The first skeletons evolved repeatedly in chalky seas

The first skeletons evolved multiple times independently because of unusually chalky seas, later becoming essential for survival even when chalk became scarce.

Calcium-based skeletons appeared suddenly in the fossil record around 550 million years ago, fundamentally changing the global carbon cycle and introducing a wealth of new predatory strategies to the sea.

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The Science of Snow

One of the best things about this time of year is that faint possibility that it might snow. The promise of snowmen and snowball fights, of time of work and school, of that cheer that only snow can bring, is almost enough to get us through the long, dark, bleak winter. They say no two snowflakes are alike, and although some pesky scientists have proved that incorrect, the intricate crystalline structure of snowflakes is truly beautiful. Snow is also hugely important for wildlife and people, and plays an important part in keeping our climate stable. To say Merry Christmas from Curious Meerkat this year, here’s a look at the science of snow – from its formation to its recreational uses and its role in the healthy functioning of Planet Earth.

Snow is simply a form of frozen rain, or precipitation, which occurs when cloud temperature is at or below freezing. Snow crystals tend to form in heavy, moisture-rich clouds, containing dust particles. Ice crystals form around these dust particles, called ice nuclei as the water vapour in the cloud slowly condenses. Snowflakes can be formed from multiple crystals that have melted slightly and fused together, or through new water vapour condensing onto existing crystals. As ice crystals grow inside the cloud, they get heavier and heavier until eventually their weight causes them to fall from the cloud. If the air temperature at the ground is low enough (below about 2°C), these crystals will remain frozen all the way and land on the ground as snow. Often, snow flakes that form in the clouds will have melted by the time they reach Earth, and all we see is the rain that results.

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The Effect of Wildfires on Climate and Health

Humans burn plant matter for many reasons; clearing forests for agricultural land, slash-and-burn agriculture, ritual savannah burning, wildfires. Recent research by Professor Mark Jacobson at Standford University suggests that burning living matter may contribute far more to climate change than previously thought. This is because, unlike other types of emissions, burning plant matter releases carbon particles into the atmosphere which accelerate warming. These particles are also very damaging to human health, and are responsible for the deaths of 250,000 people every year.

Each year, humans pump nearly 40 billion tons of carbon dioxide into the atmosphere. We are now certain that these emissions, along with other greenhouse gases, are altering our climate and warming the planet. One major source of carbon dioxide emissions is burning plant matter, either deliberately or because of wildfires. But the contribution of fires to climate change has not previously been quantified.

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The Ants Who Store Our Carbon

As we are very rapidly discovering, living creatures have the ability to drastically alter the climate and weather systems on Earth, and the greatest changes are achieved by the species that are greatest in number. Ants may be no exception to this rule, and recent geological research suggests that ants may be providing a vital counter-balance to our CO2 emitting ways. Ants may be cooling the climate as we warm it. But are ants the solution to climate change?

Ants and Climate Change

A recent study published in Geology has begun to reveal the role ants play in keeping Earth’s atmosphere cool. They might be small, but ants are ubiquitous on Earth, found on every continent except Antarctica and numbering over 15,000 species. They have the potential to have a big impact. The study published this month showed that ants collect minerals from their environment and change them into rock, inadvertently trapping carbon dioxide gas in the rock as they do so. This process is identical to the way in which atmospheric CO2 is sequestered by the oceans, and naturally weathered on land.

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