scholarly journals Evolution of floral diversity: genomics, genes and gamma

2017 ◽  
Vol 372 (1713) ◽  
pp. 20150509 ◽  
Author(s):  
Andre S. Chanderbali ◽  
Brent A. Berger ◽  
Dianella G. Howarth ◽  
Douglas E. Soltis ◽  
Pamela S. Soltis
Keyword(s):  
Morphological Diversity ◽  
Salient Feature ◽  
Flowering Plant ◽  
Developmental Genetics ◽  
Terrestrial Plants ◽  
Evolutionary Diversification ◽  
Floral Diversity ◽  
Evolutionary Consequences ◽  
Evo Devo ◽  
Genome Triplication

A salient feature of flowering plant diversification is the emergence of a novel suite of floral features coinciding with the origin of the most species-rich lineage, Pentapetalae. Advances in phylogenetics, developmental genetics and genomics, including new analyses presented here, are helping to reconstruct the specific evolutionary steps involved in the evolution of this clade. The enormous floral diversity among Pentapetalae appears to be built on a highly conserved ground plan of five-parted (pentamerous) flowers with whorled phyllotaxis. By contrast, lability in the number and arrangement of component parts of the flower characterize the early-diverging eudicot lineages subtending Pentapetalae. The diversification of Pentapetalae also coincides closely with ancient hexaploidy, referred to as the gamma whole-genome triplication, for which the phylogenetic timing, mechanistic details and molecular evolutionary consequences are as yet not fully resolved. Transcription factors regulating floral development often persist in duplicate or triplicate in gamma -derived genomes, and both individual genes and whole transcriptional programmes exhibit a shift from broadly overlapping to tightly defined expression domains in Pentapetalae flowers. Investigations of these changes associated with the origin of Pentapetalae can lead to a more comprehensive understanding of what is arguably one of the most important evolutionary diversification events within terrestrial plants. This article is part of the themed issue ‘Evo-devo in the genomics era, and the origins of morphological diversity’.

Amazing grass: developmental genetics of maize domestication

2005 ◽  
Vol 33 (6) ◽  
pp. 1502-1506 ◽  
Author(s):  
E. Vollbrecht ◽  
B. Sigmon
Keyword(s):  
Reverse Genetics ◽  
Population Genomics ◽  
Evolutionary Developmental Biology ◽  
Developmental Genetics ◽  
Crop Domestication ◽  
Modern Maize ◽  
Signatures Of Selection ◽  
Maize Domestication ◽  
Plant Form ◽  
Evo Devo

Crop plants were domesticated by prehistoric farmers through artificial selection to provide a means of feeding the human population. This article discusses the developmental genetics of crop domestication and improvement, including the historical framework and recent approaches in maize and other grasses. In many cases, selecting for a plant form that correlates with productivity involves controlling meristem activity. In the domestication of modern maize from its progenitor Zea mays ssp. parviglumis, QTL (quantitative trait loci) mapping, genetics and population genomics approaches have identified several genes that contain signatures of selection. Only a few genes involved in the derivation of the highly productive maize ear have been identified, including teosinte glume architecture1 and ramosa1. Future prospects hinge on forward and reverse genetics, as well as on other approaches from the developing discipline of evo-devo (evolutionary developmental biology).

Evolutionary developmental biology

2018 ◽  
Author(s):  
Ron Amundson
Keyword(s):  
Developmental Biology ◽  
Evolutionary Developmental Biology ◽  
Developmental Genetics ◽  
Comparative Biology ◽  
Embryological Development ◽  
Adult Form ◽  
The Core ◽  
Almost All ◽  
Evo Devo ◽  
Year 2000

Evolutionary developmental biology is the study of evolutionary change (called phylogeny) as it is revealed through the embryological development of individual organisms (called ontogeny). On this approach, the understanding of ontogeny contributes to our understanding of phylogeny, and vice versa. Evolutionary thinkers of the nineteenth century almost all held what may be called the core doctrine of evolutionary developmental biology: that in order to achieve a modification in the adult form, evolution must modify the embryological processes responsible for that form, so that an understanding of evolution requires an understanding of development. Evolutionary theory has no theoretical need for developmental views of evolution. Beginning around 1990 a series of discoveries and theoretical innovations in developmental genetics led to the reinvigoration of developmental approaches to evolution. Evolutionary developmental biology (‘evo-devo’ as it is now called) was inaugurated as a Division of the Society for Integrative and Comparative Biology in the year 2000.

