scholarly journals Allometric relationships in morphological traits associated with foraging, swimming ability, and predator defense reveal adaptations toward brackish and freshwater environments in the threespine stickleback

2020 ◽  
Vol 10 (23) ◽  
pp. 13412-13426
Author(s):  
Annette Taugbøl ◽  
Thomas P. Quinn ◽  
Kjartan Østbye ◽  
Leif Asbjørn Vøllestad
Keyword(s):  
Morphological Traits ◽  
Threespine Stickleback ◽  
Swimming Ability ◽  
Allometric Relationships ◽  
Predator Defense ◽  
Freshwater Environments

scholarly journals Should I stay or should I go? The Ectodysplasin locus is associated with behavioural differences in threespine stickleback

2009 ◽  
Vol 5 (6) ◽  
pp. 788-791 ◽  
Author(s):  
Rowan D. H. Barrett ◽  
Tim H. Vines ◽  
Jason S. Bystriansky ◽  
Patricia M. Schulte
Keyword(s):  
Positive Selection ◽  
Local Adaptation ◽  
Morphological Traits ◽  
Genetic Basis ◽  
Natural Populations ◽  
Threespine Stickleback ◽  
Adaptive Divergence ◽  
Freshwater Habitats ◽  
Repeated Evolution ◽  
Freshwater Environments

Adaptive divergence may be facilitated if morphological and behavioural traits associated with local adaptation share the same genetic basis. It is therefore important to determine whether genes underlying adaptive morphological traits are associated with variation in behaviour in natural populations. Positive selection on low-armour alleles at the Ectodysplasin ( Eda ) locus in threespine stickleback has led to the repeated evolution of reduced armour, following freshwater colonization by fully armoured marine sticklebacks. This adaptive divergence in armour between marine and freshwater populations would be facilitated if the low allele conferred a behavioural preference for freshwater environments. We experimentally tested whether the low allele is associated with preference for freshwater by measuring the preference of each Eda genotype for freshwater versus saltwater after acclimation to either salinity. We found no association between the Eda low allele and preference for freshwater. Instead, the low allele was significantly associated with a reduced preference for the acclimation environment. This behaviour may facilitate the colonization of freshwater habitats from the sea, but could also hinder local adaptation by promoting migration of low alleles between marine and freshwater environments.

scholarly journals Walk the line: 600000 years of molar evolution constrained by allometry in the fossil rodent Mimomys savini

2014 ◽  
Vol 369 (1649) ◽  
pp. 20140057 ◽  
Author(s):  
Cyril Firmat ◽  
Iván Lozano-Fernández ◽  
Jordi Agustí ◽  
Geir H. Bolstad ◽  
Gloria Cuenca-Bescós ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Morphological Traits ◽  
Growth Regulation ◽  
Rodent Species ◽  
Evolutionary Divergence ◽  
Allometric Relationships ◽  
Evolutionary Allometry ◽  
Dental Measurements ◽  
Lower Molar

The allometric-constraint hypothesis states that evolutionary divergence of morphological traits is restricted by integrated growth regulation. In this study, we test this hypothesis on a time-calibrated and well-documented palaeontological sequence of dental measurements on the Pleistocene arvicoline rodent species Mimomys savini from the Iberian Peninsula. Based on 507 specimens representing nine populations regularly spaced over 600 000 years, we compare static (within-population) and evolutionary (among-population) allometric slopes between the width and the length of the first lower molar. We find that the static allometric slope remains evolutionary stable and predicts the evolutionary allometry quite well. These results support the hypothesis that the macroevolutionary divergence of molar traits is constrained by static allometric relationships.

Different Morphological Traits Influence Predator Defense and Space Use inPhysaacuta

2016 ◽  
Vol 34 (2) ◽  
pp. 79-84 ◽  
Author(s):  
Blake Stevison ◽  
Bart Kensinger ◽  
Barney Luttbeg
Keyword(s):  
Morphological Traits ◽  
Space Use ◽  
Predator Defense

scholarly journals Longer or shorter spines: Reciprocal trait evolution in stickleback via triallelic regulatory changes in Stanniocalcin2a

2021 ◽  
Vol 118 (31) ◽  
pp. e2100694118
Author(s):  
Garrett A. Roberts Kingman ◽  
David Lee ◽  
Felicity C. Jones ◽  
Danielle Desmet ◽  
Michael A. Bell ◽  
...  
Keyword(s):  
Bone Growth ◽  
Natural Populations ◽  
Growth Inhibitor ◽  
Threespine Stickleback ◽  
Wild Populations ◽  
Morphological Effect ◽  
Behavioral Traits ◽  
Regulatory Changes ◽  
Freshwater Environments ◽  
Inhibitor Gene

