scholarly journals Co‐option of stress mechanisms in the origin of evolutionary novelties

Evolution ◽  
2021 ◽  
Author(s):  
Alan Love ◽  
Günter P. Wagner
Keyword(s):  
Evolutionary Novelties

Evolutionary novelties

2014 ◽  
pp. 232-240
Author(s):  
Wallace Arthur
Keyword(s):  
Evolutionary Novelties

Micro- and macroevolution: Scale and hierarchy in evolutionary biology and paleobiology

Paleobiology ◽  
2000 ◽  
Vol 26 (S4) ◽  
pp. 15-52 ◽  
Author(s):  
David Jablonski
Keyword(s):  
Species Level ◽  
Raw Material ◽  
Developmental Genetics ◽  
Physical Factors ◽  
Morphologic Change ◽  
Mass Extinctions ◽  
Evolutionary Patterns ◽  
Extinction Rates ◽  
Organ Systems ◽  
Evolutionary Novelties

The study of evolution has increasingly incorporated considerations of history, scale, and hierarchy, in terms of both the origin of variation and the sorting of that variation. Although the macroevolutionary exploration of developmental genetics has just begun, considerable progress has been made in understanding the origin of evolutionary novelty in terms of the potential for coordinated morphological change and the potential for imposing uneven probabilities on different evolutionary directions. Global or whole-organism heterochrony, local heterochrony (affecting single structures, regions, or organ systems) and heterotopies (changes in the location of developmental events), and epigenetic mechanisms (which help to integrate the developing parts of an organism into a functional whole) together contribute to profound nonlinearities between genetic and morphologic change, by permitting the generation and accommodation of evolutionary novelties without pervasive, coordinated genetic changes; the limits of these developmental processes are poorly understood, however. The discordance across hierarchical levels in the production of evolutionary novelties through time, and among latitudes and environments, is an intriguing paleontological pattern whose explanation is controversial, in part because separating effects of genetics and ecology has proven difficult. At finer scales, species in the fossil record tend to be static over geologic time, although this stasis—to which there are gradualistic exceptions—generally appears to be underlain by extensive, nondirectional change rather than absolute invariance. Only a few studies have met the necessary protocols for the analysis of evolutionary tempo and mode at the species level, and so the distribution of evolutionary patterns among clades, environments, and modes of life remains poorly understood. Sorting among taxa is widely accepted in principle as an evolutionary mechanism, but detailed analyses are scarce; if geographic range or population density can be treated as traits above the organismic level, then the paleontological and mac̀roecological literature abounds in potential raw material for such analyses. Even if taxon sorting operates on traits that are not emergent at the species level, the differential speciation and extinction rates can shape large-scale evolutionary patterns in ways that are not simple extrapolations from short-term evolution at the organismal level. Changes in origination and extinction rates can evidently be mediated by interactions with other clades, although such interactions need to be studied in a geographically explicit fashion before the relative roles of biotic and physical factors can be assessed. Incumbency effects are important at many scales, with the most dramatic manifestation being the postextinction diversifications that follow the removal of incumbents. However, mass extinctions are evolutionarily important not only for the removal of dominant taxa, which can occur according to rules that differ from those operating during times of lower extinction intensity, but also for the dramatic diversifications that follow upon the removal or depletion of incumbents. Mass extinctions do not entirely reset the evolutionary clock, so survivors can exhibit unbroken evolutionary continuity, trends that suffer setbacks but then resume, or failure to participate in the recovery.

Phylogeny of Macronematinae (Trichoptera: Hydropsychidae) based on molecular and morphological analyses

2019 ◽  
Vol 151 (6) ◽  
pp. 696-716 ◽  
Author(s):  
Christine Jewel C. Uy ◽  
Ji Hyoun Kang ◽  
John C. Morse ◽  
Yeon Jae Bae
Keyword(s):  
Phylogenetic Relationships ◽  
Large Subunit ◽  
Phylogenetic Reconstruction ◽  
Morphological Characters ◽  
Nuclear Ribosomal Dna ◽  
Phylogenetic Study ◽  
Base Pairs ◽  
Morphological Findings ◽  
Close Relationship ◽  
Evolutionary Novelties

AbstractThe phylogenetic relationships among the members of Macronematinae (Trichoptera: Hydropsychidae) have long been debated and often revised. Our study based on a large subunit (28S) nuclear ribosomal DNA (D2 expansion fragment; 464 base pairs) of gene sequences found all genera to be monophyletic except for the genus Polymorphanisus Walker, which produced two clades in accordance with its species groups established using morphological characters. Phylogenetic reconstruction based on mitochondrial cytochrome oxidase I (658 base pairs) found the same monophyletic relationships, however, except for the genera Polymorphanisus and Macrostemum Kolenati. The placement of the genus Leptonema Guérin-Méneville as the basal clade in the subfamily was also ruled out, which is consistent with previous morphological findings. The monophyly of two previously recognised tribes (Macronematini and Polymorphanisini) was not supported. We also found that the genera Centromacronema Ulmer, Baliomorpha Neboiss, and Macronema Pictet are most closely related, having three head setal warts on the vertex of the head and unsegmented inferior appendages of male genitalia as their synapomorphies. Our study supported the hypothesis of close relationship of the genera Amphipsyche McLachlan and Protomacronema Ulmer with the morphological synapomorphies: absence of a forewing discoidal cell and the presence of elevated head carinae on the larvae. Some notable evolutionary novelties in the structure of adults in various lineages of this subfamily include reduction of maxillae and labium, reduction and loss of a discoidal cell and evolution of a c-sc crossvein in each forewing, fusion of segments in each male inferior appendage, and evolution of dark colour patterns in the forewings. Also, the head setal warts, which are unique organs in Trichoptera, evolved towards a decreasing number in the subfamily. This first molecular phylogenetic study, covering most genera in Macronematinae and including an interpretation of 12 key evolutionary novelties, provides an important basis for resolving long-standing questions regarding phylogenetic relationships and classification of genera and species and helps lay a stronger foundation for inference of testable hypotheses about functional traits for species of this common and widespread subfamily.

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