scholarly journals Origin of animal multicellularity: precursors, causes, consequences—the choanoflagellate/sponge transition, neurogenesis and the Cambrian explosion

2017 ◽  
Vol 372 (1713) ◽  
pp. 20150476 ◽  
Author(s):  
Thomas Cavalier-Smith
Keyword(s):  
Connective Tissue ◽  
Photosynthetic Bacteria ◽  
Cell Structure ◽  
Morphological Diversity ◽  
Cambrian Explosion ◽  
Feeding Modes ◽  
Selection For ◽  
Evo Devo ◽  
Gastraea Theory ◽  
Bacterial Food

Evolving multicellularity is easy, especially in phototrophs and osmotrophs whose multicells feed like unicells. Evolving animals was much harder and unique; probably only one pathway via benthic ‘zoophytes’ with pelagic ciliated larvae allowed trophic continuity from phagocytic protozoa to gut-endowed animals. Choanoflagellate protozoa produced sponges. Converting sponge flask cells mediating larval settling to synaptically controlled nematocysts arguably made Cnidaria. I replace Haeckel's gastraea theory by a sponge/coelenterate/bilaterian pathway: Placozoa, hydrozoan diploblasty and ctenophores were secondary; stem anthozoan developmental mutations arguably independently generated coelomate bilateria and ctenophores. I emphasize animal origin's conceptual aspects (selective, developmental) related to feeding modes, cell structure, phylogeny of related protozoa, sequence evidence, ecology and palaeontology. Epithelia and connective tissue could evolve only by compensating for dramatically lower feeding efficiency that differentiation into non-choanocytes entails. Consequentially, larger bodies enabled filtering more water for bacterial food and harbouring photosynthetic bacteria, together adding more food than cell differentiation sacrificed. A hypothetical presponge of sessile triploblastic sheets (connective tissue sandwiched between two choanocyte epithelia) evolved oogamy through selection for larger dispersive ciliated larvae to accelerate benthic trophic competence and overgrowing protozoan competitors. Extinct Vendozoa might be elaborations of this organismal grade with choanocyte-bearing epithelia, before poriferan water channels and cnidarian gut/nematocysts/synapses evolved. This article is part of the themed issue ‘Evo-devo in the genomics era, and the origins of morphological diversity’.

scholarly journals Major evolutionary transitions and innovations: the tympanic middle ear

2017 ◽  
Vol 372 (1713) ◽  
pp. 20150483 ◽  
Author(s):  
Abigail S. Tucker
Keyword(s):  
Middle Ear ◽  
Morphological Diversity ◽  
The Novel ◽  
Evolutionary Transitions ◽  
Jaw Joint ◽  
Evolution Of Mammals ◽  
Key Steps ◽  
Evo Devo ◽  
Relationship Of ◽  
The Relationship

One of the most amazing transitions and innovations during the evolution of mammals was the formation of a novel jaw joint and the incorporation of the original jaw joint into the middle ear to create the unique mammalian three bone/ossicle ear. In this review, we look at the key steps that led to this change and other unusual features of the middle ear and how developmental biology has been providing an understanding of the mechanisms involved. This starts with an overview of the tympanic (air-filled) middle ear, and how the ear drum (tympanic membrane) and the cavity itself form during development in amniotes. This is followed by an investigation of how the ear is connected to the pharynx and the relationship of the ear to the bony bulla in which it sits. Finally, the novel mammalian jaw joint and versatile dentary bone will be discussed with respect to evolution of the mammalian middle ear. This article is part of the themed issue ‘Evo-devo in the genomics era, and the origins of morphological diversity’.

scholarly journals Evo-devo and accounting for Darwin's endless forms

2011 ◽  
Vol 366 (1574) ◽  
pp. 2069-2075 ◽  
Author(s):  
Paul M. Brakefield
Keyword(s):  
Natural Selection ◽  
Common Ancestry ◽  
Developmental Constraints ◽  
Evolutionary Diversification ◽  
New Genes ◽  
The Earth ◽  
Regulatory Machinery ◽  
Evo Devo ◽  
Opening Up ◽  
Trait Space

