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1.
Lenka Halámková James A. Schulte II Tom A. Langen 《Biological journal of the Linnean Society. Linnean Society of London》2013,108(2):396-413
Macroevolutionary patterns of sexual size dimorphism (SSD) indicate how sexual selection, natural selection, and genetic and developmental constraints mold sex differences in body size. One putative pattern, known as Rensch's rule, posits that, among species with female‐larger SSD, the relative degree of SSD declines with species' body size, whereas, among male‐larger SSD species, relative SSD increases with size. Using a dataset of 196 chelonian species from all fourteen families, we investigated the correlation in body size evolution between male and female Chelonia and the validity of Rensch's rule for the taxon and within its major clades. We conclude that male–female correlations in body size evolution are high, although these correlations differ among chelonian families. Overall, SSD scales isometrically with body size; Rensch's rule is valid for only one family, Testudinidae (tortoises). Because macroevolutionary patterns of SSD can vary markedly among clades, even in a taxon as morphologically conservative as Testudines, one must guard against inappropriately pooling clades in comparative studies of SSD. The results of the present study also indicate that regression models that assume the x‐variable (e.g. male body size) is measured without statistical error, although frequently reported, will result in erroneous conclusions about phylogenetic trends in sexual size dimorphism. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 108 , 396–413. 相似文献
2.
Phylogenetic comparative methods were used to analyze the consequences of sexual selection on canine size and canine size dimorphism in primates. Our analyses of previously published body mass and canine size data revealed that the degree of sexual selection is correlated with canine size dimorphism, as well as with canine size in both sexes, in haplorhine but not in strepsirrhine primates. Consistent with these results, male and female canine size was found to be highly correlated in all primates. Since canine dimorphism and canine size in both sexes in haplorhines were found to be not only related to mating system but also to body size and body size dimorphism (characters which are also subject to or the result of sexual selection), it was not apparent whether the degree of canine dimorphism is the result of sexual selection on canine size itself, or whether canine dimorphism is instead a consequence of selection on body size, or vice versa. To distinguish among these possibilities, we conducted matched-pairs analyses on canine size after correcting for the effects of body size. These tests revealed significant effects of sexual selection on relative canine size, indicating that canine size is more important in haplorhine male-male competition than body size. Further analyses showed, however, that it was not possible to detect any evolutionary lag between canine size and body size, or between canine size dimorphism and body size dimorphism. Additional support for the notion of special selection on canine size consisted of allometric relationships in haplorhines between canine size and canine size dimorphism in males, as well as between canine size dimorphism and body size dimorphism. In conclusion, these analyses revealed that the effects of sexual selection on canine size are stronger than those on body size, perhaps indicating that canines are more important than body size in haplorhine male-male competition. 相似文献
3.
Ren‐Chung Cheng Matjaž Kuntner 《Evolution; international journal of organic evolution》2014,68(10):2861-2872
Sexual dimorphism describes substantial differences between male and female phenotypes. In spiders, sexual dimorphism research almost exclusively focuses on size, and recent studies have recovered steady evolutionary size increases in females, and independent evolutionary size changes in males. Their discordance is due to negative allometric size patterns caused by different selection pressures on male and female sizes (converse Rensch's rule). Here, we investigated macroevolutionary patterns of sexual size dimorphism (SSD) in Argiopinae, a global lineage of orb‐weaving spiders with varying degrees of SSD. We devised a Bayesian and maximum‐likelihood molecular species‐level phylogeny, and then used it to reconstruct sex‐specific size evolution, to examine general hypotheses and different models of size evolution, to test for sexual size coevolution, and to examine allometric patterns of SSD. Our results, revealing ancestral moderate sizes and SSD, failed to reject the Brownian motion model, which suggests a nondirectional size evolution. Contrary to predictions, male and female sizes were phylogenetically correlated, and SSD evolution was isometric. We interpret these results to question the classical explanations of female‐biased SSD via fecundity, gravity, and differential mortality. In argiopines, SSD evolution may be driven by these or additional selection mechanisms, but perhaps at different phylogenetic scales. 相似文献
4.
