The genomic adaptations to cope with unpredictable climates over the course of life

Introduction

Increasing climatic fluctuations mean that animals need to evolve increased heat resilience whilst simultaneously coping with cold periods throughout their lives. Large animals are particularly susceptible to temperature fluctuations as their large size when mature exposes them to heat stress, and their small size when juvenile exposes them to cold stress.

Hypotheses

I will test two hypotheses that are central to understanding how large species evolve to cope with temperature fluctuations:

1. Genomic adaptations that increase heat resilience compromise cold resilience.
2. Genes that increase thermal resilience during early life have opposing effects on thermal resilience later in life.

Challenges in Research

Testing these hypotheses requires identifying the genomic basis of thermal resilience. This has remained elusive in large animals because of difficulties in:

1. Rearing high numbers of large animals.
2. Exposing them to natural temperature fluctuations.
3. Obtaining measurements of fitness-related traits such as growth of juveniles and reproduction of adults.

Methodology

I will solve these issues by studying the largest bird on Earth, the ostrich, monitored in large numbers under natural temperature conditions. This will allow me to take an interdisciplinary approach combining body temperature measurements and cutting-edge genotyping of 2000 juveniles and adults.

Collaboration and Data Utilization

A close partnership with a South African research station will enable me to utilize data on growth and reproduction of 11,700 juveniles and 1,800 adults exposed to the natural climate over 25 years.

Testing Local Adaptation

To test the importance of identified genes for local climatic adaptation, I will genotype natural populations of ostriches across climatic gradients.

Expected Outcomes

My work will resolve how genes conferring resilience to heat influence the ability to cope with cold, and if the same genes are important across different life stages. This will shape our understanding of thermal evolution in endothermic animals at a critical time.