Vertebrates have repeatedly modified skeletal structures to adapt to their environments. The threespine stickleback is an excellent system for studying skeletal modifications, as different wild populations have either increased or decreased the lengths of their prominent dorsal and pelvic spines in different freshwater environments. Here we identify a regulatory locus that has a major morphological effect on the length of stickleback dorsal and pelvic spines, which we term Maser (major spine enhancer). Maser maps in a closely linked supergene complex that controls multiple armor, feeding, and behavioral traits on chromosome IV. Natural alleles in Maser are differentiated between marine and freshwater sticklebacks; however, alleles found among freshwater populations are also differentiated, with distinct alleles found in short- and long-spined freshwater populations. The distinct freshwater alleles either increase or decrease expression of the bone growth inhibitor gene Stanniocalcin2a in developing spines, providing a simple genetic mechanism for either increasing or decreasing spine lengths in natural populations. Genomic surveys suggest many recurrently differentiated loci in sticklebacks are similarly specialized into three or more distinct alleles, providing multiple ancient standing variants in particular genes that may contribute to a range of phenotypes in different environments.

No short-term effect of salinity on oxygen consumption in threespine stickleback (Gasterosteus aculeatus) from fresh, brackish, and salt water

2012 ◽  
Vol 90 (12) ◽  
pp. 1386-1393 ◽  
Author(s):  
Kyrre Grøtan ◽  
Kjartan Østbye ◽  
Annette Taugbøl ◽  
L. Asbjørn Vøllestad
Keyword(s):  
Oxygen Consumption ◽  
Brackish Water ◽  
Gasterosteus Aculeatus ◽  
Salt Water ◽  
Standard Metabolic Rate ◽  
Threespine Stickleback ◽  
Short Term ◽  
Lateral Plate ◽  
The Cost ◽  
Freshwater Environments

Marine threespine stickleback ( Gasterosteus aculatus L., 1758) have repeatedly colonized Holarctic freshwater environments after the retreat of the Pleistocene glaciers, and based on their ability to move rapidly between salinities have apparently retained a robust osmoregulatory apparatus that can cope with both short- and long-term exposure to non-native salinity environments. Standard metabolic rate (SMR), measured as oxygen consumption at rest, can be used as an indicator of the cost of osmoregulation when fish are exposed to new environmental conditions. Following freshwater colonization, reduction in the number of lateral plates, an antipredator defence structure, is common. Completely plated fish dominate in the sea, low-plated fish dominate in fresh water, and partially plated fish often dominate in brackish water environments. In a laboratory experiment, we estimated SMR in locally adapted populations from salt, brackish, and freshwater environments at three different salinities (0, 15, and 30 practical salinity units (PSU)). In addition, we tested for correlations between SMR and lateral plate number and lateral plate genotype at the Ectodysplasin locus for stickleback originating from the brackish water population. Contrary to our expectations, no differences were found in SMR between any of the experimental groups in our experiment. Apparently, the threespine stickleback is able to move among salinity environments without large short-term metabolic costs, irrespective of their environment of origin.

scholarly journals Ancient genomic variation underlies repeated ecological adaptation in young stickleback populations

2017 ◽  
Author(s):  
Thomas C. Nelson ◽  
William A. Cresko
Keyword(s):  
Genetic Variation ◽  
Local Adaptation ◽  
Northern Hemisphere ◽  
Threespine Stickleback ◽  
Genomic Variation ◽  
Adaptive Mutations ◽  
Freshwater Stickleback ◽  
Genomic Regions ◽  
Stickleback Genome ◽  
Freshwater Environments

