaginous patelloid in Thylacinus cynocephalus (the thylacine or “marsupial wolf”) and other marsupials as well as the ossified patella in Notoryctes ‘marsupial moles’, Caenolestes shrew opossums, bandicoots and bilbies. We found novel evidence of an ossified patella in one specimen of Macropus rufogriseus (Bennett’s wallaby), with hints of similar variation in other species. It remains uncertain whether such ossifications are ontogenetic variation, unusual individual variation, pathological or otherwise, but future studies must continue to be conscious of variation in metatherian patellar sesamoid morphology. Our evolutionary reconstructions using our assembled data vary, too, depending on the reconstruction algorithm used. A maximum likelihood algorithm favours ancestral fibrocartilaginous “patelloid” for crown clade Marsupialia and independent origins of ossified patellae in extinct sparassodonts, peramelids, notoryctids and caenolestids. A maximum parsimony algorithm favours ancestral ossified patella for the clade [Marsupialia + sparassodonts] and subsequent reductions into fibrocartilage in didelphids, dasyuromorphs and diprotodonts; but this result changed to agree more with the maximum likelihood results if the character state reconstructions were ordered. Thus, there is substantial homoplasy in marsupial patellae regardless of the evolutionary algorithm adopted. We contend that the most plausible inference, however, is that metatherians independently ossified their patellae at least three times in their evolution. Furthermore, the variability of the patellar state we observed, even within single species (e.g. M. rufogriseus), is fascinating and warrants further investigation, especially as it hints at developmental plasticity that might have been harnessed in marsupial evolution to drive the complex patterns inferred here.

scholarly journals Extreme developmental instability associated with wing plasticity in pea aphids

2020 ◽  
Vol 287 (1937) ◽  
pp. 20201349
Author(s):  
Rachel E. Hammelman ◽  
Carrie L. Heusinkveld ◽  
Emily T. Hung ◽  
Alydia Meinecke ◽  
Benjamin J. Parker ◽  
...  
Keyword(s):  
Developmental Biology ◽  
Genetic Basis ◽  
Phenotypic Diversity ◽  
Evolutionary Developmental Biology ◽  
Developmental Instability ◽  
Wing Development ◽  
Alternative Phenotypes ◽  
Fitness Consequences ◽  
Pea Aphids ◽  
Widespread Phenomenon

A key focus of evolutionary developmental biology is on how phenotypic diversity is generated. In particular, both plasticity and developmental instability contribute to phenotypic variation among genetically identical individuals, but the interactions between the two phenomena and their general fitness impacts are unclear. We discovered a striking example of asymmetry in pea aphids: the presence of wings on one side and the complete or partial absence of wings on the opposite side. We used this asymmetric phenotype to study the connection between plasticity, developmental instability and fitness. We found that this asymmetric wing development (i) occurred equally on both sides and thus is a developmental instability; (ii) is present in some genetically unique lines but not others, and thus has a genetic basis; and (iii) has intermediate levels of fecundity, and thus does not necessarily have negative fitness consequences. We conclude that this dramatic asymmetry may arise from incomplete switching between developmental targets, linking plasticity and developmental instability. We suspect that what we have observed may be a more widespread phenomenon, occurring across species that routinely produce distinct, alternative phenotypes.

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