These articles explore evolution - the changes seen in the inherited traits of a population from one generation to the next. Evolution is one of the great mysteries of biology, since it is a slow process and difficult to study.

Hint: It wasn't because an enormous comet or asteroid struck Earth.

If dinosaurs hadn't gone extinct, you wouldn't exist. Extinction may seem inherently bad, but sometimes the death of a species encourages new life.

We're used to taking the phrase "survival of the fittest" to mean it's an "every man for himself" world. But some animals (like worker bees) sacrifice themselves to ensure their species lives on. Why would they do this?

Evolution is a never-ending process, but some scientists believe it might be speeding up as human activity impacts the environment.

Our planet has been through five mass extinctions, and some experts say we're heading into our sixth. What can we learn from the past events — and the animals that survived — to make sure we humans can stick around?

Humans can certainly claim some of these, but sloths, giraffes and pandas wanted a piece of the action, too. The hyena adaptation, however, may just blow your mind.

Undoubtedly, the concept of privacy has evolved for humans. We're increasingly willing to share our passionate love of needlepoint with our neighbors and also blog about it to strangers. Is there a biological reason for all that sharing?

Comic books and pulps rot our brains, television is a vast wasteland and the Internet scatters our senses. Has the heyday of human intelligence passed?

How did life on Earth begin? Theories abound, but one popular one posits that it started spontaneously from primordial ooze on our planet, while another holds that it literally came from outer space. Who's right?

Where did humans come from? How did they migrate throughout the globe? Thanks to a longstanding anthropological concept and an unexpected discovery, conventional wisdom on human migration may be irrevocably shattered.

When peering thousands of years into the future, there are certain things we can count on -- evolution, extinction, plate tectonics, climate change and, quite possibly, the eruption of a supervolcano. What else does the Earth's far future hold?

Once hunted to the brink of extinction, bearded vultures now lack the genetic diversity to evolve effectively through natural selection or genetic drift. Is the bird's small gene pool the death knell for the species?

As the human population soars, our ability to feed all those hungry mouths can't keep pace. How did an English economist by the name of Thomas Malthus wind up thinking about this very issue in the 19th century, and what's his connection to Darwin?

Every species on Earth, from the majestic humpback whale to the bacteria happily living in your gut, has a special role to play within a defined ecosystem. Can organisms ever trade their existing niches for new ones?

Maybe you've noticed that a lot of unrelated marine animals have a torpedo-like body -- a dolphin may not be related to a small fish, but the shape of both species gets each one through the water quickly. On the other hand, two similar species can evolve into entirely different species. So what's going on here: convergent or divergent evolution?

Extinction can come in the form of an asteroid strike, a volcano eruption or even a nearby supernova. But sometimes devastation follows a chain of tiny, almost imperceptible changes. Who (or what) is behind what some scientists call the sixth mass extinction?

A society run by women doesn't have to be the mirror opposite of one run by men. What does a matriarchy look like, and is it possible you're already living in one?

Let's assume that long ago Homo sapiens communicated by grunting at one another. How and when did all those grunting sounds evolve into a verb tenses, clauses and proper nouns?

Long before sonnets, sestinas and short stories were historical accounts of kings carved onto clay tablets. Who were the first writers and what did they scribble?

Our planet sits in the sun’s Goldilocks zone: the region that’s not too hot and not too cold. But it takes more than temperature to make a planet just right for supporting forms of life as diverse as the Earth’s.

The day our human ancestors figured out fire must have been a pretty exciting one. Through the years, we've changed in so many ways, from growing bigger brains to burying our dead. But how did we get from there to here?

Since Charles Darwin published the theory of evolution by means of natural selection, myths and misinterpretations have eroded public understanding of his ideas. Ready to take another look at one of the related questions that just won't die?

Thanks to our big brains, we humans have figured out ways to make food easily accessible (all 24 hours of the day). But in this era of obesity, can we pinpoint the very beginnings of when we started packing on the pounds -- and is it further back in time than the rise of fast food?

Many of us don't have a clue as to what our great-great grandmother's name was. (No offense, great-great grandmas everywhere.) So imagine extending that family tree a few million years beyond that and seeing what our ancestors were up to.

As guardians of the planet, we have our work cut out for us, especially if we hope to keep the Earth's biodiversity remotely intact. Which species could soon vanish forever?