Thermal and reproductive biology of high and low elevation populations of the lizard Sceloporus scalaris: implications for the evolution of viviparity

Mathies, Tom; Andrews, Robin M.

doi:10.1007/bf00365568

Cited by 100 publications

(82 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This finding is not in accordance with the prediction from intraspecific comparisons of species with wide geographic ranges that larger offspring should be produced in colder localities (Parker and Begon, 1986;Forsman and Shine, 1995;Mathies and Andrews, 1995;Rohr, 1997;Wapstra and Swain, 2001;Ji et al, 2002). Why do females of P. korros from the CZ and DH populations not differ in population egg mass?…”

Section: Discussioncontrasting

confidence: 56%

Reproductive traits of the gray ratsnake Ptyas korros from three geographically distinct populations

Mao

Chen

et al. 2012

Current Zoology

View full text Add to dashboard Cite

We collected gravid gray rat snakes Ptyas korros from three geographically distinct populations in China, Chenzhou (CZ), Jiangshan (JS) and Dinghai (DH), to study geographical variation in female reproductive traits. Egg-laying dates differed among the three populations such that at the most northern latitude egg-laying was latest, and earliest at the most southern latitutde. Clutch size, clutch mass, egg mass, egg shape, within clutch variability in egg sizes and relative clutch mass differed among the three populations, whereas post-oviposition body mass did not. Except for egg-laying date, none of the traits examined varied in a geographically continuous trend. CZ and DH females, although separated by a distance of approximately 1100 km as the crow flies, were similar in nearly all traits examined. JS females were distinguished from CZ and DH females by their higher fecundity (clutch size), greater reproductive output (clutch mass) and more rounded eggs. Our data do not validate the prediction that larger offspring should be produced in colder localities. The absence of an egg size-number trade-off in each of the three populations presumably suggests that P. korros is among species where eggs are well optimized for size within a population [Current Zoology 58 (6): 820-827, 2012].

show abstract

Section: Discussioncontrasting

confidence: 56%

Reproductive traits of the gray ratsnake Ptyas korros from three geographically distinct populations

Mao

Chen

et al. 2012

Current Zoology

View full text Add to dashboard Cite

show abstract

“…Similar patterns of smaller size-specific litters at higher altitudes relative to their lowland counterparts have been reported for populations of various lizard species (Waltner 1991;Mathies and Andrews 1995;Rohr 1997;Lemos-Espinal et al 1998). This phenomenon has been attributed to environmental conditions such as lower resource availability (Rohr 1997).…”

Section: Reproduction and Ecologysupporting

confidence: 76%

“…In addition, sperm competition (Merilä and Sheldon 1998;Jolly and Phillips-Conroy 2001;Preston et al 2002;SchulteHostedde and Millar 2004;Hettyey and Roberts 2006), scramble competition polygyny (Clutton-Brock 1989;Davies 1991), the temporal and spatial distribution of the sexes (Davies 1991;Reynolds 1996) and the operational sex ratio of a species (Greenwood 1980;Hettyey and Roberts 2006) are also influential in determining intraspecific variation in reproductive biology. Such intraspecific geographic variation has been demonstrated in litter size (Hill 1972;Waltner 1991;Mathies and Andrews 1995;Rohr 1997;Lemos-Espinal et al 1998) and testicular size (Merilä and Sheldon 1998;Hettyey et al 2005) due to various ecological and biological factors.…”

Section: Introductionmentioning

confidence: 99%

Distributional range, ecology, and mating system of the Cape mole-rat (Georychus capensis) family Bathyergidae

2017

View full text Add to dashboard Cite

1Distributional range, ecology and mating system of the Cape mole-rat, Georychus capensis family Bathyergidae J. H. Visser, N. C. Bennett and B. Jansen van Vuuren AbstractInterpopulation variation in life-history patterns are influenced by intrinsic and extrinsic factors. Life-history patterns have been intensely studied in the eusocial African bathyergid species, largely neglecting the solitary species. Of these solitary genera, the Cape mole-rat, Georychus capensis (Pallas 1778), is endemic to South Africa with a disjunct distribution across its range. Knowledge regarding this species is rudimentary and therefore this study aimed to investigate the current distribution of the species with particular attention to common ecological variables, differences in body size between localities and sexes, as well as its reproduction and mating system. Georychus is a habitat specialist restricted to specific ecological areas. A lack of sexual size dimorphism and correlation between male testis size and the number of females in the population, suggests a polygynous mating system, facilitated by the spatial distribution of the sexes. A positive relationship between male testes size and the percentage of females in populations sampled suggests that larger sperm reserves (i.e., larger testes) are required in populations with a higher percentage of females. In addition, mating variables (testicular size and litter size) are linked to ecological factors (elevation, aridity, soil-and vegetation type) which could impact mate searching, mating success and food resources.

show abstract

“…In viviparous lizards and snakes, gravid females actively thermoregulate and provide embryos of higher temperatures for development, a behaviour that reduces juvenile mortality as compared to conditions in nest regimes (Braña et al 1991). Viviparity, however, requires modifications to other reproductive features, such as eggshell thickness and clutch size, both decreasing with the degree of viviparity and elevation (Mathies and Andrews 1995). Moreover, pregnant females pay metabolic costs for maintaining higher body temperatures, as visibly appreciable in postpartum body condition.…”

Section: Reptilesmentioning

confidence: 99%

Life-History Responses to the Altitudinal Gradient

Laiolo

Obeso

2017

Advances in Global Change Research

View full text Add to dashboard Cite

We review life-history variation along elevation in animals and plants and illustrate its drivers, mechanisms and constraints. Elevation shapes life histories into suites of correlated traits that are often remarkably convergent among organisms facing the same environmental challenges. Much of the variation observed along elevation is the result of direct physiological sensitivity to temperature and nutrient supply. As a general rule, alpine populations adopt 'slow' life cycles, involving long lifespan, delayed maturity, slow reproductive rates and strong inversions in parental care to enhance the chance of recruitment. Exceptions in both animals and plants are often rooted in evolutionary legacies (e.g. constraints to prolonging cycles in obligatory univoltine taxa) or biogeographic history (e.g. location near trailing or leading edges). Predicting evolutionary trajectories into the future must take into account genetic variability, gene flow and selection strength, which define the potential for local adaptation, as well as the rate of anthropogenic environmental change and species' idiosyncratic reaction norms. Shifts up and down elevation in the past helped maintain genetic differentiation in alpine populations, with slow life cycles contributing to the accumulation of genetic diversity during upward migrations. Gene flow is facilitated by the proximity of neighbouring populations, and global warming is likely to move fast genotypes upwards and reduce some of those constraints dominating alpine life. Demographic buffering or compensation may protect local alpine populations against trends in environmental conditions, but such mechanisms may not last indefinitely if evolutionary trajectories cannot keep pace with rapid changes.

show abstract

Thermal and reproductive biology of high and low elevation populations of the lizard Sceloporus scalaris: implications for the evolution of viviparity

Cited by 100 publications

References 36 publications

Reproductive traits of the gray ratsnake Ptyas korros from three geographically distinct populations

Reproductive traits of the gray ratsnake Ptyas korros from three geographically distinct populations

Distributional range, ecology, and mating system of the Cape mole-rat (Georychus capensis) family Bathyergidae

Life-History Responses to the Altitudinal Gradient

Contact Info

Product

Resources

About