scholarly journals Selection on morphological traits and fluctuating asymmetry by a fungal parasite in the yellow dung fly

2017 ◽  
Author(s):  
Wolf U. Blanckenhorn
Keyword(s):  
Body Size ◽  
Fungal Infection ◽  
Fluctuating Asymmetry ◽  
Large Body ◽  
The Body ◽  
Female Size ◽  
Adult Body Size ◽  
Scathophaga Stercoraria ◽  
Evolutionary Response ◽  
Adult Body

AbstractA Preprint reviewed and recommended by Peer Community Evolutionary Biology: http://dx.doi.org/10.24072/pci.evolbiol.100027Evidence for selective disadvantages of large body size remains scarce in general. Previous phenomenological studies of the yellow dung fly Scathophaga stercoraria have demonstrated strong positive sexual and fecundity selection on male and female size. Nevertheless, the body size of flies from a Swiss study population has declined by almost 10% from 1993 to 2009. Given substantial heritability of body size, this negative evolutionary response of an evidently positively selected trait suggests important selective factors being missed (e.g. size-selective predation or parasitism). A periodic epidemic outbreak of the fungus Entomophthora scatophagae allowedassessment of selection exerted by this parasite fatal to adult flies. Fungal infection varied over the season from ca. 50% in the cooler and more humid spring and autumn to almost 0% in summer. The probability of dying from fungal infection increased with adult body size. All infected females died before laying eggs, so there was no fungus impact on female fecundity beyond its impact on mortality. Large males showed the typical mating advantage in the field, but this pattern of positive sexual selection was nullified by fungal infection. Mean fluctuating asymmetry of paired appendages (legs, wings) did not affect the viability, fecundity or mating success of yellow dung flies in the field. This study demonstrates rare parasite-mediated disadvantages of large adult body size in the field. Reduced ability to combat parasites such as Entomophthora may be an immunity cost of large size in dung flies, although the hypothesized trade-off between fluctuating asymmetry, a presumed indicator of developmental instability and environmental stress, and immunocompetence was not found here.

scholarly journals A fungal parasite selects against body size but not fluctuating asymmetry in Swiss subalpine yellow dung flies

2021 ◽  
Vol 5 ◽  
pp. 27-35
Author(s):  
Wolf U. Blanckenhorn
Keyword(s):  
Body Size ◽  
Fungal Infection ◽  
Fluctuating Asymmetry ◽  
Large Body ◽  
The Body ◽  
Female Size ◽  
Large Body Size ◽  
Scathophaga Stercoraria ◽  
Evolutionary Response ◽  
Study Population

Evidence for selective disadvantages of large body size remains scarce in general. Previous studies of the yellow dung fly Scathophaga stercoraria have demonstrated strong positive sexual and fecundity selection on male and female size. Nevertheless, the body size of flies from a Swiss study population has declined by ~10% 1993–2009. Given substantial heritability of body size, this negative evolutionary response of an evidently positively selected trait suggests important selective factors being missed. An episodic epidemic outbreak of the fungus Entomophthora scatophagae permitted assessment of natural selection exerted by this fatal parasite. Fungal infection varied over the season from ~50% in the cooler and more humid spring and autumn to almost 0% in summer. The probability of dying from fungal infection increased with adult fly body size. Females never laid any eggs after infection, so there was no fungus effect on female fecundity beyond its impact on mortality. Large males showed their typical mating advantage in the field, but this positive sexual selection was nullified by fungal infection. Mean fluctuating asymmetry of paired appendages (legs, wings) did not affect the viability, fecundity or mating success of yellow dung flies in the field. This study documents rare parasite-mediated disadvantages of large-sized flies in the field. Reduced ability to combat parasites such as Entomophthora may be an immunity cost of large body size in dung flies, although the hypothesized trade-off between fluctuating asymmetry, a presumed indicator of developmental instability and environmental stress, and immunocompetence was not found here.

Decrease in litter size in the shrew Crocidura suaveolens (Mammalia, Insectivora) from Corsica (France): Evolutionary response to insularity?

1997 ◽  
Vol 75 (6) ◽  
pp. 954-958 ◽  
Author(s):  
Roger Fons ◽  
Françoise Poitevin ◽  
Josette Catalan ◽  
Henri Croset
Keyword(s):  
Life History ◽  
Body Size ◽  
Litter Size ◽  
Life History Traits ◽  
Breeding Experiment ◽  
Adult Body Size ◽  
Three Generations ◽  
Evolutionary Response ◽  
Adult Body ◽  
Genetically Determined

Populations of the lesser white-toothed shrew, Crocidura suaveolens (Pallas, 1811), from Corsica show an increase in adult body size associated with a decrease in litter size. The average number of embryos in wild Corsican females is smaller (mean 2.6, n = 62) than in mainland females (mean 4.6, n = 173). A breeding experiment was run for 4 years, yielding three generations. Under standard breeding conditions, the differences between island and mainland populations were maintained and were significant (median litter size was 2 for Corsica and 5 for the mainland). These differences in life-history traits were therefore proved experimentally to be genetically determined. Hypotheses concerning the mechanisms responsible for these differences are discussed.

