scholarly journals The importance of offshore origination revealed through ophiuroid phylogenomics

2017 ◽  
Vol 284 (1858) ◽  
pp. 20170160 ◽  
Author(s):  
Guadalupe Bribiesca-Contreras ◽  
Heroen Verbruggen ◽  
Andrew F. Hugall ◽  
Timothy D. O'Hara
Keyword(s):  
Deep Sea ◽  
Marine Invertebrates ◽  
Range Shift ◽  
Evolutionary Adaptation ◽  
Evolutionary Processes ◽  
Opposite Pattern ◽  
Bathymetric Range ◽  
Evolutionary Pattern ◽  
Transitional State ◽  
Over Time

Our knowledge of macro-evolutionary processes in the deep sea is poor, leading to much speculation about whether the deep sea is a source or sink of evolutionary adaptation. Here, we use a phylogenetic approach, on large molecular (688 species, 275 kbp) and distributional datasets (104 513 records) across an entire class of marine invertebrates (Ophiuroidea), to infer rates of bathymetric range shift over time between shallow and deep water biomes. Biome conservation is evident through the phylogeny, with the majority of species in most clades distributed within the same bathome. Despite this, bathymetric shifts have occurred. We inferred from ancestral reconstructions that eurybathic or intermediate distributions across both biomes were a transitional state and direct changes between shallow and deep sea did not occur. The macro-evolutionary pattern of bathome shift appeared to reflect micro-evolutionary processes of bathymetric speciation. Results suggest that most of the oldest clades have a deep-sea origin, but multiple colonization events indicate that the evolution of this group conforms neither to a simple onshore–offshore hypothesis, nor the opposite pattern. Both shallow and deep bathomes have played an important role in generating the current diversity of this major benthic class.

scholarly journals Dispersal and Differentiation of Deep-Sea Mussels of the GenusBathymodiolus(Mytilidae, Bathymodiolinae)

2009 ◽  
Vol 2009 ◽  
pp. 1-15 ◽  
Author(s):  
Akiko Kyuno ◽  
Mifue Shintaku ◽  
Yuko Fujita ◽  
Hiroto Matsumoto ◽  
Motoo Utsumi ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Shallow Water ◽  
Deep Sea ◽  
Dispersal Ability ◽  
Evolutionary Transition ◽  
Significant Genetic Differentiation ◽  
Evolutionary Processes ◽  
High Dispersal ◽  
High Gene

We sequenced the mitochondrial ND4 gene to elucidate the evolutionary processes ofBathymodiolusmussels and mytilid relatives. Mussels of the subfamily Bathymodiolinae from vents and seeps belonged to 3 groups and mytilid relatives from sunken wood and whale carcasses assumed the outgroup positions to bathymodioline mussels. Shallow water mytilid mussels were positioned more distantly relative to the vent/seep mussels, indicating an evolutionary transition from shallow to deep sea via sunken wood and whale carcasses.Bathymodiolus platifronsis distributed in the seeps and vents, which are approximately 1500 km away. There was no significant genetic differentiation between the populations. There existed high gene flow betweenB. septemdierumandB. breviorand low but not negligible gene flow betweenB. marisindicusandB. septemdierumorB. brevior, although their habitats are 5000–10 000 km away. These indicate a high adaptability to the abyssal environments and a high dispersal ability ofBathymodiolusmussels.

Pressure and Temperature Adaptation of Cytosolic Malate Dehydrogenases of Shallowand Deep-Living Marine Invertebrates: Evidence for High Body Temperatures in Hydrothermal Vent Animals

1991 ◽  
Vol 159 (1) ◽  
pp. 473-487 ◽  
Author(s):  
ELIZABETH DAHLHOFF ◽  
GEORGE N. SOMERO
Keyword(s):  
Deep Sea ◽  
Hydrothermal Vents ◽  
Elevated Temperatures ◽  
Marine Invertebrates ◽  
Distribution Patterns ◽  
Pressure Effects ◽  
Temperature Adaptation ◽  
Body Temperatures ◽  
Elevated Pressures

