MULTIFACETED DRIVERS OF PERFORMANCE VARIATION IN ANIMAL POPULATIONS: INVASIVE PREDATOR, RESOURCE AVAILABILITY AND HYBRIDIZATION
type: CreativeWork
description: The biodiversity on Earth is dramatically affected by global changes. To understand biodiversity loss and determine priorities for conservation, it is important to assess whether and how individuals can adapt to a continuous and drastic environmental change. Phenotypic variation is a key process that allow populations to withstand environmental changes by increasing survival and fitness, and can be related to both adaptations and phenotypic plasticity. For this reason, studies on phenotypic variation, and its associated fitness, analysing response to different stressors are needed. This thesis investigated phenotypic variability, through the study of performance variation, in response to three of the most pressing issue of global change: alien species, resource availability and hybridization. The first study (Chapter 2) focused on phenotypic variation of a native species in response to an alien predator. Italian agile frog embryos developed faster when exposed to the predator in laboratory condition and when collected in alien crayfish-invaded sites. This ontogenetic shift can be interpreted as a local adaptation to the alien predator and suggests that frogs are able to recognise the predatory risk. If these responses are effective, escape strategies against the invasive predator may improve the survival of frog populations. The second study (Chapter 3) analysed how sexually selected traits vary across different degree of resource availability. We assessed the existence of condition- and context-dependent sexual dimorphism (SD) within and among populations in the Italian wall lizard. Body condition and ecosystem productivity were the main drivers of body size SD variation, and body condition was also the main driver for head shape SD. The expression of SD in the Italian wall lizard is strictly related to the changes in resource availability. The third study (Chapter 4) evaluated how hybridization affects hybrid performance and the main drivers of performance differe…
abstract: The biodiversity on Earth is dramatically affected by global changes. To understand biodiversity loss and determine priorities for conservation, it is important to assess whether and how individuals can adapt to a continuous and drastic environmental change. Phenotypic variation is a key process that allow populations to withstand environmental changes by increasing survival and fitness, and can be related to both adaptations and phenotypic plasticity. For this reason, studies on phenotypic variation, and its associated fitness, analysing response to different stressors are needed. This thesis investigated phenotypic variability, through the study of performance variation, in response to three of the most pressing issue of global change: alien species, resource availability and hybridization. The first study (Chapter 2) focused on phenotypic variation of a native species in response to an alien predator. Italian agile frog embryos developed faster when exposed to the predator in laboratory condition and when collected in alien crayfish-invaded sites. This ontogenetic shift can be interpreted as a local adaptation to the alien predator and suggests that frogs are able to recognise the predatory risk. If these responses are effective, escape strategies against the invasive predator may improve the survival of frog populations. The second study (Chapter 3) analysed how sexually selected traits vary across different degree of resource availability. We assessed the existence of condition- and context-dependent sexual dimorphism (SD) within and among populations in the Italian wall lizard. Body condition and ecosystem productivity were the main drivers of body size SD variation, and body condition was also the main driver for head shape SD. The expression of SD in the Italian wall lizard is strictly related to the changes in resource availability. The third study (Chapter 4) evaluated how hybridization affects hybrid performance and the main drivers of performance differe…
author: MURARO, MARTINA
language: eng
keywords: invasive specie, adaptation, phenotypic plasticity, anti-predator strategie, hybridization, performance, environmental gradient, meta-analysi, sexual dimorphism, Settore BIO/05 - Zoologia, Settore BIO/07 - Ecologia
date published: 2023-05-02
date modified: 2026-07-27T20:19:05Z
provider: Università degli Studi di Milano
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Università degli Studi di Milano

PropertyValue
property ID: Handle
value: https://hdl.handle.net/2434/967499

PropertyValue
property ID: DOI
value: 10.13130/muraro-martina_phd2023-05-02