Cells making dark oxygen and learning without a Brain

In photosynthesis, plants use carbon dioxide to make their own food and give out oxygen, which is used by all life forms on Earth. As we begin going underground, there are no there is no light, hence no plants and no photosynthesis. So, there mustn't be oxygen too. Right?

A study of underground environments in Canada found that at a depth of over 600 feet (200 m), oxygen levels are at a scale similar to photosynthesis occurring in the Amazonian rainforest. How can that be?

The provincial government of Alberta in Canada actively monitors the chemical composition and acidity of its aquifer water which is used for cattle farming and agriculture. A routine survey in 2015 found that deeper aquifers had greater oxygen concentrations and had larger number of living cells.

Using mass spectrometry, researchers confirmed that the oxygen wasn't geological in origin but biological. Sequencing of microbial samples in the area showed that methane-feeding bacteria created their own oxygen in the dark by breaking down nitrites (nitrogen and oxygen), which was then used to break down methane for energy.

This process is called dismutation and was thought to be rare but might be a way to support life deep underground writes Saugat Bolakhe in Quanta Magazine.

You can read about the science and its implications here.

Learning without a Brain

The brain is a crucial part of the learning process and keeps those memories locked in so that we do not repeat the same actions again in the future. Yet, a small jellyfish found in the Caribbean tells us otherwise.

Scientifically known as Tripedalia cystophora, the jellyfish is the size of a fingernail and does not have a brain. What it has is a sophisticated vision system consisting of four rhophalia - specialized visual sensory centers.

Each rhophalia has six eyes and around 1,000 neurons. So, the jellyfish has 4,000 neurons which is a miniscule number when compared to a fruitfly that has over 200,000.

Electrical signals generated from the rhophalia determine how the jellyfish moves. While other jellyfish can perceive light, T. cystophora also perceives contrast, meaning it can form images. In nature, these jellyfish can make out differences between tree roots and water and swerve to avoid the roots.

Researchers set up an experiment where they tricked the jellyfish into thinking that roots were located further away by changing the contrast. Initially, the jellyfish bumped into these new constructs but minutes after the experiments began, they were able to learn to avoid these structures and stopped bumping into them, writes Lina Zeldovich.

You can read the post here.

For those still in awe of their brains, here's a quick question.

What's the difference between coffee and caffeine and do they affect the brain the same way?

Some might be aware that caffeine is the psychoactive chemical that is present in coffee. So, can one just have caffeine and reap the same benefits?

To know more, read this post from Simran Dolwani on Coffee Table Science.

If you enjoyed reading this edition of the newsletter, do share it with at least two friends or colleagues.

Until next time,

Ameya

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