Monday 28 September 2009

Friday 25 September 2009

RADIALARIANS: TIMEKEEPERS OF ANCIENT SEAS

Radiolarian microfossils, tiny, siliceous, single-celled organisms, make for excellent timekeepers. Think of them as the world's smallest clocks. These wee fellows have been living in the world’s oceans for about 600 million years. Because they occur in continuous and well-dated sequences of rock, they act like a yardstick, helping geologists accurately date rock from around the globe.

Wednesday 23 September 2009

Monday 21 September 2009

MEGAFAUNA: EXTINCT GIANTS

Megafauna were part of a cohort of "giant" animals, species of large animals, reptiles, birds and mammals that went extinct during the Pleistocene as our rellies, the homeo sapien sapiens, were spreading out of Africa and southern Asia to populate the globe. Our rise marked the demise of many of the Earth's most interesting beasts. The term, 'megafauna' refers only to those species larger than forty-five kilograms. Many smaller animals who lived along side these giants also disappeared during the Pleistocene, but it is the largest of the lot who get the title and our attention.

While the fossil record shows that most of the megafauna from North and South America, northern Eurasia and Australia went extinct during this time, it is not the case for all large beasts. Blue Whales, hippopotamus and elephants are notable exceptions, surviving into modern times.

Were we to blame? The court is still out, but most scientists agree that we played a small role at least. Larger scale hunting, climate change, and spreading disease have all been fingered as the culprit for the loss, but, like most ancient mysteries, evidence is mixed and the truth is complicated. My vote is that their ultimate demise is a combination of the three.

Wednesday 16 September 2009

FIRST LIGHT: HAIDA GWAII

The enormous difference between high and low tide in Haida Gwaii – up to twenty three vertical feet – means that twice a day, vast swathes of shellfish are unveiled, free for the taking.

An ancient Haida saying is still often heard today, “When the tide is out, the table is set.”

Archaeological evidence shows that by about five thousand years ago, gathering shellfish replaced hunting and fishing as their primary food source. The shellfish meat was skewered on sticks, smoked and stored for use in winter or for travel.

Tuesday 15 September 2009

Sunday 6 September 2009

Friday 4 September 2009

Tuesday 1 September 2009