by Carol A Westbrook

This is the story of a DNA mutation that profoundly changed the course of human history, and had a major impact on human activities, altering communication, transportation, agriculture, and warfare. This story is about the horse, and how came to be a domesticated, rideable animal due to this DNA mutation. This genetic change in the horse occurred unexpectedly late, about 4500 years ago, which is almost 5000 years later than the domestication of pigs, cattle, goats and sheep.
The earliest ancestors of horses, known as Eohippus, first appeared in North America about 55 million years ago, where they evolved into Equus, the modern horse ,by the time of the Pleistocene epoch. They spread from North America to Asia and Europe by crossing the Bering land bridge at a time when the oceans were much lower than they are today, that is during the last ice age. As Eohippus evolved into the horse as we know it today, it continued to be an important source of meat for the humans, and was hunted throughout the Pleistocene epoch (ice age).

The North American horse went extinct at the end of the Pleistocene epoch, about 10,000 years ago, along with most of North America’s large mammals. This period of extinction is known as the Pleistocene megafauna extinction event, and resulted in the loss of mammoths, mastodons saber-toothed cats, dire wolves, giant ground sloths and giant beavers. The cause of the extinction included climate change—the earth warmed up—over-hunting, change in flora resulting from climate change and the appearance of bison which competed directly with horses for food.
The horse disappeared from North America, but survived in Europe and Asia, particularly the Eurasian Steppes. Read more »

To be alive is to maintain a coherent structure in a variable environment. Entropy favors the dispersal of energy, like heat diffusing into the surroundings. Cells, like fridges, resist this drift only by expending energy. At the base of the food chain, energy is harvested from the sun; at the next layer, it is consumed and transferred, and so begins the game of predation. Yet predation need not always be aggressive or zero-sum. Mutualistic interactions abound. Species collaborate when it conserves energy. For example, whistling-thorn trees in Kenya trade food and shelter to ants for protection. Ants patrol the tree, fending off herbivores from insects to elephants. When an organism cannot provide a resource or service without risking its own survival, opportunities for cooperative exchange are limited. Beyond the cooperative, predation emerges in its more familiar, competitive form. At every level, the imperative is the same: accumulate enough energy to maintain and reproduce. How this energy is obtained, conserved, or defended produces the rich diversity of strategies observed in nature.



We humans think we’re so smart. But a
Giant Tarantulas 

by Steve Szilagyi
Jaffer Kolb. Lake Mývatn, October 13th, 12:08 am.





A recent news story about the fate of Ernest Shackleton’s ship 

