scholarly journals Behavioural adaptations in egg laying ancestors facilitate evolutionary transitions to live birth

2021 ◽  
Author(s):  
Amanda K. Pettersen ◽  
Nathalie Feiner ◽  
Daniel W.A. Noble ◽  
Geoffrey M. While ◽  
Charlie K. Cornwallis ◽  
...  
Keyword(s):  
Live Birth ◽  
Phylogenetic Analyses ◽  
Thermal Conditions ◽  
Egg Laying ◽  
Significant Feature ◽  
Evolutionary Transitions ◽  
Egg Retention ◽  
Key Innovation ◽  
Gravid Females ◽  
Thermoregulatory Behaviour

AbstractLive birth is a key innovation that has evolved from egg laying over 100 times in reptiles. One significant feature in this transition is the thermal conditions experienced by developing embryos. Adult lizards and snakes often have preferred body temperatures that can be lethal to developing embryos and should prevent egg retention: how has viviparity repeatedly evolved in the face of this pervasive mismatch? Here we resolve this paradox by conducting phylogenetic analyses using data on thermal preference from 224 species. Thermal mismatches between mothers and offspring are widespread but resolved by gravid females behaviourally down-regulating their body temperature towards the thermal optimum of embryos. Importantly, this thermoregulatory behaviour evolved in ancestral egg-laying species before the evolutionary emergence of live birth. Maternal thermoregulatory behaviour therefore bypasses constraints imposed by a slowly evolving thermal physiology and is likely to have been a key requirement for repeated transitions to live birth.

Impacts of thermal limitation on thermoregulatory behaviour and reproductive success in a lizard

2015 ◽  
Vol 63 (4) ◽  
pp. 225 ◽  
Author(s):  
Jennifer E. Halstead ◽  
Lisa E. Schwanz
Keyword(s):  
Reproductive Success ◽  
Thermal Environment ◽  
Thermal Conditions ◽  
Egg Laying ◽  
Warm Climate ◽  
Lethal Temperatures ◽  
Amphibolurus Muricatus ◽  
Thermoregulatory Behaviour ◽  
Insight Into ◽  
Thermal Limitation

Climatic variation can impact populations of ectotherms by altering reproduction, development, and survival. While a warm climate can provide additional thermal opportunities for ectotherms, excessively warm conditions can restrict activity in avoidance of lethal temperatures. However, ectotherms are not necessarily passive to thermal conditions, and often employ flexible thermoregulatory behaviour to accommodate environmental variation. Here, we examine whether the Australian jacky dragon lizard, Amphibolurus muricatus, can compensate for reduced basking opportunity by basking with greater intensity, and how the thermal environment influences reproductive success in females. Overall, there was no compelling evidence for compensatory thermoregulatory behaviour in response to reduced basking opportunity. Moreover, females with reduced thermal opportunities did not produce eggs, although reproductive success was quite low for both groups, so additional factors may have limited reproduction in the colony. This study allows insight into the links between climate and population persistence in wild animals by providing crucial and rare data on how thermal environment impacts reproduction in an egg-laying lizard.

scholarly journals Exceptional parallelisms characterize the evolutionary transition to live birth in phrynosomatid lizards

2021 ◽  
Author(s):  
Saúl Domínguez-Guerrero ◽  
Fausto Méndez-de la Cruz ◽  
Norma Manríquez-Morán ◽  
Mark Olson ◽  
Patricia Galina-Tessaro ◽  
...  
Keyword(s):  
Live Birth ◽  
Thermal Environment ◽  
Egg Laying ◽  
Body Temperatures ◽  
Ambient Conditions ◽  
Evolutionary Transitions ◽  
Thermal Habitat ◽  
Cold Environments ◽  
Evolutionary Innovation ◽  
Maternal Protection

Abstract Viviparity is an evolutionary innovation that enhances maternal protection of developing embryos relative to egg-laying ancestors. The behavioral, physiological, morphological, and life history pathways underpinning this innovation, however, remain unclear. We capitalized on the repeated origin of viviparity in phrynosomatid lizards to tease apart the phenotypic patterns associated with evolutionary transitions to live birth. We detected tandem reductions in mass-specific metabolic rate and mass-specific production in viviparous lineages, in turn reflecting decreases in thermal physiology and fecundity, respectively. These pathways reduce the energetic burden of viviparity without concomitant reductions in offspring body size. Although viviparous lizards are more prevalent in cold environments, transitions in thermal habitat only weakly predict parity mode evolution. Likewise, only cold tolerance adapts rapidly to thermal environment. Heat tolerance and preferred body temperatures track the thermal environment, but with a lag at million-year timescales. This lag likely reflects behavioral buffering: viviparous lizards thermoregulate to low body temperatures, regardless of ambient conditions. Rather than representing an adaptation to cold climates, the lower thermal and metabolic physiology of viviparous species are likely an energetic adjustment for reproduction that facilitated their prolific colonization of cooler environments.