Female size shows similar trends in all clades of the phylum Nematoda

Nematology ◽  
2006 ◽  
Vol 8 (1) ◽  
pp. 111-127 ◽  
Author(s):  
Gregor W. Yeates ◽  
Brian Boag
Keyword(s):  
Body Size ◽  
Female Body ◽  
Nematode Species ◽  
Life Cycles ◽  
Female Size ◽  
Body Volume ◽  
Adult Body Size ◽  
Physical Conditions ◽  
Adult Body ◽  
Unifying Principles

Abstract To seek unifying principles underlying adult body size in the phylum Nematoda, the volume of females of 3150 nematode species in 186 genera has been calculated from published length and diameter information; genera are grouped using the rDNA-based clades of De Ley et al. While the mass of females in some of the clades overlap, there are usually distinct differences within any particular clade between those nematodes that exist in living substrates and those that do not, the latter invariably being smaller. In all five clades (but not Chromadorida) the ability for females to achieve relatively great size is normal, but diminutive females are known from most clades and habitats. Bacterial feeding is common in females in non-living substrates and related females in living substrates, which may represent alternate generations, are often larger. If both groups of females are bacterial feeding it would help to understand the conundrum of whether those in living substrates are larger because they utilise better physical conditions or are larger because they are required to produce more propagules. Female body volume has previously been successfully used in zoogeography and further investigations may include not only adult volume but also address the question of stage-to-stage growth for which earlier studies revealed a paucity of data. This survey of the phylum has not been controlled for phylogeny, apart from the use of clades, and detailed studies could be made within clades. In particular, the effect of substrate, controlled through using species with alternate life cycles, should be tractable.

scholarly journals The impact of maternal uterine genotype on postnatal growth and adult body size in mice.

Genetics ◽  
1989 ◽  
Vol 122 (1) ◽  
pp. 193-203 ◽  
Author(s):  
D E Cowley ◽  
D Pomp ◽  
W R Atchley ◽  
E J Eisen ◽  
D Hawkins-Brown
Keyword(s):  
Body Size ◽  
Embryo Transfer ◽  
Small Body ◽  
Large Body ◽  
Tail Length ◽  
Postnatal Growth ◽  
Adult Body Size ◽  
Adult Mice ◽  
Adult Body ◽  
The Impact

Abstract Embryo transfers were used to demonstrate that the genotype of the mother providing the uterine developmental environment significantly influences postnatal growth and adult body size of her progeny. Irrespective of their own genotype, mouse embryos transferred into the uterus of an inbred strain with large body size (C3H) had greater body weights, longer tails and higher growth rates than those transferred into the uterus of a strain with small body size (SWR). Uterine heterosis on body size was smaller than progeny heterosis, and both progeny and uterine heterosis persisted in adult mice. Uterine litter size was significantly negatively associated with body weight, tail length, growth rate and the timing of developmental events. The inbred SWR strain was more sensitive to the embryo transfer procedure than the C3H strain, but effects due to embryo transfer were moderate. Prenatal uterine effects have ramifications for biotechnologies utilizing embryo transfer as well as predictions about evolutionary change by selection.

scholarly journals Large body size in the dog is associated with transient GH excess at a young age

2001 ◽  
Vol 170 (2) ◽  
pp. 479-484 ◽  
Author(s):  
RP Favier ◽  
JA Mol ◽  
HS Kooistra ◽  
A Rijnberk
Keyword(s):  
Body Size ◽  
Large Body ◽  
Young Age ◽  
Adult Body Size ◽  
Significant Difference ◽  
Adult Body ◽  
Igf I ◽  
Basal Plasma ◽  
The Mean ◽  
Plasma Gh

