Discovering Fossilized Microbes in Antarctic Ice Cores With Manuel Martinez Garcia

Manuel Martinez Garcia, Ph.D., a professor of microbiology in the Physiology, Genetics and Microbiology Department at the University of Alicante in Spain, paints a picture of what microbial life looked like thousands of years ago by analyzing microbial genomic signatures within ice cores collected from the Antarctic ice shelves in the 1990s. 

Links for the Episode 

• New avenues for potentially seeking microbial responses to climate change beneath Antarctic ice shelves – mSphere paper. 
• Viruses under the Antarctic Ice Shelf are active and potentially involved in global nutrient cycles – Nature communications article. 
• Manuel Martinez Garcia's Lab website. 
• How stable is the West Antarctic Ice Shelf? – Press Release from Alfred Wegener Institute.
• Take the MTM listener survey!
• Watch this episode: https://youtu.be/CHCMO74_gIY

Ashley's Biggest Takeaways

• There is a unique habitat beneath Antarctic ice shelves, where microbes live without light and rely on unusual energy sources. 
• Ice cores from these Antarctic ice shelves can preserve fossilized genomic records of microbial life from long ago. 
• Comparing past and present samples can help us understand how microbial life is responding to environmental stressors, like temperature changes and acidification, over time.
• It can also provide key insights to changes in biodiversity.

Featured Quotes: 

Motivation for the Research

Ice shelves are like massive floating ice that are in Antarctica, mainly. They can be as big as, for example, France, the country. So, they are super big—they are enormous. And they can be as thick as, let's say, 1000 meters. So, this is a massive [piece of] ice that we have in our planet.

And beneath that massive ice, we can have a very peculiar and a special habitat in which microbes live without light. They have to manage, to thrive and reproduce, without using a standard energy like we have on the surface of the sea or in the forest, where we have light that is driving and providing the energy for the ecosystem. But in this case, these ecosystems are totally different. 

[The ice shelves] are deep and interconnected. Basically, there are different oceanic currents, for example, there is one Circumpolar Current that surrounds Antarctica, and there are also other currents that basically go from the bottom to the surface, moving, you know, all the water masses. 

The interesting part of this story is that every single second in our lives, this sea that is beneath the platform, the ice shelf, is frozen over and over, and then we have different layers of antiquity that preserve the microbes that are living in the oce