scholarly journals Social modulation of oogenesis and egg-laying in Drosophila melanogaster

2021 ◽  
Author(s):  
Bailly Tiphaine ◽  
Philip Kohlmeier ◽  
Rampal Etienne ◽  
Bregje Wertheim ◽  
Jean-Christophe Billeter
Keyword(s):  
Drosophila Melanogaster ◽  
Social Context ◽  
Social Systems ◽  
Fruit Fly ◽  
Egg Laying ◽  
Physiological Adaptation ◽  
Group Members ◽  
Selection For ◽  
Underlying Mechanisms ◽  
Gravid Females

Being part of a group facilitates cooperation between group members, but also creates competition for limited resources. This conundrum is problematic for gravid females who benefit from being in a group, but whose future offspring may struggle for access to nutrition in larger groups. Females should thus modulate their reproductive output depending on their social context. Although social-context dependent modulation of reproduction is documented in a broad range of species, its underlying mechanisms and functions are poorly understood. In the fruit fly Drosophila melanogaster, females actively attract conspecifics to lay eggs on the same resources, generating groups in which individuals may cooperate or compete. The tractability of the genetics of this species allows dissecting the mechanisms underlying physiological adaptation to their social context. Here, we show that females produce eggs increasingly faster as group size increases. By laying eggs faster in group than alone, females appear to reduce competition between offspring and increase their likelihood of survival. In addition, females in a group lay their eggs during the light phase of the day, while isolated females lay them during the night. We show that responses to the presence of others are determined by vision through the motion detection pathway and that flies from any sex, mating status or species can trigger these responses. The mechanisms of this modulation of egg-laying by group is connected to a lifting of the inhibition of light on oogenesis and egg-laying by stimulating hormonal pathways involving juvenile hormone. Because modulation of reproduction by social context is a hallmark of animals with higher levels of sociality, our findings represent a protosocial mechanism in a species considered solitary that may have been the target of selection for the evolution of more complex social systems.

Description of Phasmarhabditis californica n. sp. and first report of P. papillosa (Nematoda: Rhabditidae) from invasive slugs in the USA

Nematology ◽  
2016 ◽  
Vol 18 (2) ◽  
pp. 175-193 ◽  
Author(s):  
Irma Tandingan De Ley ◽  
Oleksandr Holovachov ◽  
Rory J. Mc Donnell ◽  
Wim Bert ◽  
Timothy D. Paine ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Egg Laying ◽  
The Body ◽  
Lsu Rdna ◽  
New Taxon ◽  
Sequence Alignments ◽  
Single Male ◽  
The Usa ◽  
Basal Bulb

A new species ofPhasmarhabditisand the known speciesP. papillosawere isolated from cadavers of invasive slugs in California.Phasmarhabditis papillosais the type of the genus and has not previously been reported from the Americas. Both species are characterised based on morphology, morphometrics and molecular data. Molecular phylogenies were inferred from concatenated DNA sequence alignments of nearly complete SSU and the D2-D3 domains of the LSU rDNA.Phasmarhabditis californican. sp. is characterised by a robust body, mature egg-laying specimens almost spindle-shaped when relaxed, 1.5 (1.3-1.8) mm long, tapering to a bluntly rounded anterior end with stoma about as long as lip region diam., six inner labial papillae and four outer cephalic papillae, pharynx with rounded to pyriform basal bulb, vulva located halfway along the body, hermaphroditic, didelphic, amphidelphic, and short, conoid tail constricted at one-third its length with prominent phasmids. Not a single male was found among five strains.Phasmarhabditis papillosais gonochoristic and has a longer isthmus, pyriform basal bulb and longer, dome-shaped spicate female tail constricted halfway along its length. Sequence analysis revealed unambiguous autapomorphies forP. papillosaandP. californican. sp. Phylogenetic analyses placed these two species in a monophyletic clade comprisingPhasmarhabditisspecies and other gastropod-parasitic taxa. Morphology, genetic distance, reproductive strategy and nucleotide autapomorphies support the new taxon.

