scholarly journals Independent evolution towards large body size in the distinctive Faroe Island mice

2019 ◽  
Author(s):  
Ricardo Wilches ◽  
William H. Beluch ◽  
Ellen McConnell ◽  
Diethard Tautz ◽  
Yingguang Frank Chan
Keyword(s):  
Body Size ◽  
Meta Analysis ◽  
Small Body ◽  
Laboratory Mouse ◽  
Large Body ◽  
Size Variation ◽  
Island Population ◽  
Large Body Size ◽  
Multiple Loci ◽  
Similar Phenotype

AbstractMost traits in nature involve the collective action of many genes. Traits that evolve repeatedly are particularly revealing about how selection may act on traits. In mice, large body size has evolved repeatedly on islands and under artificial selection in the laboratory. Identifying the loci and genes involved in this process may shed light on the evolution of complex, polygenic traits. Here, we have mapped the genetic basis of body size variation by making a genetic cross between mice from the Faroe Islands, which are among the largest and most distinctive populations of mice in the world, and a laboratory mouse strain selected for small body size, SM/J. Using this F2 intercross of 841 animals, we have identified 102 loci controlling various aspects of body size, weight and growth hormone levels. By comparing against other studies, including the use of a joint meta-analysis, we found that the loci involved in the evolution of large size in the Faroese mice were largely independent from those of a different island population or other laboratory strains. We conclude that colonization bottleneck, historical hybridization, or the redundancy between multiple loci have resulted in the Faroese mice achieving an outwardly similar phenotype through a distinct evolutionary path.

scholarly journals Independent evolution towards larger body size in the distinctive Faroe Island mice

2021 ◽  
Author(s):  
Ricardo Wilches ◽  
William H Beluch ◽  
Ellen McConnell ◽  
Diethard Tautz ◽  
Yingguang Frank Chan
Keyword(s):  
Body Size ◽  
Meta Analysis ◽  
Small Body ◽  
Laboratory Mouse ◽  
Large Body ◽  
Natural Populations ◽  
Size Variation ◽  
Phenotypic Traits ◽  
Island Population ◽  
Multiple Loci

Abstract Most phenotypic traits in nature involve the collective action of many genes. Traits that evolve repeatedly are particularly useful for understanding how selection may act on changing trait values. In mice, large body size has evolved repeatedly on islands and under artificial selection in the laboratory. Identifying the loci and genes involved in this process may shed light on the evolution of complex, polygenic traits. Here, we have mapped the genetic basis of body size variation by making a genetic cross between mice from the Faroe Islands, which are among the largest and most distinctive natural populations of mice in the world, and a laboratory mouse strain selected for small body size, SM/J. Using this F2 intercross of 841 animals, we have identified 111 loci controlling various aspects of body size, weight and growth hormone levels. By comparing against other studies, including the use of a joint meta-analysis, we found that the loci involved in the evolution of large size in the Faroese mice were largely independent from those of a different island population or other laboratory strains. We hypothesize that colonization bottleneck, historical hybridization, or the redundancy between multiple loci have resulted in the Faroese mice achieving an outwardly similar phenotype through a distinct evolutionary path.

Description of two new species from Venezuela in the highly diverse dipsadine genus Atractus (Serpentes: Colubridae)

2009 ◽  
Vol 30 (2) ◽  
pp. 233-243 ◽  
Author(s):  
Gilson Rivas Fuenmayor ◽  
Paulo Passos ◽  
Cesar Barrio-Amorós
Keyword(s):  
New Species ◽  
Body Size ◽  
Small Body ◽  
Large Body ◽  
Species Description ◽  
Small Body Size ◽  
Single Female ◽  
Large Body Size ◽  
Body Diameter ◽  
Two New Species

AbstractTwo new species of Atractus are described from Venezuela uplands and highlands on two northern Andean cordilleras. Atractus acheronius, known only from Sierra de Perijá, can be distinguished from congeners by having 17 dorsal scale rows, presence of preocular scales, seven upper and lower labials, seven maxillary teeth, 166 ventrals in the single female, 23 subcaudals, dorsum brown with small dark brown dots, large body size, huge body diameter, and small tail size. Atractus multidentatus, known only from north versant of the Cordillera de Mérida, can be distinguished from congeners by having 17 dorsal scale rows, eight upper and lower labials, 18 maxillary teeth, 153 ventrals in the single female, nine subcaudals, dorsum reddish brown with five longitudinal dark brown stripes, small body size, small body diameter, and small tail size. Additionally, a discussion concerning the species description of Atractus based on unique specimens is provided.