Evo-devo has led to dramatic advances in our understanding of how the processes of development can contribute to explaining patterns of evolutionary diversification that underlie the endless forms of animal life on the Earth. This is increasingly the case not only for the origins of evolutionary novelties that permit new functions and open up new adaptive zones, but also for the processes of evolutionary tinkering that occur within the subsequent radiations of related species. Evo-devo has time and again yielded spectacular examples of Darwin's notions of common ancestry and of descent with modification. It has also shown that the evolution of endless forms is more about the evolution of the regulatory machinery of ancient genes than the origin and elaboration of new genes. Evolvability, especially with respect to the capacity of a developmental system to evolve and to generate the variation in form for natural selection to screen, has become a pivotal focus of evo-devo. As a consequence, a balancing of the concept of endless forms in morphospace with a greater awareness of the potential for developmental constraints and bias is becoming more general. The prospect of parallel horizons opening up for the evolution of behaviour is exciting; in particular, does Sean Carroll's phrase referring to old genes learning new tricks in the evolution of endless forms apply equally as well to patterns of diversity and disparity in behavioural trait-space?

scholarly journals Trait decoupling promotes evolutionary diversification of the trophic and acoustic system of damselfishes

2014 ◽  
Vol 281 (1789) ◽  
pp. 20141047 ◽  
Author(s):  
Bruno Frédérich ◽  
Damien Olivier ◽  
Glenn Litsios ◽  
Michael E. Alfaro ◽  
Eric Parmentier
Keyword(s):  
Sound Production ◽  
Evolutionary Rate ◽  
Morphological Evolution ◽  
Ecological Diversification ◽  
Evolutionary Diversification ◽  
The Family ◽  
Acoustic Diversity ◽  
Empirical Tests ◽  
Evolutionary Consequences ◽  
Integrated Structures

Trait decoupling, wherein evolutionary release of constraints permits specialization of formerly integrated structures, represents a major conceptual framework for interpreting patterns of organismal diversity. However, few empirical tests of this hypothesis exist. A central prediction, that the tempo of morphological evolution and ecological diversification should increase following decoupling events, remains inadequately tested. In damselfishes (Pomacentridae), a ceratomandibular ligament links the hyoid bar and lower jaws, coupling two main morphofunctional units directly involved in both feeding and sound production. Here, we test the decoupling hypothesis by examining the evolutionary consequences of the loss of the ceratomandibular ligament in multiple damselfish lineages. As predicted, we find that rates of morphological evolution of trophic structures increased following the loss of the ligament. However, this increase in evolutionary rate is not associated with an increase in trophic breadth, but rather with morphofunctional specialization for the capture of zooplanktonic prey. Lineages lacking the ceratomandibular ligament also shows different acoustic signals (i.e. higher variation of pulse periods) from others, resulting in an increase of the acoustic diversity across the family. Our results support the idea that trait decoupling can increase morphological and behavioural diversity through increased specialization rather than the generation of novel ecotypes.

scholarly journals Phylogenetic evidence for the modular evolution of metazoan signalling pathways

2017 ◽  
Vol 372 (1713) ◽  
pp. 20150477 ◽  
Author(s):  
Leslie S. Babonis ◽  
Mark Q. Martindale
Keyword(s):  
Cell Signalling ◽  
Large Body ◽  
Morphological Diversity ◽  
Signalling Pathway ◽  
Signalling Pathways ◽  
Special Focus ◽  
Tissue Interactions ◽  
Modular Evolution ◽  
Membrane Bound ◽  
Evo Devo

Communication among cells was paramount to the evolutionary increase in cell type diversity and, ultimately, the origin of large body size. Across the diversity of Metazoa, there are only few conserved cell signalling pathways known to orchestrate the complex cell and tissue interactions regulating development; thus, modification to these few pathways has been responsible for generating diversity during the evolution of animals. Here, we summarize evidence for the origin and putative function of the intracellular, membrane-bound and secreted components of seven metazoan cell signalling pathways with a special focus on early branching metazoans (ctenophores, poriferans, placozoans and cnidarians) and basal unikonts (amoebozoans, fungi, filastereans and choanoflagellates). We highlight the modular incorporation of intra- and extracellular components in each signalling pathway and suggest that increases in the complexity of the extracellular matrix may have further promoted the modulation of cell signalling during metazoan evolution. Most importantly, this updated view of metazoan signalling pathways highlights the need for explicit study of canonical signalling pathway components in taxa that do not operate a complete signalling pathway. Studies like these are critical for developing a deeper understanding of the evolution of cell signalling. This article is part of the themed issue ‘Evo-devo in the genomics era, and the origins of morphological diversity’.