ABSTRACTAdaptation in the wild often involves standing genetic variation (SGV), which allows rapid responses to selection on ecological timescales. However, we still know little about how the evolutionary histories and genomic distributions of SGV influence local adaptation in natural populations. Here, we address this knowledge gap using the threespine stickleback fish (Gasterosteus aculeatus) as a model. We extend the popular restriction site-associated DNA sequencing (RAD-seq) method to produce phased haplotypes approaching 700 base pairs (bp) in length at each of over 50,000 loci across the stickleback genome. Parallel adaptation in two geographically isolated freshwater pond populations consistently involved fixation of haplotypes that are identical-by-descent. In these same genomic regions, sequence divergence between marine and freshwater stickleback, as measured by dXY, reaches ten-fold higher than background levels and structures genomic variation into distinct marine and freshwater haplogroups. By combining this dataset with a de novo genome assembly of a related species, the ninespine stickleback (Pungitius pungitius), we find that this habitat-associated divergent variation averages six million years old, nearly twice the genome-wide average. The genomic variation that is involved in recent and rapid local adaptation in stickleback has actually been evolving throughout the 15-million-year history since the two species lineages split. This long history of genomic divergence has maintained large genomic regions of ancient ancestry that include multiple chromosomal inversions and extensive linked variation. These discoveries of ancient genetic variation spread broadly across the genome in stickleback demonstrate how selection on ecological timescales is a result of genome evolution over geological timescales, and vice versa.IMPACT STATEMENTAdaptation to changing environments requires a source of genetic variation. When environments change quickly, species often rely on variation that is already present – so-called standing genetic variation – because new adaptive mutations are just too rare. The threespine stickleback, a small fish species living throughout the Northern Hemisphere, is well-known for its ability to rapidly adapt to new environments. Populations living in coastal oceans are heavily armored with bony plates and spines that protect them from predators. These marine populations have repeatedly invaded and adapted to freshwater environments, losing much of their armor and changing in shape, size, color, and behavior.Adaptation to freshwater environments can occur in mere decades and probably involves lots of standing genetic variation. Indeed, one of the clearest examples we have of adaptation from standing genetic variation comes from a gene, eda, that controls the shifts in armor plating. This discovery involved two surprises that continue to shape our understanding of the genetics of adaptation. First, freshwater stickleback from across the Northern Hemisphere share the same version, or allele, of this gene. Second, the ‘marine’ and ‘freshwater’ alleles arose millions of years ago, even though the freshwater populations studied arose much more recently. While it has been hypothesized that other genes in the stickleback genome may share these patterns, large-scale surveys of genomic variation have been unable to test this prediction directly.Here, we use new sequencing technologies to survey DNA sequence variation across the stickleback genome for patterns like those at the eda gene. We find that every region of the genome associated with marine-freshwater genetic differences shares this pattern to some degree. Moreover, many of these regions are as old or older than eda, stretching back over 10 million years in the past and perhaps even predating the species we now call the threespine stickleback. We conclude that natural selection has maintained this variation over geological timescales and that the same alleles we observe in freshwater stickleback today are the same as those under selection in ancient, now-extinct freshwater habitats. Our findings highlight the need to understand evolution on macroevolutionary timescales to understand and predict adaptation happening in the present day.

Stabilizing pyritic material

1989 ◽  
Vol 4 ◽  
pp. 244-248 ◽  
Author(s):  
Donald L. Wolberg
Keyword(s):  
Significant Contribution ◽  
Organic Materials ◽  
Sedimentary Rocks ◽  
Iron Sulfides ◽  
Decomposition Products ◽  
Iron Minerals ◽  
Pyrite Formation ◽  
Organic Sediments ◽  
Freshwater Environments

The minerals pyrite and marcasite (broadly termed pyritic minerals) are iron sulfides that are common if not ubiquitous in sedimentary rocks, especially in association with organic materials (Berner, 1970). In most marine sedimentary associations, pyrite and marcasite are associated with organic sediments rich in dissolved sulfate and iron minerals. Because of the rapid consumption of sulfate in freshwater environments, however, pyrite formation is more restricted in nonmarine sediments (Berner, 1983). The origin of the sulfur in nonmarine environments must lie within pre-existing rocks or volcanic detritus; a relatively small, but significant contribution may derive from plant and animal decomposition products.

PROFILING OF GUAVA GENOTYPES GROWN IN VIDARBHA CONDITIONS ON THE BASIS OF MORPHOLOGICAL TRAITS

2017 ◽  
Vol 23 (1) ◽  
Author(s):  
R.A. PATIL ◽  
S.G. BHARAD ◽  
S.N. SAWANT
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Morphological Traits ◽  
Considerable Extent ◽  
Fruit Traits ◽  
Breeding Programmes ◽  
Tree Leaf ◽  
Qualitative Characteristics ◽  
Intrapopulation Diversity

Assessment of genetic diversity in the available germplasm is the prerequisite for development of improved genotypes through planned breeding programmes. In the view of this Forty-eight genotypes of seedling origin guava along with 1 check (L-49/Sardar) collected and conserved at germplasm block, Main Garden, Department of Horticulture, Dr. P. D. A. University, Akola were evaluated for genetic variability and diversity based on the qualitative characteristics. The genotypes were evaluated for sixteen morphological traitsviz. tree, leaf, floral and fruit traits. Results Show considerable extent of variability amongst the 49 genotypes in each traits. A sizeable amount of intrapopulation diversity recorded can be used to identify diverse parents which can be utilized in hybridization programmes.

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