The main determinants of body size are GH and IGFs. The aim of this study was to investigate whether differences in adult body size of medium-sized and giant dog breeds can be explained by differences in GH release and/or in plasma IGF-I and IGF-II concentrations at a young age. The basal plasma concentrations of GH, IGF-I and IGF-II were determined once weekly in six Great Danes and six beagles from the age of 6 weeks until the age of 24 weeks. In addition, the 6 h secretory profile of GH was determined every 2 weeks. Basal plasma GH concentrations as well as the total area under the curve (AUC) and the AUC above the baseline for GH were significantly higher in Great Danes than in beagles of the same age. In contrast, plasma IGF-I and IGF-II concentrations did not differ significantly between the two breeds. Compared with values in adults, the basal plasma GH concentrations were high until the age of 7 weeks in the beagles, whereas in the Great Danes the basal plasma GH levels remained high during the entire observation period, albeit with a gradual decline. The mean frequency and the mean amplitude of GH pulses tended to be higher in Great Danes than in beagles, although a significant difference was only reached at the age of 19 and 23 weeks for the frequency and at the ages of 9, 11 and 13 weeks for the amplitude. An age-dependent decrease in pulse frequency occurred in the Great Danes. The results of this study demonstrate that differences in adult body size of medium-sized and giant dog breeds are preceded by differences in GH release and not by differences in circulating IGF-I or IGF-II concentrations. Both young Great Danes and young beagles experience a period of high GH release, but this period persists much longer in Great Danes. It is discussed that this difference may be due to delayed maturation of the inhibitory influences of somatostatin on pituitary GH release in the latter dogs.

Grass-flower thrips of the genus Chirothrips (Thysanoptera: Thripidae), with a key to species from Iran

Zootaxa ◽  
2010 ◽  
Vol 2411 (1) ◽  
pp. 33 ◽  
Author(s):  
KAMBIZ MINAEI ◽  
LAURENCE MOUND
Keyword(s):  
Body Size ◽  
Species Group ◽  
Identification Key ◽  
Key To Species ◽  
Adult Body Size ◽  
Flower Thrips ◽  
New Synonym ◽  
Adult Body ◽  
Structural Differences

Species of the genus Chirothrips Haliday breed and pupate only within grass florets. Each larva is restricted to a single floret, and adult body size is thus presumably related to floret size. Despite this, some Chirothrips species are distinguished only on states that are related to body size. The validity of some commonly recorded members of the C. manicatus species-group, including C. africanus and C. pallidicornis, is therefore considered questionable. Character states that have been used to define the genus Agrostothrips Hood are shown to be variable, and this genus is placed as a new synonym of Chirothrips. An identification key, based on illustrated structural differences, is provided to the Chirothrips known from Iran: C. aculeatus, C. atricorpus, C. kurdistanus, C. manicatus, C. meridionalis and C. molestus.

scholarly journals New records of ring nematodes, Bakernema enormese n. sp. and Criconema (Nothocriconemella) graminicola Loof, Wouts & Yeates, 1997 (Nematoda: Criconematidae) from natural forests of Vietnam

2019 ◽  
Vol 41 (3) ◽  
Author(s):  
Nguyen Ngoc Chau
Keyword(s):  
New Species ◽  
Body Size ◽  
New Records ◽  
Large Body ◽  
Lateral View ◽  
The Body ◽  
Natural Forests ◽  
Large Body Size ◽  
Stylet Length ◽  
North Vietnam

Bakernema enormese sp. n., collected from rhizosphere of forest wood trees in Muong Phang, Dien Bien Province (north Vietnam) is described and illustrated. The new species is characterized by large body size and stylet. In general, this new species is close to two existing species of the same genus, B. inaequale and B. dauniense by cuticle structure in transparent membranous projections which appear in lateral view as spine-like structures on each annulus. These structure arranged into several rows along the body. In morphology, the new species differs from B. inaequale and B. dauniense  by body and stylet length, i.e. 609–842 µm and 143.5–150 µm vs. 391–578 µm and 59–74 µm for B. inaequale and vs. 391–461 µm and 65–74 µm for B. dauniense. In addition, new species can be distinguished from B. inaequale by the longer membranous projection, 8–12 vs. 6–10 µm and vagina shape, curved vs. sigmoid. From B. dauniense, the new species differs by the much longer membranous projection, 8–12 vs. 1.4–2.2 µm and less number annules between vulva and tail end (RV), 3–4 vs. 7.8 annules. The presence of Criconema (Nothocriconemella) graminicola Loof, Wouts & Yeates, in Vietnam with morphometrics, illustrators and remarks given.

scholarly journals Childhood retardation resulting in reduction of adult body size due to lesser adolescent skeletal delay

1970 ◽  
Vol 33 (3) ◽  
pp. 325-336 ◽  
Author(s):  
A. Roberto Frisancho ◽  
Stanley M. Garn ◽  
Werner Ascoli
Keyword(s):  
Body Size ◽  
Adult Body Size ◽  
Adult Body
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