Tracking the Mighty Sabertooths

This is a modern Tiger print.
By Aiwok, via Wikipedia.

Did you hear about those newly-discovered saber-toothed cat footprints? If not, check it out over at Science (there’s an awesome picture). The tracks are apparently up to 19cm across – bigger than a Bengal tiger’s! They were discovered in Argentina (because some countries have all the luck these days), and presented at a conference in May. These tracks probably belonged to a species of Smilodon, the most famous saber-toothed cats of them all.

Sabertooth tracks are rare, but these aren’t the first. I’ll get more into that later, but first: what exactly is a saber-toothed cat? Are they really cats anyway? 

Island of the Tiny People

In 2003, the field of human evolution was rocked by the discovery of “hobbits,” an ancient species of human relatives who stood barely more than a meter tall. Named Homo floresiensis, they lived on the Indonesian island of Flores, and for years researchers argued over whether they represented the first-known human case of “island dwarfism” or if these ancient individuals had some sort of disease causing their short stature. If they were diseased, what disease did they have? If they were a legitimate species, where did they come from?

The disease hypothesis has mostly fallen out of favor. Numerous studies have countered suggestions that H. floresiensis had microcephaly or hypothyroidism or other proposed conditions. On Wednesday, a new study provided evidence against Down Syndrome being responsible for the fossils’ appearance. So it seems the “hobbits” were their own species, but that leaves still many questions.

The Earth's Deepest Scars

No matter how thoroughly researched and well-understood a scientific theory is, there’s always room for improvement, always something we missed. Plate tectonics is one of the most powerful and comprehensive theories in modern science, but according to a new study out today, we may have missed an important piece of the geologic puzzle. According to this research, tectonic activity may be controlled by forces deeper below the surface than we’ve realized.

Plate tectonics theory explains how the Earth’s crust moves and changes. The crust isn’t a solid shell over the Earth, it’s broken into fragments: plates. Each plate butts right up against all the surrounding plates, so there’s no space in between, but they can rotate in place, or shift like conveyor belts, sliding and grinding past each other, into each other, or underneath each other. Boundaries between plates are areas of massive geologic activity. Where plates move together, they form massive mountains or deep trenches; where plates pull apart, volcanic activity creates new crust. The surface of the Earth is constantly shaking, shifting, and deforming, mostly at these boundaries.

This is a map of the major tectonic plates of the Earth.
Notice the places where the plates meet - those are the very active plate boundaries.
Image from Wikipedia.

"Saurian" is Already the Best Dinosaur Video Game of All Time

As popular as dinosaurs are, they’ve been surprisingly under-developed in video games. Most “dinosaur video games” – Primal Carnage, Turok, ARK, etc. – fun as they may be, feature re-hashed versions of misinformed prehistoric beasts being hunted and/or fought and/or ridden by humans. And just as the same-y anachronistic lizard-monsters of Jurassic World didn’t cut it for a lot of dino-fans, the ancient beasts of those video games similarly fail to impress. They just don’t feel like real dinosaurs.

And then there's Saurian. Watch this video:

Dinosaurs don't get realer than that.

The Thunder Birds and the Bees

Every Spring in the nature preserve where I currently work, we are treated to the sight of a dozen or so tiny fluffy Canadian goslings. Everywhere they go, they are accompanied by both parents, who watch over them cautiously and confidently. Getting too close will earn you a display of head-bobbing and a stern hiss from mom or dad. The reproductive behavior of these birds is one of their most fascinating and endearing qualities.

Reproductive behavior is notoriously difficult to glean from fossils, which is a shame given how important sexual traits are in living creatures. How did ancient species select mates? Did they mate for life? Who watched the nest? All of these and more questions often go unanswered. But sometimes we get just the right data, as in the case of a new study on an ancient bird called a mihirung.

Human Environmental Engineering Goes Back a Long, Long Time

An alien species visiting Earth would find a planet clearly dominated by one species. It’s no secret that humanity has a major influence on all aspects of Earth processes – we’ve covered major portions of land surface in stone and asphalt; we’ve cleared natural landscapes and driven an ever-increasing number of species to extinction; we’ve filled the oceans with plastic and the atmosphere with greenhouse gases. This planet is very firmly in the grip of human activity.

But this legacy of environmental modification goes back further than we generally appreciate. Today’s issue of PNAS has a special section devoted to human evolution, and one paper outlines the modern understanding of the many ways our species has affected the physical world around us, and just how long we’ve been doing it. The fact is that our modern explorers – the intrepid adventurers of the past few centuries who discovered lands populated only by indigenous peoples or long-gone civilizations – were alien visitors to parts of the planet already dramatically transformed by human influence.

Here are some of the ways our species has been shaping natural environments since long before written history:

The Mystery of the Sunken City of Zakynthos

This scientific discovery reads like a science-fiction mystery novel.

It starts in 2014, when a group of tourists visiting the Greek island of Zakynthos decided to go snorkeling. While exploring the shallow ocean waters close to Alikanas Bay they stumbled upon what appeared to be the remnants of a sunken civilization: flat pavement stones and the circular bases of collapsed colonnades. Perhaps these were lost fragments of a city port submerged by the sea?

The divers took pictures and uploaded them online, where they reached the attention of Greece’s Ephorate of Underwater Antiquities, who sent in an archaeological investigation team. The team discovered something very odd: there was no pottery, no coins, no signs at all of any human life. If this had once been a city, who lived there? Who built it? And why didn’t they leave behind any artifacts?

Ghost World - Part III: Resurrection

De-extinction. It's an amazing and controversial idea, and it may even be impossible. It's also not what you think. 

In Part I of this series, I reviewed the ways in which our world is a poor impersonation of what it was thousands of years ago, haunted by the absence of the ancient giants that once provided stability to ecosystems. In Part II, I reviewed the ways in which modern researchers are hoping to fix those ecosystems, by transporting "replacement" species to fill the gaps left by extinction, and even "un-domesticate" certain species to recreate their wild ancestors. 

Isn't there another option though? Instead of trying to replace the dead, why not bring them back? Why not simply clone extinct species?