The most extreme life on Earth part three: the great deep sea farmers

In the abyss of the deep, vents provide energy for an oasis of incredible and bizarre life.

The bottom of our oceans are a black expanse of nothingness for hundreds of kilometers in each direction. Yet in the darkness of the deep sea desert, hydrothermal vents provide a spectacular oasis, as densely populated as most ecosystems on land, boasting an array of the strangest animals on the planet.

In the deep abyss, you have to deal with crushingly high pressures, low and high temperatures but most of all, an absence of energy. About a kilometre down there is no light and without photosynthesis, or basically anything else, finding an energy source is like finding a needle in a haystack.

The vents provide energy by constantly pumping superheated water (up to 400oC, as at high pressures the boiling point of water increases), which have previously gathered minerals in the rock below.

Large animals can’t use this chemical energy directly, but incredibly they literally farm microbes which can.

Tube worms (above and below) can grow to a massive 3 meters long, and they are gross. Perhaps the weirdest thing about them isn’t the fact that they look like a garden worm on steroids, but that they don’t have an anus. Instead, they gather their excrement in a sac, which slowly fills up and poisons them until they die. More remarkable still, their farming of microbes has gone so far that they have replaced their digestive tract with their livestock. Infact, half of the body weight of a tube worm is pure microbes, constantly using the hydrogen sulphide to provide the worm with energy.

The tube worm outside its shell showing the sac which slowly fills up with its own excrement.

Pompeii worms are equally as bizarre, but farm their microbes in a more traditional sense (kind of). They harbour the livestock on their back, let them grow and then let other worms feed on them. Vent shrimps do something similar, growing microbes on their body, but instead of letting others harvest them, they wait until they shed their skin, and then eat their old carcass.

A Pompeii worm

Considering these crazy creatures have been farming for millions of years, and we only started 12,000 years ago, maybe they’ve beaten us other things? If we look further maybe they’ve got little cars and record players, and are studying humans in tiny, deep sea laboratories.

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What happens when social and climate extremes collide?

Hundreds of thousands of people have died in the Syrian civil war, but would this have been prevented without climate change?

For most of us, the image of climate change is a hungry polar bear in a distant land, orangutans without a home or the bleaching of our precious coral reefs. For others, it means war.

Collin Kelley from Imperial College London explains that the appalling suffering from the Syrian civil war, whilst facilitated by extreme governance, is in fact the result of climate change. Collin explains that between 2007 and 2010 the fertile crescent, on which Syria lies, experienced the worst drought ever recorded. Although gross mismanagement by Syria’s president crippled their water supply, this was a drought that would be impossible without the release of greenhouse gases from humans.

The drought that lasted for 3 years resulted in crop and livestock devastation, but would not have been possible without rising greenhouse gas emissions.

The drought caused catastrophic loss of livestock and cropland, and without food a whopping 1.5 million people moved from rural areas to the cities, just to try and survive. Combine this with a huge influx of Iraqi refugees and Syrian cities faced massive overpopulation, crime, illegal settlement and famine. The Al-Assad regime has since systematically neglected the migrants, stimulating the shocking civil war.

This story makes two things abundantly clear:

Climate extremes, which are becoming more frequent, colliding with unstable societies ends in disaster.

Climate change isn’t just for tree huggers and weed smokers, but for anyone who cares about society and everyone in it.


The most extreme life on the planet part two: living for 250 million years.

Could a microbe (arrow) live inside a salt crystal for 250million years?

On the turn of the millennia, Russell Vreeland released an incredibly controversial paper, in which he claimed they had found a microbe that had been alive for 250 million years. That’s your life, 30000000 times. More remarkable still, the microbe had survived inside a salt crystal (above).

Originally, it was received with a great deal of caution in the scientific community, as no-one thought life could persist that long, even if in suspended animation, let alone active and growing. After all, how do you get energy to grow for a quarter of a billion years?

Since then, another scientist, Brian Schubert, devised a more robust experiment, suggesting that microbes can live off the glycerol produced by just one cell of green algae for 12.5 million years. The glycerol would provide energy for cell repair whilst preventing dehydration and protein damage.

It is not beyond the realms of possibility then, that life could persist for 250 million years, or even longer. Could Vreeland have been right all along? In a booming scientific field, the race is on to find out.

Extreme life part one: volcanoes:https://swiftscience971095579.wordpress.com/2019/04/21/the-most-extreme-life-on-the-planet-part-one-life-in-volcanos/‎(opens in a new tab)

To understand how long 250 million years read: Feel old yet? Understanding just how ancient Earth is: https://swiftscience971095579.wordpress.com/2019/04/10/feel-old-yet-understanding-just-how-ancient-earth-is/‎(opens in a new tab)

The most extreme life on the planet. Part one: life in volcanos.

Yellowstone National Park, with each ring of colour due to a different microorganism.

For all its beauty, Yellowstone National Park is a terrifying place. If it erupted tomorrow, most of America would be drowned in ash, and they wouldn’t see sunlight for weeks. Add extreme pressures, no nutrients and oxygen depletion to the searing heat in volcanic pools and you can understand why we used to think life here was impossible.

However, those amazing dashes of red, green and yellows sweeping across the volcanic pools are not from the rocks but from microbial life which aren’t just tolerating the scorching heat, but need it to survive.

Apart from being a liiitle bit painful, if I jumped in the pool and tried to survive, my cell membranes would crumble, my enzymes and proteins would melt and my DNA simply unravel and fall apart. How is it then, that at 115°C we still find archaea (single celled organisms which are as different from bacteria as we are)?

To survive and grow, these archaea have ultra strong membranes to stop the cell from melting. Weirdly, they then pump salt into their cells, acting as a clamp to hold the protein and DNA structures together, so they don’t fragment. For food the ingenious and complicatedly named Sulfolobus acidocaldarius actually sticks and clings onto sulphur crystals and uses the hydrogen sulphide to gather energy.

Nothing so far has been found above 120°C as it is thought any large molecules will simply fall apart. But, we have been wrong before.

As an aside to why you should care, the first ever life, which has given rise to you, me and everything living almost definitely lived in a deep sea volcano. Furthermore, the enzyme used to replicate DNA and sequence entire genomes was isolated from a bacteria living in a volcano.

If you are interested, I will be writing about various extreme life in the near future, including life in space, other planets, inside ice, rocks and salt and will be asking whether it is possible for an organism to live for 250 million years.