CANDACE M. DAVIS V. LOUISE ROTH 《Biological journal of the Linnean Society. Linnean Society of London》2008,95(1):141-156
In mammals, ‘female‐biased’ sexual size dimorphism (SSD), in which females are larger than males, is uncommon. In the present study, we examined Sylvilagus, a purported case of female‐biased SSD, for evolutionary correlations among species between SSD, body‐size, and life‐history variables. We find that: (1) although most species are female‐biased, the degree and direction of SSD vary more than was previously recognized and (2) the degree of SSD decreases with increasing body size. Hence, Sylvilagus provides a new example, unusual for a female‐biased taxon, in which allometry for SSD is consistent with ‘Rensch's Rule’. As a corollary to Rensch's Rule, we observe that changes in SSD in Sylvilagus are typically associated with larger, more significant changes in males than females. Female‐biased SSD could be produced by selection for larger females, smaller males, or both. Although larger female size may be related to high fecundity and the extremely rapid fetal and neonatal growth in Sylvilagus, we find little evidence for a correlation between SSD and various fecundity‐related traits in among‐species comparisons. Smaller male size may confer greater reproductive success through greater mobility and reduced energetic requirements. We propose that a suite of traits (female dispersion, large male home ranges, reduced aggression, and a promiscuous mating system) has favoured smaller males and thus influenced the evolution of SSD in cottontails. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 141–156. 相似文献
5.
Dale J Dunn PO Figuerola J Lislevand T Székely T Whittingham LA 《Proceedings. Biological sciences / The Royal Society》2007,274(1628):2971-2979
In 1950, Rensch first described that in groups of related species, sexual size dimorphism is more pronounced in larger species. This widespread and fundamental allometric relationship is now commonly referred to as 'Rensch's rule'. However, despite numerous recent studies, we still do not have a general explanation for this allometry. Here we report that patterns of allometry in over 5300 bird species demonstrate that Rensch's rule is driven by a correlated evolutionary change in females to directional sexual selection on males. First, in detailed multivariate analysis, the strength of sexual selection was, by far, the strongest predictor of allometry. This was found to be the case even after controlling for numerous potential confounding factors, such as overall size, degree of ornamentation, phylogenetic history and the range and degree of size dimorphism. Second, in groups where sexual selection is stronger in females, allometry consistently goes in the opposite direction to Rensch's rule. Taken together, these results provide the first clear solution to the long-standing evolutionary problem of allometry for sexual size dimorphism: sexual selection causes size dimorphism to correlate with species size. 相似文献
6.
JAKUB POLK DANIEL FRYNTA 《Biological journal of the Linnean Society. Linnean Society of London》2009,98(4):872-883
Sexual size dimorphism (SSD) is a widespread phenomenon in different animal taxa, including the subfamily of goats and sheep (Caprinae), which belongs to the most dimorphic mammalian groups. Rensch's rule describes the pattern of SSD, claiming that larger species generally exhibits higher male to female body size ratio. Agreement with Rensch's rule is manifested by slope of the allometric relationship between male and female body size exceeding one. To test this rule, we analysed the data available in the literature on adult body mass of males and females in domestic goat and sheep breeds (169 and 303, respectively) and 37 wild species/subspecies of the subfamily Caprinae. According to the current phylogenetical hypotheses, there are six distinct monophyletic groups with different levels of SSD (expressed as M/F): (1) wild goats (1.83); (2) wild sheep (1.67); (3) non‐European chamoises, including Ovibos moschatus (1.18); (4) European chamoises (1.27); (5) Budorcas taxicolor (1.01); and (6) Pantholops hodgsonii (1.65). Domestication has led to a remarkable decline in SSD of both domestic goats (1.36) and sheep (1.41). The highest regression slope of the relationship between male and female body size is that estimated for wild goats (1.32), followed by wild sheep (1.24), non‐European chamoises (1.14), domestic sheep (1.13), and domestic goats (1.10). Nevertheless, only the last two values are statistically different from one and thus corroborate Rensch's rule. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98 , 872–883. 相似文献
7.
