scholarly journals Somatic musculature of Tardigrada: phylogenetic signal and metameric patterns

2013 ◽  
Vol 169 (3) ◽  
pp. 580-603 ◽  
Author(s):  
Trevor Marchioro ◽  
Lorena Rebecchi ◽  
Michele Cesari ◽  
Jesper Guldberg Hansen ◽  
Giulia Viotti ◽  
...  
Keyword(s):  
Phylogenetic Signal ◽  
Somatic Musculature

Disentangling the role of shared ancestry and the environment on leaf stable isotopes

2019 ◽  
Author(s):  
Marko J. Spasojevic ◽  
Sören Weber1
Keyword(s):  
Stable Isotopes ◽  
Environmental Conditions ◽  
Evolutionary History ◽  
Environmental Control ◽  
Phylogenetic Signal ◽  
Individual Species ◽  
Habitat Types ◽  
Δ13c And Δ15n ◽  
Environmental Controls ◽  
Shared Ancestry

Stable carbon (C) and nitrogen (N) isotopes in plants are important indicators of plant water use efficiency and N acquisition strategies. While often regarded as being under environmental control, there is growing evidence that evolutionary history may also shape variation in stable isotope ratios (δ13C and δ15N) among plant species. Here we examined patterns of foliar δ13C and δ15N in alpine tundra for 59 species in 20 plant families. To assess the importance of environmental controls and evolutionary history, we examined if average δ13C and δ15N predictably differed among habitat types, if individual species exhibited intraspecific trait variation (ITV) in δ13C and δ15N, and if there were a significant phylogenetic signal in δ13C and δ15N. We found that variation among habitat types in both δ13C and δ15N mirrored well-known patterns of water and nitrogen limitation. Conversely, we also found that 40% of species exhibited no ITV in δ13C and 35% of species exhibited no ITV in δ15N, suggesting that some species are under stronger evolutionary control. However, we only found a modest signal of phylogenetic conservatism in δ13C and no phylogenetic signal in δ15N suggesting that shared ancestry is a weaker driver of tundra wide variation in stable isotopes. Together, our results suggest that both evolutionary history and local environmental conditions play a role in determining variation in δ13C and δ15N and that considering both factors can help with interpreting isotope patterns in nature and with predicting which species may be able to respond to rapidly changing environmental conditions.

scholarly journals Phylogenetic paleoecology: macroecology within an evolutionary framework

Paleobiology ◽  
2021 ◽  
Vol 47 (2) ◽  
pp. 171-177
Author(s):  
James C. Lamsdell ◽  
Curtis R. Congreve
Keyword(s):  
Species Diversity ◽  
Spatial Variation ◽  
Geographic Distribution ◽  
Evolutionary Biology ◽  
Phylogenetic Signal ◽  
Evolutionary Rates ◽  
The Other ◽  
Ecological Data ◽  
Temporal And Spatial Variation ◽  
Temporal And Spatial

The burgeoning field of phylogenetic paleoecology (Lamsdell et al. 2017) represents a synthesis of the related but differently focused fields of macroecology (Brown 1995) and macroevolution (Stanley 1975). Through a combination of the data and methods of both disciplines, phylogenetic paleoecology leverages phylogenetic theory and quantitative paleoecology to explain the temporal and spatial variation in species diversity, distribution, and disparity. Phylogenetic paleoecology is ideally situated to elucidate many fundamental issues in evolutionary biology, including the generation of new phenotypes and occupation of previously unexploited environments; the nature of relationships among character change, ecology, and evolutionary rates; determinants of the geographic distribution of species and clades; and the underlying phylogenetic signal of ecological selectivity in extinctions and radiations. This is because phylogenetic paleoecology explicitly recognizes and incorporates the quasi-independent nature of evolutionary and ecological data as expressed in the dual biological hierarchies (Eldredge and Salthe 1984; Congreve et al. 2018; Fig. 1), incorporating both as covarying factors rather than focusing on one and treating the other as error within the dataset.

scholarly journals The Alcohol Dehydrogenase Gene Is Nested in the outspread Locus of Drosophila melanogaster

Genetics ◽  
1996 ◽  
Vol 143 (2) ◽  
pp. 897-911 ◽  
Author(s):  
S McNabb ◽  
S Greig ◽  
T Davis
Keyword(s):  
Drosophila Melanogaster ◽  
Alcohol Dehydrogenase ◽  
Pcr Amplification ◽  
Transcription Unit ◽  
Adjacent Gene ◽  
Dehydrogenase Gene ◽  
Chromosomal Breakpoints ◽  
Splicing Patterns ◽  
Somatic Musculature

Abstract This report describes the structure and expression of the outspread (osp) gene of Drosophila melanogaster. Previous work showed that chromosomal breakpoints associated with mutations of the osp locus map to both sides of the alcohol dehydrogenase gene (Adh), suggesting that Adh and the adjacent gene Adh' are nested in osp. We extended a chromosomal walk and mapped additional osp mutations to define the maximum molecular limit of osp as 119 kb. We identified a 6-kb transcript that hybridizes to osp region DNA and is altered or absent in osp mutants. Accumulation of this RNA peaks during embryonic and pupal periods. The osp cDNAs comprise two distinct classes based on alternative splicing patterns. The 5′ end of the longest cDNA was extended by PCR amplification. When hybridized to the osp walk, the 5′ extension verifies that Adh and Adh' are nested in osp and shows that osp has a transcription unit of ≥74 kb. In situ hybridization shows that osp is expressed both maternally and zygotically. In the ovary, osp is transcribed in nurse cells and localized in the oocyte. In embryos, expression is most abundant in the developing visceral and somatic musculature.