scholarly journals Siphonophoridae from Brazilian Amazonia Part 1 – The genus Columbianum Verhoeff, 1941 (Diplopoda, Siphonophorida)

2018 ◽  
Author(s):  
Helen J. Read ◽  
Henrik Enghoff
Keyword(s):  
New Species ◽  
Body Size ◽  
Small Body ◽  
Large Body ◽  
The Body ◽  
Small Body Size ◽  
Large Body Size ◽  
Small Head ◽  
Three New Species ◽  
Seasonally Flooded

A large sample of Siphonophoridae from Brazil was studied; two morphological groups could be distinguished. Here species considered to be from the genus Columbianum Verhoeff, 1941 are examined in detail. The genus is known from Central and South America (Guatemala, Panama, Honduras, Guiana, Colombia, Peru and Brazil) and is characterised by a clear demarcation between head and rostrum in combination with long antennae, clearly surpassing the tip of the rostrum. A list of previously described species considered to belong to the genus is given; three new species are described: C. major sp. nov. has a large body size and a small head, C. nahvalr sp. nov. has a particularly pronounced domed head and a more castellated appearance to the body, C. adisi sp. nov. has a small body size and a very characteristic hind margin to the pleurites. Variation in the state of preservation of specimens hinders a diagnosis, but the examination of the accessory claw and details of the metazonital limbus and pleurite edges are helpful. Unusually for Diplopoda, the male gonopods are not very useful for identification. Ecological comments are given for each new species, one of which, C. adisi sp. nov., is from the seasonally flooded forest and appears to avoid inundation by climbing trees.

scholarly journals Unidirectional response to bidirectional selection on body size. I. Phenotypic, life history and endocrine response

2018 ◽  
Author(s):  
Clémentine Renneville ◽  
Alexis Millot ◽  
Simon Agostini ◽  
David Carmignac ◽  
Gersende Maugars ◽  
...  
Keyword(s):  
Life History ◽  
Body Size ◽  
Small Body ◽  
Large Body ◽  
Detailed Knowledge ◽  
Control Line ◽  
Large Body Size ◽  
Size Dependent ◽  
Body Sizes ◽  
Anthropogenic Perturbations

ABSTRACTAnthropogenic perturbations such as harvesting often select against a large body size and are predicted to induce rapid evolution towards smaller body sizes and earlier maturation. However, body-size evolvability and, hence, adaptability to anthropogenic perturbations remain seldom evaluated in wild populations. Here, we use a laboratory experiment over 6 generations to measure the ability of wild-caught medaka fish (Oryzias latipes) to evolve in response to bidirectional size-dependent selection mimicking opposite harvest regimes. Specifically, we imposed selection against a small body size (Large line), against a large body size (Small line) or random selection (Control line), and measured correlated responses across multiple phenotypic, life-history and endocrine traits. As expected, the Large line evolved faster somatic growth and delayed maturation, but also evolved smaller body sizes at hatch, with no change in average levels of pituitary gene expressions of luteinizing, folliclestimulating or growth (GH) hormones. In contrast, the Small medaka line was unable to evolve smaller body sizes or earlier maturation, but evolved smaller body sizes at hatch and showed marginally-significant signs of increased reproductive investment, including larger egg sizes and elevated pituitary GH production. Natural selection on medaka body size was too weak to significantly hinder the effect of artificial selection, indicating that the asymmetric body-size response to size-dependent selection reflected an asymmetry in body-size evolvability. Our results show that trait evolvability may be contingent upon the direction of selection, and that a detailed knowledge of trait evolutionary potential is needed to forecast population response to anthropogenic change.

scholarly journals Weight and age at puberty in female and male mice of strains selected for large and small body size

1984 ◽  
Vol 44 (1) ◽  
pp. 47-72 ◽  
Author(s):  
D. S. Falconer
Keyword(s):  
Body Size ◽  
Small Groups ◽  
Small Body ◽  
Large Body ◽  
Large Body Size ◽  
Age Dependent ◽  
Size Groups ◽  
The Mean ◽  
Age At Puberty ◽  
Lines Of Evidence