The climate is often evoked to explain broad‐scale clines of body size, yet its involvement in the processes that generate size inequality in the two sexes (sexual size dimorphism) remains elusive. Here, we analyse climatic clines of sexual size dimorphism along a wide elevation gradient (i) among grasshopper species in a phylogenetically controlled scenario and (ii) within species differing in distribution and cold tolerance, to highlight patterns generated at different time scales, mainly evolutionary (among species or higher taxa) and ontogenetic or microevolutionary (within species). At the interspecific level, grasshoppers were slightly smaller and less dimorphic at high elevations. These clines were associated with gradients of precipitation and sun exposure, which are likely indicators of other factors that directly exert selective pressures, such as resource availability and conditions for effective thermoregulation. Within species, we found a positive effect of temperature and a negative effect of elevation on body size, especially on condition‐dependent measures of body size (total body length rather than hind femur length) and in species inhabiting the highest elevations. In spite of a certain degree of species‐specific variation, females tended to adjust their body size more often than males, suggesting that body size in females can evolve faster among species and can be more plastic or dependent on nutritional conditions within species living in adverse climates. Natural selection on female body size may therefore prevail over sexual selection on male body size in alpine environments, and abiotic factors may trigger consistent phenotypic patterns across taxonomic scales. 相似文献
8.
Ehab Abouheif 《Evolution; international journal of organic evolution》1998,52(4):1197-1204
One of the toughest problems facing comparative biology is the paucity of robust phylogenetic hypotheses for many taxonomic groups. Martins (1996) proposed a method to analyze comparative data in the absence of a known phylogeny using randomly generated trees. Before applying this method, however, researchers should be aware that (1) parameter estimates derived from this method essentially assume a star phylogeny, and thus, estimate the same evolutionary regression or correlation coefficient as traditional cross-species analyses; and (2) statistical conclusions derived from this method may be so conservative as to mask evolutionary patterns, such as Rensch's rule, and should be interpreted with caution. 相似文献
9.
Sexual dimorphism is prevalent in most living organisms. The difference in size between sexes of a given species is generally known as sexual size dimorphism (SSD). The magnitude of the SSD is determined by Rensch's rule where size dimorphism increases with increasing body size when the male is the larger sex and decreases with increasing average body size when the female is the larger sex. The unique underground environment that zokors (Eospalax baileyi) live under in the severe habitat of the Qinghai‐Tibetan Plateau (QTP) could create SSD selection pressures that may or may not be supported by Rensch's rule, making this scientific question worthy of investigation. In this study, we investigated the individual variation between sexes in body size and SSD of plateau zokors using measurements of 19 morphological traits. We also investigated the evolutionary mechanisms underlying SSD in plateau zokors. Moreover, we applied Rensch's rule to all extant zokor species. Our results showed male‐biased SSD in plateau zokors: The body‐ and head‐related measurements were greater in males than in females. Linear regression analysis between body length, body weight, and carcass weight showed significant relationships with some traits such as skull length, lower incisor length, and tympanic bulla width, which might support our prediction that males have faster growth rates than females. Further, the SSD pattern corroborated the assumption of Rensch's rule in plateau zokors but not in the other zokor species. Our findings suggest that the natural underground habitat and behavioral differences between sexes can generate selection pressures on male traits and contribute to the evolution of SSD in plateau zokors. 相似文献
10.
Fernandez-Duque E 《American journal of physical anthropology》2011,146(1):38-48
Some monogamous primates are characterized by biparental care, territoriality, and a reduced level of physical dimorphism. In others, the relationship between those behavioral patterns and dimorphism is less clear. I tested Bergmann's and Rensch's rules using Aotus spp. body mass data and I characterized the extent of sexual dimorphism in body mass, dental and physical measurements in a socially monogamous owl monkey population (n = 91 adults) from the Argentinean Gran Chaco. A. azarai azarai from the Argentinean Chaco is larger than the more tropical owl monkey species (r = 0.7, N = 6 species), but there is no apparent increase in sexual dimorphism with increased body mass. The body masses of adult male and female A. a. azarai were remarkably similar (Mean = 1.26 kg); there were no marked sex differences in most skeletal measurements, but males had higher and wider upper and lower canines than did females. Body mass and neck circumference were positively and strongly related (r = 0.533, n = 52), and the body mass of adults was not a reliable indicator of their age (r = 0.03, n = 10). The data illustrate the complexities inherent in examining and summarizing within population variation in skeletal and nonskeletal measurements and contribute to a better understanding of the relationships between monogamous behavioral patterns and sexual dimorphism. 相似文献
11.