Effects of temperature and hydrostatic pressure were measured on cytosolic malate dehydrogenases (cMDHs) from muscle tissue of a variety of shallow- and deep-living benthic marine invertebrates, including seven species endemic to the deep-sea hydrothermal vents. The apparent Michaelis-Menten constant (Km) of coenzyme (nicotinamide adenine dinucleotide, NADH), used to index temperature and pressure effects, was conserved within a narrow range (approximately 15–25 μmoll−1) at physiological temperatures and pressures for all species. However, at elevated pressures, the Km of NADH rose sharply for cMDHs of shallow species (depths of occurrence >Approximately 500 m), but not for the cMDHs of deep-sea species. Cytosolic MDHs of invertebrates from the deep-sea hydrothermal vents generally were not perturbed by elevated temperatures (15–25°C) at in situ pressures, but cMDHs of cold-adapted deep-sea species were. At a single measurement temperature, the Km of NADH for cMDHs from invertebrates from habitats with well-characterized temperatures was inversely related to maximal sustained body temperature. This correlation was used to predict the maximal sustained body temperatures of vent invertebrates for which maximal habitat and body temperatures are difficult to estimate. Species occurring on the ‘smoker chimneys’, which emit waters with temperatures up to 380°C, are predicted to have sustained body temperatures that are approximately 20–25°C higher than vent species living in cooler vent microhabitats. We conclude that, just as adaptation of enzymes to elevated pressures is important in establishing species’ depth distribution patterns, adaptation of pressure-adapted enzymes to temperature is critical in enabling certain vent species to exploit warm-water microhabitats in the vent environment.

Emergence of diversity and stereochemical outcomes in the biosynthetic pathways of cyclobutane-centered marine alkaloid dimers

2016 ◽  
Vol 33 (7) ◽  
pp. 820-842 ◽  
Author(s):  
Mehdi A. Beniddir ◽  
Laurent Evanno ◽  
Delphine Joseph ◽  
Adam Skiredj ◽  
Erwan Poupon
Keyword(s):  
Deep Sea ◽  
Marine Invertebrates ◽  
Biosynthetic Pathways ◽  
Marine Alkaloid

A deep-sea dive into the ecology and chemistry of surprising cyclobutanes from marine invertebrates.

Melanism and ontogeny: a case study in lizards of the Liolaemus fitzingerii group (Squamata: Liolaemini)

2016 ◽  
Vol 94 (3) ◽  
pp. 199-206 ◽  
Author(s):  
P.C. Escudero ◽  
I. Minoli ◽  
M.A. González Marín ◽  
M. Morando ◽  
L.J. Avila
Keyword(s):  
New Species ◽  
Body Size ◽  
Comparative Studies ◽  
Species Group ◽  
Evolutionary Adaptation ◽  
Body Measurements ◽  
Adaptation Studies ◽  
Present Evidence ◽  
Over Time

Color polymorphisms in general and melanism in particular have been the focus of many evolutionary adaptation studies. In lizards of the genus Liolaemus Wiegmann, 1834, patterns of melanism have been poorly studied, although they have been used as diagnostic characters for identifying and describing new species. We investigated the relationships between melanism, body size, sex, and time in a population of Rawson Lizard (Liolaemus xanthoviridis Cei and Scolaro, 1980) with extensive ventral melanism. The study took place in Bahía Isla Escondida, Chubut (Argentina), during three summer seasons (2012 to 2014). We tagged each individual, recorded body measurements and sex, and took ventral photographs to estimate the proportion of melanism. Our results showed that ventral melanism increased over time as each individual increased its snout–vent length (SVL). Body size explained 44% of the variation in melanism and males were more melanistic than females. Previous comparative studies of lizards in this species group showed no relationship between melanism and different taxonomic units or with thermal functionality. Here, we present evidence suggesting that melanism might be a character with an ontogenetic origin that is strongly associated with sex and body size. This pattern could be shared among species of this group of lizards, and even more importantly, it may be related to variable selection forces occurring throughout ontogeny.

scholarly journals Thriving of hyperthermophilic microbial communities from a deep-sea sulfidic hydrothermal chimney under electrolithoautotrophic conditions with nitrate as electron acceptor

2021 ◽  
Author(s):  
G. Pillot ◽  
S. Davidson ◽  
L. Shintu ◽  
L. Tanet ◽  
Y. Combet-Blanc ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Electron Acceptor ◽  
Deep Sea ◽  
Electrical Current ◽  
Energy Sources ◽  
Phylogenetic Groups ◽  
Organic Products ◽  
Electrical Consumption ◽  
Over Time