SummaryPuberty was studied in mice of the ninth selected generation of the Q-strain. There were 6 replicate lines selected for large body size (6-week weight), 6 replicates selected for small size and 6 replicate unselected controls. Female puberty was assessed by the opening of the vagina and male puberty by the first copulation plug. The sexes differed in the mean age at puberty, males being older by 13 days in the large, 4 days in the control and 8 days in the small lines. The sexes differed also in the way size affected puberty. In males the large and small lines reached puberty at the same age and both were older than the controls. In females the large lines on average were heavier and younger at puberty than the controls, and the small lines were lighter and older than the controls, though not significantly older. The replicates within each size-group, however, reached puberty at about the same weight, irrespective of their differences in growth rate. Thus, the differences of growth between the large, control and small groups affected both the weight and the age of females at puberty, but the differences of growth between the replicate lines within each size affected only the age at puberty. No explanation was found for this inconsistency between size-groups and replicates. Several lines of evidence led to the conclusion that in females puberty is partly or mainly weight-dependent, whereas in males it is almost wholly age-dependent.

An Exploration of Perception of Body Boundary, Personal Space, and Body Size in Elderly Persons

1979 ◽  
Vol 48 (1) ◽  
pp. 299-308 ◽  
Author(s):  
John R. Phillips
Keyword(s):  
Body Size ◽  
Small Body ◽  
Large Body ◽  
Personal Space ◽  
The Body ◽  
Simulation Technique ◽  
Elderly Persons ◽  
Small Body Size ◽  
Large Body Size ◽  
Body Boundary

A study of 108 elderly persons using the Body Distortion Questionnaire and the personal space simulation technique test did not support hypotheses that elderly persons with a large personal space will have a larger distortion of body boundary, a larger perception of large body size, a smaller perception of small body size, a larger distortion of body size, and a larger body distortion than elderly persons with a small personal space. The analyses with one-tail t tests showed elderly persons with a small personal space have a larger perception of large body size and a larger distortion of body size than elderly persons with a large personal space. When the extremes of personal space were used the results were the same. Males have a larger personal space and greater distortion of skin perceptions than females.

scholarly journals Analysis of quantitative inheritance of body size in mice: V. Effects of small numbers of polygenes on similar genetic backgrounds

1968 ◽  
Vol 11 (3) ◽  
pp. 239-246 ◽  
Author(s):  
C. K. Chai
Keyword(s):  
Body Size ◽  
Small Body ◽  
Large Body ◽  
Quantitative Inheritance ◽  
Small Body Size ◽  
Large Body Size ◽  
Genetic Interpretation ◽  
Body Weights ◽  
The Mean ◽  
The Difference

Sublines carrying isolated polygenes determining body size, developed by selection and repeated backcrossing to the LG and SM strains of mice, were inbred by full-sib matings with concomitant selection to study the inheritance of body size, using birth, weaning (28-day) and 60-day body weights as indices.Mean body weights in those sublines backcrossed to SM and selected for large body size were greater than in those selected for small body size, proving that the difference resulting from seven earlier generations of backcrossing and selection, although small, was genetic and could be fixed by inbreeding. The mean body weights of the sublines selected for small body size drifted upward despite downward selection, a phenomenon thought to be due to the pressure of natural selection outweighing that of artificial selection.In the sublines developed from backcrosses to the LG strain, mice from lines selected for small body size attained a mean body weight greater than that of mice from lines selected for large body size and also than of the parental LG strain. These results were contrary to expectation and a genetic interpretation was offered.

A new species of the subgenus Scheloribates (Topobates) (Acari: Oribatida: Scheloribatidae) from Panama

2020 ◽  
Vol 29 (2) ◽  
pp. 278-283
Author(s):  
S.G. Ermilov
Keyword(s):  
New Species ◽  
Body Size ◽  
Leaf Litter ◽  
Related Species ◽  
Large Body ◽  
Oribatid Mite ◽  
Neotropical Region ◽  
Large Body Size ◽  
First Time ◽  
A New Species

The oribatid mite subgenus Scheloribates (Topobates) Grandjean, 1958, is recorded from the Neotropical region for the first time. A new species of this subgenus is described from the leaf litter collected in Cayo Agua Island, Panama. Scheloribates (Topobates) panamaensis sp. nov. differs from its related species by the very large body size and presence of a strong ventrodistal process on the leg femora II–IV.

scholarly journals Atmospheric Hypoxia Limits Selection for Large Body Size in Insects

PLoS ONE ◽  
2009 ◽  
Vol 4 (1) ◽  
pp. e3876 ◽  
Author(s):  
C. Jaco Klok ◽  
Jon F. Harrison
Keyword(s):  
Body Size ◽  
Large Body ◽  
Large Body Size ◽  
Selection For
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