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Genomic erosion and biodiversity conservation

This month's ERGA BioGenome Analysis & Applications Seminar will feature three short talks on the topic of genomic erosion and biodiversity conservation. Learn more below about the featured talks and speakers: Hernán E. Morales, Samuel Speak, and Xuejing Wang.


🕚 Tuesday, April 29th 2025 - 11:00 AM CEST



Genomic erosion and biodiversity conservation

The seminar will be divided in three parts (around 15 minutes each):


  1. Using genomes through time to study diversity loss - Hernán E. Morales

The biodiversity crisis is driving the loss of critical genomic diversity essential for species survival and adaptation. Even after population recovery, genetic diversity may continue to decline—a phenomenon known as "genetic drift debt." To investigate this, we compare whole genomes from pre-decline (100+ year-old museum specimens) and post-decline (modern) populations of endangered bird species with varied decline trajectories. We assess how population declines affect deleterious, functional, and neutral variation, and use simulations to evaluate how demographic history and conservation actions influence extinction risk and recovery. Our aim is to uncover the evolutionary dynamics of genomic erosion.


  1. Scoring deleterious alleles in endangered species – Samuel Speak

Captive breeding programmes can act as insurance populations against extinction and to preserve genetic diversity of endangered species. However, due to their small size, the survival of these populations is threatened by inbreeding depression resulting from high genetic load. We developed the LoadLift pipeline which utilises Combined Annotation-Dependent Depletion (CADD) scores from model species to estimate the genetic load within ultraconserved elements (UCEs) of individuals. Six pink pigeons (Nesoenas mayeri) were analysed with LoadLift and in silico crossings, to identify optimal mate pairings expected to show the least inbreeding depression. LoadLift was further used to assess the genetic load of the whooping crane (Grus americana), to compare the methods of LoadLift and SNPeff, showing good correspondence in their classifications of deleterious mutations. LoadLift aims to maximise the potential of ex situ populations for species conservation and restoration by enabling captive-breeding managers to reduce inbreeding depression and maintain long-term viable populations.


  1. Genomic erosion through the lens of comparative genomics – Xuejing Wang

The loss of genetic diversity and the species’ response can vary widely depending on their evolutionary histories, life-history traits and demographic trajectories. Comparative genomics offers a powerful framework to explore the dynamics of genomic erosion across species. We compared the genomes of three Mauritius birds with additional 36 birds spanning the avian phylogeny, to investigate the genomic consequences of their demographic collapses. We found that historical population sizes influenced current genetic health, with higher heterozygosity linked to greater heterozygous load and the ratio of effective to census population size predicted a species' conservation status. We also found significant differences in genetic load and genome structure between taxonomic groups, showing the value of multispecies comparisons.


Speakers


Hernán Morales studied Biology at UNAM, Mexico, and completed an MSc at the University of Groningen, Netherlands. He earned his PhD from Monash University, Australia, and joined the Globe Institute at the University of Copenhagen in 2019. In 2023, he established the Evolutionary and Conservation Genomics Group that utilizes (paleo)genomics, quantitative genomics, and evolutionary modelling methods to explore the mechanisms behind the generation, preservation, and loss of biodiversity.


Samuel Speak is a Postdoctoral Research Scientist in the Haerty Group at the Earlham Institute, working to identify loci associated with aquaculture relevant traits related to environmental stress within Tilapia species. Prior to this position, he was a NERC ARIES DTP PhD student at the University of East Anglia, the Natural History Museum London and Chester Zoo working on the conservation genomics of endangered bird species in zoos. During which he focused on quantifying the genetic load of individuals in captive breeding programs using CADD scores within the ultraconserved elements of the genomes. Applying this to threatened species including the pink pigeon (Nesoenas mayeri) and the whooping crane (Grus americana).


Xuejing Wang is a postdoc working in Evolutionary and Conservation Genomics Group in Globe Institute, University of Copenhagen. She currently works on the conservation genomics of Mauritius kestrel and other endangered birds, focusing on demographic history, temporal genetic dynamics and genetic load. During her PhD in University of Bern, she worked on the population genomics and evolution of an insular mammal, the Orkney vole.




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