AbstractRecent studies have shown the presence of an abiotic electrical current across the walls of deep-sea hydrothermal chimneys, allowing the growth of electroautotrophic microbial communities. To understand the role of the different phylogenetic groups and metabolisms involved, this study focused on an electrotrophic enrichment, with nitrate as electron acceptor. The biofilm density, the community composition, the organic products released, and the electrical consumption were monitored by FISH confocal microscopy, qPCR, Metabarcoding, MNR and potentiostat measurements. A statistic analysis by PCA showed the correlation between the different parameters in 3 distinct temporal phases. The Archaeoglobales have been shown to play a key role in the development of the community, as first colonizers and producing pyruvate, therefor used as organic source for heterotrophs. Some Thermococcales showed the ability to perform electrofermentation of this pyruvate into acetate and H2. Finally, through subcultures of the community, we showed the development of a larger biodiversity over time. This observed phenomenon could explain the biodiversity development in hydrothermal context where energy sources are transient and unstable.

scholarly journals Dynamics and variability in the pleiotropic effects of adaptation in laboratory budding yeast populations

2021 ◽  
Author(s):  
Christopher W Bakerlee ◽  
Angela M Phillips ◽  
Alex N Nguyen Ba ◽  
Michael M Desai
Keyword(s):  
Budding Yeast ◽  
Pleiotropic Effects ◽  
Evolutionary Adaptation ◽  
Complex Environments ◽  
Space And Time ◽  
Constant Environment ◽  
Fluctuating Environments ◽  
Evolutionary Trajectories ◽  
Multiple Environments ◽  
Over Time

Evolutionary adaptation to a constant environment is driven by the accumulation of mutations which can have a range of unrealized pleiotropic effects in other environments. These pleiotropic consequences of adaptation can influence the emergence of specialists or generalists, and are critical for evolution in temporally or spatially fluctuating environments. While many experiments have examined the pleiotropic effects of adaptation at a snapshot in time, very few have observed the dynamics by which these effects emerge and evolve. Here, we propagated hundreds of diploid and haploid laboratory budding yeast populations in each of three environments, and then assayed their fitness in multiple environments over 1000 generations of evolution. We find that replicate populations evolved in the same condition share common patterns of pleiotropic effects across other environments, which emerge within the first several hundred generations of evolution. However, we also find dynamic and environment-specific variability within these trends: variability in pleiotropic effects tends to increase over time, with the extent of variability depending on the evolution environment. These results suggest shifting and overlapping contributions of chance and contingency to the pleiotropic effects of adaptation, which could influence evolutionary trajectories in complex environments that fluctuate across space and time.

scholarly journals The polysemy of the words that children learn over time

2018 ◽  
Vol 19 (3) ◽  
pp. 389-426 ◽  
Author(s):  
Bernardino Casas ◽  
Neus Català ◽  
Ramon Ferrer-i-Cancho ◽  
Antoni Hernández-Fernández ◽  
Jaume Baixeries
Keyword(s):  
Side Effect ◽  
Vocabulary Acquisition ◽  
Vocabulary Learning ◽  
Fast Growth ◽  
Syntactic Category ◽  
Evolutionary Pattern ◽  
Part Of Speech ◽  
Two Phases ◽  
Polysemous Words ◽  
Over Time

Abstract Here we study polysemy as a potential learning bias in vocabulary learning in children. Words of low polysemy could be preferred as they reduce the disambiguation effort for the listener. However, such preference could be a side-effect of another bias: the preference of children for nouns in combination with the lower polysemy of nouns with respect to other part-of-speech categories. Our results show that mean polysemy in children increases over time in two phases, i.e. a fast growth till the 31st month followed by a slower tendency towards adult speech. In contrast, this evolution is not found in adults interacting with children. This suggests that children have a preference for non-polysemous words in their early stages of vocabulary acquisition. Interestingly, the evolutionary pattern described above weakens when controlling for syntactic category (noun, verb, adjective or adverb) but it does not disappear completely, suggesting that it could result from a combination of a standalone bias for low polysemy and a preference for nouns.

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