scholarly journals Floristic diversity of Umari Dham sacred grove in Jaipur, Rajasthan, India

2021 ◽  
Vol 11 (4) ◽  
pp. 109-121
Author(s):  
Yogita Solanki ◽  
Amit Kotiya
Keyword(s):  
Plant Species ◽  
Field Investigation ◽  
Flowering Plant ◽  
Sacred Grove ◽  
Floristic Diversity ◽  
Wildlife Sanctuary ◽  
Group Iii ◽  
Floral Diversity ◽  
Flowering Plant Species ◽  
The City

The Umari Dham is a sacred grove situated at the Jamwa Ramgarh Wildlife Sanctuary, Jaipur District of Rajasthan, India. It’s a beautiful arbour near the city of Jaipur. Umari Dham sacred grove has a temple, which has been visited by worshippers for approximately 450 years. During present field investigation, attempts were made to categorize the floral diversity of this sacred grove, and around 215 flowering plant species belonging to 159 genera under 52 families have been recorded according to Angiosperm Phylogeny Group III (APG III) classification. This grove serves as a vital pool for preservation of threatened, endemic and medicinal plant species.

scholarly journals Dramatic evolution of body length due to post-embryonic changes in cell size in a newly discovered close relative of C. elegans

2017 ◽  
Author(s):  
Gavin C. Woodruff ◽  
Patrick C. Phillips
Keyword(s):  
Body Size ◽  
Cell Size ◽  
Germ Line ◽  
Large Body ◽  
Developmental Genetics ◽  
Close Relative ◽  
Size Difference ◽  
C Elegans ◽  
Evolutionary Diversification ◽  
Ideal System

AbstractUnderstanding morphological diversity—and morphological constrainto—has been a central question in evolutionary biology since its inception. Nematodes of the genus Caenorhabditis, which contains the well-studied model system C. elegans, display remarkable morphological consistency in the face of extensive genetic divergence. Here, we provide a description of the broad developmental patterns of a recently discovered species, C. sp. 34, which was isolated from fresh figs in Okinawa and which is among the closest known relatives of C. elegans. C. sp. 34 displays an extremely large body size and can grow to be nearly twice as long as C. elegans and all other known members of the genus. Observations of the timing of developmental milestones reveal that C. sp. 34 develops about twice as slowly as C. elegans. Measurements of embryo and larval size show that the size difference between C. sp. 34 and C. elegans is largely due to post-embryonic events, particularly during the transition from larval to adult stages. This difference in size is not attributable to differences in germ line chromosome number or the number of somatic cells. The overall difference in body size is therefore largely attributable to changes in cell size via increased cytoplasmic volume. Because of its close relationship to C. elegans, the distinctness of C. sp. 34 provides an ideal system for the detailed analysis of evolutionary diversification. The context of over forty years of C. elegans developmental genetics also reveals clues into how natural selection and developmental constraint act jointly to promote patterns of morphological stasis and divergence in this group.

scholarly journals Cavefish and the basis for eye loss

2017 ◽  
Vol 372 (1713) ◽  
pp. 20150487 ◽  
Author(s):  
Jaya Krishnan ◽  
Nicolas Rohner
Keyword(s):  
Embryonic Development ◽  
Convergent Evolution ◽  
Current Knowledge ◽  
Morphological Diversity ◽  
Astyanax Mexicanus ◽  
Genomic Resources ◽  
Evolutionary Forces ◽  
Different Populations ◽  
Entire World ◽  
Evo Devo

Animals have colonized the entire world from rather moderate to the harshest environments, some of these so extreme that only few animals are able to survive. Cave environments present such a challenge and obligate cave animals have adapted to perpetual darkness by evolving a multitude of traits. The most common and most studied cave characteristics are the regression of eyes and the overall reduction in pigmentation. Studying these traits can provide important insights into how evolutionary forces drive convergent and regressive adaptation. The blind Mexican cavefish ( Astyanax mexicanus ) has emerged as a useful model to study cave evolution owing to the availability of genetic and genomic resources, and the amenability of embryonic development as the different populations remain fertile with each other. In this review, we give an overview of our current knowledge underlying the process of regressive and convergent evolution using eye degeneration in cavefish as an example. This article is part of the themed issue ‘Evo-devo in the genomics era, and the origins of morphological diversity’.

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