How long can ancient DNA survive, and how much stuff do we need to escape poverty?
Oct 5, 2023
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The podcast covers topics such as the impact of earthworms on agriculture, measuring the amount of resources needed to escape poverty, the outbreak of avian flu in the Galapagos Islands, preserving ancient DNA, and exploring deep time paleogenomics.
Studying ancient DNA can provide insights into the impact of glacial cycles on biodiversity over time.
Paleogenomics allows researchers to analyze DNA from different points in time, contributing to a better understanding of evolution and genetic interactions.
Deep dives
The Impact of Glacial Cycles on Biodiversity
The main process that has shaped biodiversity throughout much of the world is the glacial cycles. These ice ages, which started around 2.5 million years ago, have had a significant impact on biodiversity by causing species ranges to expand and contract. Studying deep time paleogenomes can help researchers understand how these glacial cycles have influenced biodiversity over time.
Unlocking Ancient Genes with Paleogenomics
Paleogenomics allows scientists to extract and decode fragments of DNA from ancient and extinct species. Advances in DNA sequencing technology and extraction methods have made it possible to study genomes from deep time periods, beyond 100,000 years. This capability provides researchers with a "time machine" to better understand evolution and biodiversity by directly analyzing DNA from different points in time.
Hybridization and Evolutionary Complexity
Analysis of ancient DNA has revealed that hybridization, or the interbreeding of different species, has played a significant role in evolutionary processes. Examples include the interbreeding between humans and Neanderthals, the presence of cave bear DNA in modern brown bears, and the identification of a hybrid mammoth species. These findings challenge the traditional view of evolution as a branching tree, highlighting the complexity of genetic interactions between different lineages.
Challenges and Future Directions for Paleogenomics
While paleogenomics has made significant strides, there are still challenges to overcome. Improvements in DNA extraction methods and bioinformatics are needed to optimize the analysis of highly degraded DNA fragments. These advancements will enhance the accessibility and usefulness of paleogenomic data, enabling further scientific discoveries in the field.
Next up on the show, as part of a special issue on ancient DNA, freelance producer Katherine Irving talks with Love Dalén, a professor of evolutionary genomics at the Centre for Palaeogenetics at Stockholm University. They talk about the longevity of ancient DNA and what it would take to let us see back even further. See the whole ancient DNA special issue here.
This week’s episode was produced with help from Podigy.