Stefan P. W. Walker Mark I. McCormick 《Proceedings. Biological sciences / The Royal Society》2009,276(1671):3335-3343
In 1950, Rensch noted that in clades where males are the larger sex, sexual size dimorphism (SSD) tends to be more pronounced in larger species. This fundamental allometric relationship is now known as ‘Rensch''s rule’. While most researchers attribute Rensch''s rule to sexual selection for male size, experimental evidence is lacking. Here, we suggest that ultimate hypotheses for Rensch''s rule should also apply to groups of individuals and that individual trait plasticity can be used to test those hypotheses experimentally. Specifically, we show that in the sex-changing fish Parapercis cylindrica, larger males have larger harems with larger females, and that SSD increases with harem size. Thus, sexual selection for male body size is the ultimate cause of sexual size allometry. In addition, we experimentally illustrate a positive relationship between polygyny potential and individual growth rate during sex change from female to male. Thus, sexual selection is the ultimate cause of variation in growth rate, and variation in growth rate is the proximate cause of sexual size allometry. Taken together, our results provide compelling evidence in support of the sexual selection hypothesis for Rensch''s rule and highlight the potential importance of individual growth modification in the shaping of morphological patterns in Nature. 相似文献
12.
Animal body size commonly shows a relationship with latitude to the degree that this phenomenon is one of the few ‘rules’ discussed in evolutionary ecology: Bergmann's rule. Although exaggerated secondary sexual traits frequently exhibit interesting relationships with body size (allometries) and are expected to evolve rapidly in response to environmental variation, the way in which allometry might interact with latitude has not been addressed. We present data showing latitudinal variation in body size and weapon allometry for the New Zealand giraffe weevil (Lasiorhynchus barbicornis). Males display an extremely elongated rostrum used as a weapon during fights for access to females. Consistent with Bergmann's rule, mean body size increased with latitude. More interestingly, weapon allometry also varied with latitude, such that lower latitude populations exhibited steeper allometric slopes between weapon and body size. To our knowledge, this is the first study to document a latitudinal cline in weapon allometry and is therefore a novel contribution to the collective work on Bergmann's rule and secondary sexual trait variation. 相似文献
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14.
Bergmann's rule predicts larger body sizes in species living in higher latitudes and altitudes. This rule appears to be valid for endotherms, but its relevance to ectotherm vertebrates has largely been debated. In squamate reptiles (lizards and snakes), only one study, based on Liolaemus species of the boulengeri clade, has provided phylogenetic evidence in favour of Bergmann's clines. We reassessed this model in the same lizard clade, using a more representative measure of species body size and including a larger number of taxa in the sample. We found no evidence to support Bergmann's rule in this lineage. However, these non-significant results appear to be explained only by the inclusion of further species rather than by a different estimation of body size. Analyses conducted on the 16 species included in the previous study always revealed significant relationships between body size and latitude-altitude, whereas, the enlarged sample always rejected the pattern predicted by Bergmann's rule. 相似文献
15.
M'hamed El Mokhefi Gahdab Chakali Noureddine Rahim Lynda Bouchou Andrea Battisti 《Agricultural and Forest Entomology》2021,23(1):23-31
- Body size correlates with several factors such as reproductive fitness, environmental changes, the quality and quantity of food during critical development stages, and the feeding season. For the Palearctic moths of the genus Thaumetopoea (Lepidoptera; Notodontidae), the larval development is crucial and differs between species according to their feeding season; larvae of the pine processionary moth Thaumetopoea pityocampa (Denis & Schiffermüller 1775) feed during winter while larvae of its congeneric cedar processionary moth Thaumetopoea bonjeani (Powell 1922) develop during summer in North Africa.
- This discrepancy in lifecycles leads to different reproductive traits such as egg batch length, number of eggs per batch, eggs protection mechanisms and female body size.
- According to Darwin's fecundity advantage hypothesis (1871), female body size should have a positive influence on reproductive fitness, since larger females supposedly have higher fecundity. The universal allometric scaling phenomenon rule proposed by Rensch (1950) predicts that the degree of sexual size dimorphism tends to decrease with the increase of female body size.
- Here, two morphometrical parameters that is, body size and scale size, estimated from body measurements of individuals of both species, feeding on the same host Atlantic cedar Cedrus atlantica (Manetti & Carrière 1855) (Pinales; Pinaceae) in Algeria were proposed. The aim was to find out traits that might rule the competition for food and space, in particularly fecundity and body size.
- Results of the present study highlight a female-biased sexual size dimorphism in both species. The positive correlation between female body size and fecundity shown in this study weakly supports Darwin's hypothesis. Finally, the intrageneric test performed leads to conclude that Rensch's rule does not hold in the considered species.
16.