Egg Retention, Rainfall and Egg Laying in a Tropical Lizard Anolis aeneus

Copeia ◽  
1976 ◽  
Vol 1976 (4) ◽  
pp. 759 ◽  
Author(s):  
Judy A. Stamps
Keyword(s):  
Egg Laying ◽  
Egg Retention

scholarly journals Repeated use of high risk nesting areas in the European whip snake, Hierophis viridiflavus

2021 ◽  
pp. 142-150
Author(s):  
Xavier Bonnet
Keyword(s):  
High Risk ◽  
Critical Factor ◽  
Egg Laying ◽  
Road Mortality ◽  
Nest Site Fidelity ◽  
Relative Safety ◽  
Report Data ◽  
Repeated Use ◽  
Gravid Females ◽  
Whip Snake

Oviparous snakes deposit their egg clutches in sites sheltered from predation and from strong thermal and hydric fluctuations. Appropriate laying sites with optimum thermal and hydric conditions are generally scarce and are not necessarily localised in the home range. Thus, many gravid females undertake extensive trips for oviposition, and many may converge at the best egg laying sites. Dispersal mortality of neonates post-hatchling is also a critical factor. Assessing the parameters involved in this intergenerational trade-off is difficult however, and no study has succeeded in embracing all of them. Here we report data indicating that gravid females of the highly mobile European whip snake, Hierophis viridiflavus exhibit nest site fidelity whereby they repeatedly deposit their eggs in cavities under sealed roads over many decades. These anthropogenic structures provide benefits of relative safety and suitable incubation conditions (due to the protective asphalted layer?), but they expose both females and neonates to high risk of road mortality. Artificial laying sites constructed at appropriate distances from busy roads, along with artificial continuous well protected pathways (e.g. dense hedges) that connect risky laying sites to safer areas, should be constructed.

scholarly journals Plasticity of preferred body temperatures as means of coping with climate change?

2011 ◽  
Vol 8 (2) ◽  
pp. 262-265 ◽  
Author(s):  
Lumír Gvoždík
Keyword(s):  
Climate Change ◽  
Adaptive Capacity ◽  
Thermal Environment ◽  
Global Climate ◽  
Thermal Conditions ◽  
Body Temperatures ◽  
Widespread Occurrence ◽  
The Impact ◽  
Thermoregulatory Behaviour

Thermoregulatory behaviour represents an important component of ectotherm non-genetic adaptive capacity that mitigates the impact of ongoing climate change. The buffering role of behavioural thermoregulation has been attributed solely to the ability to maintain near optimal body temperature for sufficiently extended periods under altered thermal conditions. The widespread occurrence of plastic modification of target temperatures that an ectotherm aims to achieve (preferred body temperatures) has been largely overlooked. I argue that plasticity of target temperatures may significantly contribute to an ectotherm's adaptive capacity. Its contribution to population persistence depends on both the effectiveness of acute thermoregulatory adjustments (reactivity) in buffering selection pressures in a changing thermal environment, and the total costs of thermoregulation (i.e. reactivity and plasticity) in a given environment. The direction and magnitude of plastic shifts in preferred body temperatures can be incorporated into mechanistic models, to improve predictions of the impact of global climate change on ectotherm populations.

Orientation and homing behavior as a measure of affinity for the home range in two species of Iguanid lizards

1991 ◽  
Vol 12 (4) ◽  
pp. 373-384 ◽  
Author(s):  
Craig Guyer
Keyword(s):  
Home Range ◽  
Life Histories ◽  
Egg Laying ◽  
Single Site ◽  
Long Distance ◽  
Homing Behavior ◽  
Sceloporus Graciosus ◽  
Gravid Females ◽  
The Relationship ◽  
Natural Means

AbstractThe relationship between home range affinity and homing ability was studied in Phrynosoma douglassi and Sceloporus graciosus in southeastern Idaho. Movement patterns for P. douglassi were typical of an animal moving from one site of activity to other sites, whereas S. graciosus movements were typical of an animal using a single site of activity. Only S. graciosus was able to orient towards the home range when displaced, indicating an affinity for this site. Adult S. graciosus oriented and homed more consistently than did juveniles. P. douglassi did not orient homeward when displaced and returned less frequently than did S. graciosus. Recapture locations along with data regarding homeward orientation and homing indicate that P. douglassi has a lesser affinity than does S. graciosus for the home range. Some gravid females of both species left the home range to deposit eggs or young and later returned. Use of areas outside the home range for egg-laying and birthing and movements out of the home range resulting from chases by predators may represent natural means of displacement that select for homing behavior. Because most lizards experience only short displacements during their life histories, long distance homing reported for snakes, turtles, and salamanders is absent.

Sign in / Sign up

Export Citation Format

Share Document