Distinct suites of pre‐ and post‐adaptations indicate independent evolutionary pathways of snapping claws in the shrimp family Alpheidae (Decapoda: Caridea)

Evolution ◽  
2021 ◽  
Author(s):  
Lai Him Chow ◽  
Sammy De Grave ◽  
Arthur Anker ◽  
Karina Ka Yan Poon ◽  
Ka Yan Ma ◽  
...  
Keyword(s):  
Evolutionary Pathways

scholarly journals Directed Evolution of Ionizing Radiation Resistance in Escherichia coli

2009 ◽  
Vol 191 (16) ◽  
pp. 5240-5252 ◽  
Author(s):  
Dennis R. Harris ◽  
Steve V. Pollock ◽  
Elizabeth A. Wood ◽  
Reece J. Goiffon ◽  
Audrey J. Klingele ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ionizing Radiation ◽  
Directed Evolution ◽  
Radiation Resistance ◽  
Bacterial Species ◽  
Repair System ◽  
Multiple Alleles ◽  
Evolutionary Pathways ◽  
K 12 ◽  
Ionizing Radiation Resistance

ABSTRACT We have generated extreme ionizing radiation resistance in a relatively sensitive bacterial species, Escherichia coli, by directed evolution. Four populations of Escherichia coli K-12 were derived independently from strain MG1655, with each specifically adapted to survive exposure to high doses of ionizing radiation. D37 values for strains isolated from two of the populations approached that exhibited by Deinococcus radiodurans. Complete genomic sequencing was carried out on nine purified strains derived from these populations. Clear mutational patterns were observed that both pointed to key underlying mechanisms and guided further characterization of the strains. In these evolved populations, passive genomic protection is not in evidence. Instead, enhanced recombinational DNA repair makes a prominent but probably not exclusive contribution to genome reconstitution. Multiple genes, multiple alleles of some genes, multiple mechanisms, and multiple evolutionary pathways all play a role in the evolutionary acquisition of extreme radiation resistance. Several mutations in the recA gene and a deletion of the e14 prophage both demonstrably contribute to and partially explain the new phenotype. Mutations in additional components of the bacterial recombinational repair system and the replication restart primosome are also prominent, as are mutations in genes involved in cell division, protein turnover, and glutamate transport. At least some evolutionary pathways to extreme radiation resistance are constrained by the temporally ordered appearance of specific alleles.

scholarly journals Evolutionary pathways to self-fertilization in a tristylous plant species

2009 ◽  
Vol 183 (3) ◽  
pp. 546-556 ◽  
Author(s):  
Spencer C. H. Barrett ◽  
Rob W. Ness ◽  
Mario Vallejo-Marín
Keyword(s):  
Plant Species ◽  
Self Fertilization ◽  
Evolutionary Pathways

scholarly journals Survivable hypothermia or torpor in a wild-living rat: rare insights broaden our understanding of endothermic physiology

2021 ◽  
Author(s):  
Julia Nowack ◽  
Christopher Turbill
Keyword(s):  
Body Temperature ◽  
Data Sets ◽  
Valuable Insight ◽  
Limited Capacity ◽  
Probability Of Survival ◽  
Reduced Body ◽  
Rattus Fuscipes ◽  
Evolutionary Pathways ◽  
Term Data

AbstractMaintaining a high and stable body temperature as observed in endothermic mammals and birds is energetically costly. Thus, it is not surprising that we discover more and more heterothermic species that can reduce their energetic needs during energetic bottlenecks through the use of torpor. However, not all heterothermic animals use torpor on a regular basis. Torpor may also be important to an individual’s probability of survival, and hence fitness, when used infrequently. We here report the observation of a single, ~ 5.5 h long hypothermic bout with a decrease in body temperature by 12 °C in the native Australian bush rat (Rattus fuscipes). Our data suggest that bush rats are able to rewarm from a body temperature of 24 °C, albeit with a rewarming rate lower than that expected on the basis of their body mass. Heterothermy, i.e. the ability to withstand and overcome periods of reduced body temperature, is assumed to be an evolutionarily ancestral (plesiomorphic) trait. We thus argue that such rare hypothermic events in species that otherwise appear to be strictly homeothermic could be heterothermic rudiments, i.e. a less derived form of torpor with limited capacity for rewarming. Importantly, observations of rare and extreme thermoregulatory responses by wild animals are more likely to be discovered with long-term data sets and may not only provide valuable insight about the physiological capability of a population, but can also help us to understand the constraints and evolutionary pathways of different phenologies.

scholarly journals An integrative method for testing form–function linkages and reconstructed evolutionary pathways of masticatory specialization