Michael A. Schillaci 《American journal of primatology》2010,72(2):152-160
This study examines latitudinal and insular variation in the expression of sexual dimorphism in cranial length in three geographical groupings of Macaca fascicularis. In addition, the relationship between cranial length dimorphism (CLD) and sex‐specific size is examined. The results of the study identified a significant relationship between CLD and latitude for only one of the three geographic groupings. Sex‐specific relationships between cranial length and CLD were detected. The pattern of these relationships varied by geographic grouping. This study is important because it demonstrates that despite very similar levels of CLD in a single primate species, there exists important geographic variability in the correlates of that dimorphism. I suggest that geographically varying ecological factors may influence sex‐specific natural selection and the intensity of CLD in M. fascicularis. Gaining a better understanding of this geographical variability will require that future research examines morphological variation, including CLD, within its corresponding ecological and social contexts. Such research should be comparative, and incorporate multiple geographically separated populations with disparate environmental settings. Am. J. Primatol. 72:152–160, 2010. © 2009 Wiley‐Liss, Inc. 相似文献
17.
Alex Slavenko Anat Feldman Allen Allison Aaron M. Bauer Monika Bhm Laurent Chirio Guarino R. Colli Indraneil Das Tiffany M. Doan Matthew LeBreton Marcio Martins Danny Meirte Zoltn T. Nagy Cristiano de C. Nogueira Olivier S. G. Pauwels Daniel Pincheira‐Donoso Uri Roll Philipp Wagner Yuezhao Wang Shai Meiri 《Global Ecology and Biogeography》2019,28(4):471-483
18.
Evgeny S. Roitberg Valentina F. Orlova Nina A. Bulakhova Valentina N. Kuranova Galina V. Eplanova Oleksandr I. Zinenko Oscar Arribas Luk&#x; Kratochvíl Katarina Ljubisavljevi&#x; Vladimir P. Starikov Henk Strijbosch Sylvia Hofmann Olga A. Leontyeva Wolfgang Bhme 《Ecology and evolution》2020,10(11):4531-4561
Reproductive mode, ancestry, and climate are hypothesized to determine body size variation in reptiles but their effects have rarely been estimated simultaneously, especially at the intraspecific level. The common lizard (Zootoca vivipara) occupies almost the entire Northern Eurasia and includes viviparous and oviparous lineages, thus representing an excellent model for such studies. Using body length data for >10,000 individuals from 72 geographically distinct populations over the species' range, we analyzed how sex‐specific adult body size and sexual size dimorphism (SSD) is associated with reproductive mode, lineage identity, and several climatic variables. Variation in male size was low and poorly explained by our predictors. In contrast, female size and SSD varied considerably, demonstrating significant effects of reproductive mode and particularly seasonality. Populations of the western oviparous lineage (northern Spain, south‐western France) exhibited a smaller female size and less female‐biased SSD than those of the western viviparous (France to Eastern Europe) and the eastern viviparous (Eastern Europe to Far East) lineages; this pattern persisted even after controlling for climatic effects. The phenotypic response to seasonality was complex: across the lineages, as well as within the eastern viviparous lineage, female size and SSD increase with increasing seasonality, whereas the western viviparous lineage followed the opposing trends. Altogether, viviparous populations seem to follow a saw‐tooth geographic cline, which might reflect the nonmonotonic relationship of body size at maturity in females with the length of activity season. This relationship is predicted to arise in perennial ectotherms as a response to environmental constraints caused by seasonality of growth and reproduction. The SSD allometry followed the converse of Rensch's rule, a rare pattern for amniotes. Our results provide the first evidence of opposing body size—climate relationships in intraspecific units. 相似文献
19.
We use standardized independent contrasts (SICs) to elucidate the effect of ecology and mating systems on morphological radiation in grouse. The analysis of SICs for 38 skeletal measurements from 20 taxa, showed that changes in mating system had a significant effect on body size of both sexes. Sexual size dimorphism in grouse is consistent with Rensch's rule; the slope of the regression of male vs. female size SICs was 1.4, significantly >1. Changes in habitat were associated with accelerated rates of evolution of body proportions. SICs for male and female scores of size independent factors were directly proportional to each other (slope = 1), indicating extreme similarities between male and female ecology. Females, however, were better adapted to longer, more energy efficient flight than males. Size independent morphological differences among grouse are adaptive and are related to the differences in habitat and foraging behaviour among the species. 相似文献
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