Peter Girguis - How microbes define life on Earth

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Peter Girguis, Professor of Organismic and Evolutionary Biology at Harvard University, examines microbes, life and its origins.

About Peter Girguis

"I’m a Professor of Organismic and Evolutionary Biology at Harvard University.

My research focuses on the deep sea and the relationship that animals and microbes have to one another, but also to their environment. We do a lot of work developing new tools to make measurements that we couldn’t make before. I do so with an eye towards democratising science, with a hope that all have an opportunity to study the deep ocean."

Key Points

• Microbes harness energy in ways animals can’t; life exists and Earth is habitable thanks to their ability to create oxygen, nitrogen and the conditions that animals need to survive.
• Scientists gain insights to life’s origins by observing life now and making deductions, but they have to be careful not to project today’s conditions onto the past.
• Microbiology may help us understand the relationship between the living and the non-living worlds.

When we think about life on Earth, we often immediately think of the organisms we’re familiar with, including us. What does it mean to be alive on Earth? Well, it’s humans, cats, dogs or birds – things that we have experiences with every day. Really, the diversity of life on Earth is in so many ways mind-blowing. There are animals that live such different lifestyles from us. Some of the fish that live in the deep ocean, for example, never see the light of day. In fact, they never touch a surface. They’re floating in the mid-water their entire lives, they have organs that allow them to make their own light. But even more extreme are microbes. Microbes are capable of doing things that we cannot possibly ever pull off as an animal.