Larval morphology predicts geographical dispersal range of Eastern Pacific eels

2019 ◽  
Vol 128 (1) ◽  
pp. 107-121 ◽  
Author(s):  
Katherine E Dale ◽  
M Timothy Tinker ◽  
Rita S Mehta
Keyword(s):  
Body Shape ◽  
Phylogenetic Signal ◽  
Morphological Diversity ◽  
Marine Species ◽  
Eastern Pacific ◽  
Geographical Range ◽  
Larval Body ◽  
Adult Morphology ◽  
Adult Habitat ◽  
Eggs And Larvae

Abstract The geographical range of many marine species is strongly influenced by the dispersal potential of propagules such as eggs and larvae. Here, we investigate morphological diversity and the effect of body shape on geographical range of leptocephali, the unique, laterally compressed larvae of eels (order Anguilliformes). We used phylogenetically informed analyses to examine the morphological variation of larvae for 17 Eastern Pacific eel species from three adult habitats. We also investigated whether morphological traits of leptocephali could predict larval latitudinal range, hypothesizing that body shape may influence passive dispersal via currents. We found that no two species shared the same multivariate growth trajectories, with the size and scaling of pectoral fin length and snout-to-anus length being particularly variable. Larvae with longer relative predorsal and snout-to-anus lengths at median sizes exhibited wider larval geographical ranges. Body aspect ratio and maximum body length at metamorphosis, two traits we hypothesized to be important for passive transport, were not significant predictors of maximal larval range. We discovered an increase in phylogenetic signal over larval development as eels approach metamorphosis, potentially due to similar selective pressures between related species (such as juvenile habitat or adult morphology). Lastly, we conclude that larval body shape is probably influenced by adult habitat and adult morphology.

scholarly journals Jaw biomechanics and the evolution of biting performance in theropod dinosaurs

2010 ◽  
Vol 277 (1698) ◽  
pp. 3327-3333 ◽  
Author(s):  
Manabu Sakamoto
Keyword(s):  
Function Space ◽  
Phylogenetic Signal ◽  
Space Distribution ◽  
Phylogenetic Structure ◽  
Unique Region ◽  
Theropod Dinosaurs ◽  
Polynomial Coefficients ◽  
Evolutionary Changes ◽  
Ancestral Function ◽  
Space Occupation

Despite the great diversity in theropod craniomandibular morphology, the presence and distribution of biting function types across Theropoda has rarely been assessed. A novel method of biomechanical profiling using mechanical advantage computed for each biting position along the entirety of the tooth row was applied to 41 extinct theropod taxa. Multivariate ordination on the polynomial coefficients of the profiles reveals the distribution of theropod biting performance in function space. In particular, coelophysoids are found to occupy a unique region of function space, while tetanurans have a wide but continuous function space distribution. Further, the underlying phylogenetic structure and evolution of biting performance were investigated using phylogenetic comparative methods. There is a strong phylogenetic signal in theropod biomechanical profiles, indicating that evolution of biting performance does not depart from Brownian motion evolution. Reconstructions of ancestral function space occupation conform to this pattern, but phylogenetically unexpected major shifts in function space occupation can be observed at the origins of some clades. However, uncertainties surround ancestor estimates in some of these internal nodes, so inferences on the nature of these evolutionary changes must be viewed with caution.

scholarly journals Patterns of genome size variation in snapping shrimp

Genome ◽  
2016 ◽  
Vol 59 (6) ◽  
pp. 393-402 ◽  
Author(s):  
Nicholas W. Jeffery ◽  
Kristin Hultgren ◽  
Solomon Tin Chi Chak ◽  
T. Ryan Gregory ◽  
Dustin R. Rubenstein
Keyword(s):  
Genome Size ◽  
Phylogenetic Signal ◽  
Size Variation ◽  
Diverse Group ◽  
Chromosome Size ◽  
Genome Size Variation ◽  
Large Genome ◽  
Large Genome Size ◽  
Single Genus ◽  
Geographic Regions

Although crustaceans vary extensively in genome size, little is known about how genome size may affect the ecology and evolution of species in this diverse group, in part due to the lack of large genome size datasets. Here we investigate interspecific, intraspecific, and intracolony variation in genome size in 39 species of Synalpheus shrimps, representing one of the largest genome size datasets for a single genus within crustaceans. We find that genome size ranges approximately 4-fold across Synalpheus with little phylogenetic signal, and is not related to body size. In a subset of these species, genome size is related to chromosome size, but not to chromosome number, suggesting that despite large genomes, these species are not polyploid. Interestingly, there appears to be 35% intraspecific genome size variation in Synalpheus idios among geographic regions, and up to 30% variation in Synalpheus duffyi genome size within the same colony.

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