{"id":3663,"date":"2025-04-02T16:12:34","date_gmt":"2025-04-02T14:12:34","guid":{"rendered":"https:\/\/lizardecology.org\/?page_id=3663"},"modified":"2025-04-02T16:12:34","modified_gmt":"2025-04-02T14:12:34","slug":"anr-tipex-project-2024-2028","status":"publish","type":"page","link":"https:\/\/lizardecology.org\/?page_id=3663","title":{"rendered":"ANR TIPEX Project (2024-2028)"},"content":{"rendered":"\n

Tipping points in climate-induced life history plasticity in a reproductively bimodal lizard<\/p>\n\n\n\n

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A project funded by Agence Nationale de la Recherche in France to support a group of six CNRS and University laboratories investigating warming effects on pace-of-life acceleration and senescence.<\/p>\n<\/div>

\"Overall<\/figure><\/div>\n\n\n\n

About the project<\/h2>\n\n\n\n


At the current warming rate, many organisms should go extinct if they are not able to disperse or adapt locally, which often involves plastic responses. In ectotherms, warming influences plastic life history traits with an acceleration of early life production at the expense of longevity and senescence. This may be due to trade-offs involving warming-induced oxidative stress and telomere shortening. Although pace-of-life acceleration may provide short-term benefits, it also increases sensitivity to limited resources, extreme climate events and unusual nighttime thermal conditions. Thus, in an increasingly warmer climate, ectotherms could reach critical physiological thresholds that would precipitate their decline. To date, physiological mechanisms and ecological consequences of this pace-of-life acceleration are poorly characterized. Here, we will combine experimental, observational and analytical approaches to unlock critical gaps in our understanding of thermal plasticity of life history. We will focus on a bimodal reproductive lizard (Zootoca vivipara<\/em>), which offers a unique context to analyze how evolutionary transition between oviparity and viviparity influenced pace-of-life acceleration. Using long-term data sets and surveys across climatic gradients, we will document patterns of pace-of-life acceleration in response to climate warming in the two reproductive modes, focusing on vulnerable populations of the warm margin. In addition, we will perform outdoor and laboratory experiments to identify physiological tipping points in the context of day-night asymmetry of warming and extreme climate events. Given their major potential role in this thermal plasticity, non-energetic trade-offs will be quantified using longitudinal and cross-sectional assays of oxidative stress and telomere length dynamics. Altogether, this project will highlight patterns, mechanisms, and consequences on population viability of pace-of-life acceleration in response to climate warming.<\/p>\n\n\n\n\n\n\n\n

Work packages<\/h2>\n\n\n\n
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WP1 – Project management, communication, open data and animal welfare<\/strong><\/p>\n\n\n\n

In WP1, the project manager will coordinate networking activities, communication and exchange of documents and data. We will organize regular remote meetings emphasizing daily activities and one annual meeting including all participants. Staff recruitment will be managed by each partner in agreement with the coordinator and all implicated partners. The project manager will coordinate the open data and animal welfare policy. External communication will be coordinated by Cistude Nature.<\/p>\n\n\n\n

WP2 – Thermal plasticity and pace-of-life acceleration inside viviparous populations<\/strong><\/p>\n\n\n\n

This activity aims at testing if an average increase in ambient temperatures leads to a reduction in generation time associated with faster growth and sexual maturation, greater early life reproductive effort, but reduced longevity and accelerated senescence. Here, we will investigate comprehensively warming effects on life history strategies using long-term field data of viviparous populations in the Massif Central region with two complementary data sets. We will combine these analyses with an exceptional common garden experiment in the Terrestrial Metatron designed to test the causal relationship between summer warming and early life history across the geographic range.<\/p>\n\n\n\n

WP3 – Thermal plasticity and pace-of-life acceleration inside oviparous populations<\/strong><\/p>\n\n\n\n

We hypothesize that populations with an oviparous reproductive mode are located on a faster line of the life history continuum than viviparous populations. To test this, we will extend our comparative analysis to oviparous populations from Southwestern France. Our preliminary investigations identified sites spreading from sea level to the mountain range of the Pyrenees, where common lizards face a wide diversity of climates and occupy a range of habitats. The possibility to reproduce our analysis of pace-of-life acceleration in closely related oviparous populations will open a window to understanding this key evolutionary innovation and its ecological consequences<\/p>\n\n\n\n

WP4 – Increased risks of tipping points and population decline<\/strong><\/p>\n\n\n\n

This activity is aimed at testing causal environmental factors and sensitive life stages during which warmer conditions increase the risks of reaching critical physiological tipping points. In earlier studies with viviparous common lizards, we found decreased body condition maintenance below critical temperatures due to the interaction of multiple stressors such as high nighttime temperatures, limited food intake and water deprivation. Cross-sectional surveys of viviparous populations further indicate that high nighttime temperatures during the summer time are more predictive of pace-of-life acceleration than high daytime temperature. Here, we will test these hypotheses and refine proximate mechanisms involved in pace-of-life acceleration using 3 sets of controlled laboratory experiments with wild lizards from both reproductive modes. <\/p>\n\n\n\n

WP5 – Physiological assays of oxidative stress and telomere biology<\/strong><\/p>\n\n\n\n

To clarify the proximate physiological mechanisms involved in pace-of-life acceleration, we will focus on non-energetic trade-offs between production and maintenance (oxidative stress including DNA damage and telomere biology), since this trade-off is a central one involved in the regulation of the pace-of-life. We will conduct a number of biological assays in lizards from WP2, WP3 and WP4, where we will (i) measure TL using a qPCR method, (ii) quantify blood oxidative balance including reactive oxygen species (ROS, mostly organic hydroperoxides) and antioxidant capacity (total antioxidant barrier), and (iii) measure DNA oxidative damages and repair mechanisms.<\/p>\n\n\n\n\n\n\n\n

Partnership<\/h2>\n\n\n\n
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The CEREEP-Ecotron IleDeFrance center will coordinate project, lead WP1 and participate in all tasks of the project. Individual participants at CEREEP-Ecotron IleDeFrance are:<\/p>\n\n\n\n