The Peculiar Dispatch #006

Africa is changing beneath our feet. Scientists have found new evidence that a vast plume of extremely hot rock rising from deep within Earth's mantle is helping drive movement along the East African Rift, the enormous geological fracture where part of the continent is gradually pulling away from the rest.

The rift stretches for thousands of kilometres through eastern Africa. Over geological timescales, the Somali Plate is moving away from the rest of the African Plate. Eventually, we're talking millions of years, not something happening next Tuesday. Also, continued rifting could allow ocean water to flood into parts of the region.

The result could ultimately be extraordinary. Africa's geography could be fundamentally redrawn, with a new ocean basin separating part of eastern Africa from the rest of the continent.

The new research helps explain why this enormous process is occurring. The forces aren't simply coming from the crust. The material rising from much deeper inside Earth appears to be playing a role too.

In other words, we're living on a planet whose continents are still very much under construction.

The Atacama Desert in Chile is famous for being brutally dry. Parts of it receive so little precipitation that the landscape is regularly used as an analogue for Mars.

And then It snowed.

Rare storms recently swept across northern Chile, blanketing huge areas of the normally bone-dry desert in white. Other parts experienced extraordinary rainfall, producing flooding and mudflows.

The weather was significant enough to interfere with astronomical observatories operating in the region. The Atacama's extreme dryness is one reason some of the world's most sophisticated telescopes are located there. Clear skies, extremely low humidity and high elevations make it exceptional for astronomy.

Now satellite images have captured this famously Mars-like landscape looking more like Antarctica.

One footprint, 55 million years old.

Researchers studying a fossilised footprint from King George Island have identified what they believe to be evidence of a predatory mammal walking across Antarctica during the Eocene. That's remarkable because today's Antarctica couldn't look much less welcoming to terrestrial mammals, but 55 million years ago, Earth was much warmer.

Antarctica supported forests and ecosystems inhabited by animals completely unlike the penguin-dominated environment we associate with the continent today. The print was preserved in ancient volcanic mud and represents the earliest evidence of a carnivorous mammal yet reported from Antarctica. It's one of those fossils that captures something beautifully simple:

An animal walked through some mud 55 million years ago, the mud hardened, Antarctica froze and somehow...

its footprint survived.

The thylacine already looked as though evolution couldn't decide what it wanted to build. A striped, dog-like animal... that was actually a marsupial.

Now researchers have reconstructed its skull in unprecedented detail and concluded that its hunting mechanics may have been unlike those of any living predator. The research suggests the thylacine wasn't simply the marsupial equivalent of a wolf. Its skull combined characteristics in a way that has no close modern analogue. That matters because photographs make thylacines look deceptively familiar.

They resemble dogs.

But underneath that familiar exterior was an animal separated from dogs and wolves by an enormous evolutionary distance. The last known captive thylacine died in 1936. So we're now trying to reconstruct the behaviour of an animal humans watched disappear less than a century ago, using the anatomy it left behind.

A) Earth
B) Venus
C) Mars
D) Jupiter

C — Mars.

Olympus Mons is an absolutely enormous shield volcano.

It rises roughly 21–22 kilometres above the surrounding terrain and spans hundreds of kilometres.

For comparison, Mount Everest's summit sits 8.85 km above sea level.

Olympus Mons is so broad that if you stood on parts of its slope, the curvature of Mars could prevent you from seeing the volcano's summit.

A) Blue whale
B) Howler monkey
C) Sperm whale
D) African elephant

C — Sperm whale.

Sperm whales produce extraordinarily powerful clicks as part of their echolocation system.

Their clicks have been measured at source levels above 230 decibels underwater, making them among the most intense biological sounds known.

They use these extraordinary pulses to investigate their surroundings and hunt in the dark depths of the ocean.

Which is useful when your dinner might be a squid hundreds or thousands of metres below the surface.

A) Chimpanzee
B) Koala
C) Panda
D) Raccoon

B — Koala.

Despite being marsupials whose lineage is vastly removed from ours, koalas independently evolved fingerprints with ridges and patterns remarkably similar to human fingerprints.

Under magnification, the similarities can be striking.

Even better:

Their fingerprints are thought to have evolved independently rather than being inherited from a recent common fingerprinted ancestor.

So evolution essentially arrived at a similar solution twice.

Smash the week!