2015 ◽  
Vol 12 (107) ◽  
pp. 20150184 ◽  
Author(s):  
Z. Jack Tseng ◽  
John J. Flynn
Keyword(s):  
Mechanical Properties ◽  
Morphological Evolution ◽  
Integrative Approach ◽  
Deep Time ◽  
Integrate Form ◽  
Functional Changes ◽  
Form And Function ◽  
Form Function ◽  
Evolutionary Pathways ◽  
And Function

Morphology serves as a ubiquitous proxy in macroevolutionary studies to identify potential adaptive processes and patterns. Inferences of functional significance of phenotypes or their evolution are overwhelmingly based on data from living taxa. Yet, correspondence between form and function has been tested in only a few model species, and those linkages are highly complex. The lack of explicit methodologies to integrate form and function analyses within a deep-time and phylogenetic context weakens inferences of adaptive morphological evolution, by invoking but not testing form–function linkages. Here, we provide a novel approach to test mechanical properties at reconstructed ancestral nodes/taxa and the strength and direction of evolutionary pathways in feeding biomechanics, in a case study of carnivorous mammals. Using biomechanical profile comparisons that provide functional signals for the separation of feeding morphologies, we demonstrate, using experimental optimization criteria on estimation of strength and direction of functional changes on a phylogeny, that convergence in mechanical properties and degree of evolutionary optimization can be decoupled. This integrative approach is broadly applicable to other clades, by using quantitative data and model-based tests to evaluate interpretations of function from morphology and functional explanations for observed macroevolutionary pathways.

scholarly journals Challenges faced by current Galactic planetary nebula surveys

2016 ◽  
Vol 12 (S323) ◽  
pp. 11-19
Author(s):  
David J. Frew
Keyword(s):  
Planetary Nebula ◽  
Time Interval ◽  
Important Goal ◽  
Satellite Mission ◽  
Galactic Population ◽  
Multi Wavelength ◽  
Evolutionary Pathways ◽  
Optical Surveys ◽  
Central Stars ◽  
Galactic Planetary Nebula

AbstractDetermining the demographics of the Galactic planetary nebula (PN) population is an important goal to further our understanding of this intriguing phase of stellar evolution. The Galactic population has more than doubled in number over the last 15 years, particularly from narrowband Hα surveys along the plane. In this review I will summarise these results, with emphasis on the time interval since the last IAU Symposium. These primarily optical surveys are not without their limitations and new surveys for PNe in the infrared similarly face a number of challenges. I will discuss the need for multi-wavelength approaches to discovery and analysis. The desire to have accurate volume-limited samples of Galactic PNe at our disposal is emphasised, which will be impacted with new data from the Gaia satellite mission. We need robust surveys of PNe and their central stars, especially volume-limited surveys, in order to clarify and quantify their evolutionary pathways.

scholarly journals Colistin resistance in Parisian inpatient faecal Escherichia coli as the result of two distinct evolutionary pathways

2019 ◽  
Vol 74 (6) ◽  
pp. 1521-1530 ◽  
Author(s):  
Anne Sophie Bourrel ◽  
Laurent Poirel ◽  
Guilhem Royer ◽  
Mélanie Darty ◽  
Xavier Vuillemin ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Colistin Resistance ◽  
Evolutionary Pathways

scholarly journals The evolution of sexual dimorphism in parasitic cuckoos: sexual selection or coevolution?

2007 ◽  
Vol 274 (1617) ◽  
pp. 1553-1560 ◽  
Author(s):  
O Krüger ◽  
N.B Davies ◽  
M.D Sorenson
Keyword(s):  
Sexual Selection ◽  
Sexual Dimorphism ◽  
Parental Care ◽  
Brood Parasitism ◽  
Selection Pressure ◽  
Life Histories ◽  
Exceptional Case ◽  
Evolutionary Pathways ◽  
Common Situation

Sexual dimorphism is ubiquitous in animals and can result from selection pressure on one or both sexes. Sexual selection has become the predominant explanation for the evolution of sexual dimorphism, with strong selection on size-related mating success in males being the most common situation. The cuckoos (family Cuculidae) provide an exceptional case in which both sexes of many species are freed from the burden of parental care but where coevolution between parasitic cuckoos and their hosts also results in intense selection. Here, we show that size and plumage differences between the sexes in parasitic cuckoos are more likely the result of coevolution than sexual selection. While both sexes changed in size as brood parasitism evolved, we find no evidence for selection on males to become larger. Rather, our analysis indicates stronger selection on parasitic females to become smaller, resulting in a shift from dimorphism with larger females in cuckoos with parental care to dimorphism with larger males in parasitic species. In addition, the evolution of brood parasitism was associated with more cryptic plumage in both sexes, but especially in females, a result that contrasts with the strong plumage dimorphism seen in some other parasitic birds. Examination of the three independent origins of brood parasitism suggests that different parasitic cuckoo lineages followed divergent evolutionary pathways to successful brood parasitism. These results argue for the powerful role of parasite–host coevolution in shaping cuckoo life histories in general and sexual dimorphism in particular.

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