Will Dunham

Dogs today come in a mind-blowing array of shapes and sizes, from the diminutive pug, Pekingese and Pomeranian to the grand Irish Wolfhound, Great Dane and Saint Bernard. But when did this diversity in canine forms begin? New research shows it dates back many millennia, long before modern breeding practices.

About 23 million years ago, a species of rhinoceros - similar in size to the modern Indian rhino but lacking a horn - made its home in the challenging environment of the Canadian High Arctic, which at the time was warmer than it is now but still experienced snow and months of wintertime darkness.

Lockhart portrayed the archetypal TV mom of the 1950s and 1960s.

Scientists may be coming closer to confirming the existence of dark matter - the invisible stuff thought to make up more than a quarter of the cosmos - as they study a diffuse glow of gamma rays near the center of our galaxy.

The fossil of a small reptile that inhabited Scotland during the age of dinosaurs 167 million years ago has scientists puzzled. It mixed snake-like traits and lizard-like traits. So was it an early ancestor of snakes or perhaps just an evolutionary oddball? Whatever the answer, it was a formidable little beast.

About 12,000 years ago, hunter-gatherers who inhabited a swathe of Arabian desert carved life-sized images of camels and other animals on sandstone cliffs and boulders, using rock art to mark the location of water sources in an illustration of how ancient people tackled some of Earth's most inhospitable environs.

In 1990, an ancient human skull was unearthed in China's Hubei Province that was so badly deformed during fossilization that it was hard to gauge its significance. A new analysis now indicates that the skull belongs to an early branch of a sister lineage to our species in a finding that may shake up the understanding of how human evolution unfolded over the past million years or so.

Ripe fruit is an integral part of the diet of wild chimpanzees, as they routinely eat an amount equaling about 10% of their body weight daily. And because this fruit often is undergoing natural fermentation, they are ingesting a surprising quantity of alcohol - the equivalent, according to scientists, of a person drinking two cocktails per day.

Amber found in the Amazon forest region of Ecuador containing a trove of well-preserved fossils of wasps, midges, flies, beetles and other insects is giving a glimpse of a Cretaceous Period ecosystem in South America crawling with activity 112 million years ago during the age of dinosaurs.

The agency, called Build Canada Homes, will construct affordable housing for low-income households and work with private developers to build homes aimed at the middle class.