B. N. Horowitz, MD is a cardiologist and visiting professor at Harvard University's department of human evolutionary biology who turns to the natural world for insights into human well being.

There may be no one better to contemplate the meaning of cultural change than Kevin Kelly, whose life story reads like a treatise on the value and impacts of technology.

Michael Pollan is the author of "The Omnivore’s Dilemma", in which he explains how our food not only affects our health but has far-reaching political, economic and environmental implications.

Philosopher Dan Dennett calls for religion -- all religion -- to be taught in schools, so we can understand its nature as a natural phenomenon. Then he takes on The Purpose-Driven Life, disputing its claim that, to be moral, one must deny evolution.

Evolutionary ecologist Sara Lewis digs deep into firefly mating rituals to uncover a world of secret languages and strange gifts in these silent sparks.

(NOTE: Statements in this talk have been challenged by scientists working in this field. Read "Criticisms & updates" below for more details.) Elaine Morgan was a tenacious proponent of a theory that is not widely accepted. The aquatic ape hypothesis lays out the idea that humans evolved from primate ancestors who dwelt in watery habitats. He...

Nina Jablonski is author of Skin: A Natural History, a close look at human skin’s many remarkable traits: its colors, its sweatiness, the fact that we decorate it.

Congratulations! By being here, alive, you are one of history's winners -- the culmination of a success story four billion years in the making. The other 99 percent of species who have ever lived on earth are dead -- killed by fire, flood, asteroids, ice, heat and the cold math of natural selection. How did we get so lucky, and will we continue ...

Nearly 28,000 species of orchid grow all around the world, bearing every imaginable color, shape and pattern. There's a cunning purpose behind these elaborate displays: many orchids trick insects into pollinating, sometimes even into having sex with them. How do they deploy these deceptive tactics? Anne Gaskett dives into the surprisingly comple...

In this hilarious, whirlwind tour of the last four billion years of evolution, paleontologist and TED Fellow Lauren Sallan introduces us to some of the wildly diverse animals that roamed the prehistoric planet (from sharks with wings to galloping crocodiles and long-necked rhinos) and shows why paleontology is about way more than dinosaurs.

Dinosaurs once roamed the Earth. What were they like, why did they disappear, and what can we learn from them?

Hendrik Poinar is a geneticist and biological anthropologist who focuses on extracting ancient DNA. He currently has his sights set on sequencing the genome of the woolly mammoth -- and cloning it.

This collaborative dance company is acclaimed for its mix of humor, invention, and drama. Drawing inspiration from biology (how many dance troupes would name themselves after a fungus that thrives in cow dung?), Pilobolus has created a dance vocabulary all its own.

What we call language is something more specific than communication. Language is about sharing what's in our minds: stories, opinions, questions, the past or future, imagined times or places, ideas. It is fundamentally open-ended, and can be used to say an unlimited number of things. So what does language mean for humanity, and how did we come t...

Inspired by an abalone shell, Angela Belcher programs viruses to make elegant nanoscale structures that humans can use. Selecting for high-performing genes through directed evolution, she's produced viruses that can construct powerful new batteries, clean hydrogen fuels and record-breaking solar cells. In her talk, she shows us how it's done.

Louie Schwartzberg is a cinematographer, director and producer who captures breathtaking images that celebrate life -- revealing connections, universal rhythms, patterns and beauty.

In this eye-opening talk, conservationist Ocean Ramsey explains why sharks -- highly intelligent marvels of evolution -- are actually an essential part of the ocean's ecosystem.

From deep in the TED archive, Danny Hillis outlines an intriguing theory of how and why technological change seems to be accelerating, by linking it to the very evolution of life itself. The presentation techniques he uses may look dated, but the ideas are as relevant as ever.

Consider the claw. Frequently found on animals around the world, it's one of nature's most versatile tools. Bears use claws for digging as well as defense. An eagle's needle-like talons can pierce the skulls of their prey. Even the ancestors of primates used to wield these impressive appendages, until their claws evolved into nails. So what caus...

An insect's ability to fly is one of the greatest feats of evolution. Michael Dickinson looks at how a fruit fly takes flight with such delicate wings, thanks to a clever flapping motion and flight muscles that are both powerful and nimble. But the secret ingredient: the incredible fly brain.

In a mesmerizing set, musician Nora Brown breathes new life into two old-time banjo tunes: "East Virginia" and "John Brown's Dream." An evocative performance paired with a quick history of the banjo's evolution.

In cities, evolution occurs constantly, as countless plants, animals and insects adapt to human-made habitats in spectacular ways. Evolutionary biologist Menno Schilthuizen calls on peculiar beings such as fast food-loving mice and self-cooling snails to illustrate the ever-transforming wonders of urban wildlife -- and explains how you can obser...

A handful of species on Earth share a seemingly mysterious trait: a menstrual cycle. We're one of the select few mammals on Earth that menstruate, and we also do it more than any other animal, even though it's a waste of nutrients, and can be a physical inconvenience. So where's the sense in this uncommon biological process? TED-Ed describes the...

Harvard psychologist Dan Gilbert says our beliefs about what will make us happy are often wrong -- a premise he supports with intriguing research, and explains in his accessible and unexpectedly funny book, Stumbling on Happiness.

Harvey Fineberg studies medical decisionmaking -- from how we roll out new medical technology, to how we cope with new illnesses and threatened epidemics.

Two Pilobolus dancers perform "Symbiosis." Does it trace the birth of a relationship? Or the co-evolution of symbiotic species? Music: "God Music," George Crumb; "Fratres," Arvo Part; "Morango...Almost a Tango," Thomas Oboe Lee.

Denis Dutton was a philosophy professor and the editor of Arts & Letters Daily. In his book The Art Instinct, he suggested that humans are hard-wired to seek beauty.

In his book "Homo Deus," Yuval Noah Harari explores the future of humankind: the destinies we may set for ourselves and the quests we'll undertake.

Sharing the results of a massive, worldwide study, geneticist Svante Pääbo shows the DNA proof that early humans mated with Neanderthals after we moved out of Africa. (Yes, many of us have Neanderthal DNA.) He also shows how a tiny bone from a baby finger was enough to identify a whole new humanoid species.

The human brain is puzzling -- it is curiously large given the size of our bodies, uses a tremendous amount of energy for its weight and has a bizarrely dense cerebral cortex. But: why? Neuroscientist Suzana Herculano-Houzel puts on her detective's cap and leads us through this mystery. By making "brain soup," she arrives at a startling conclusion.