Crash Course
Community Ecology: Interspecies Interactions: Crash Course Biology #6
Community ecology is the study of interactions between different species of living things, and lets ecologists examine the effects of predator-prey relationships, parasites, and mutually beneficial interactions. In this episode of Crash...
Crash Course
Intro to Ecology: Why Did All These Elephants Die?: Crash Course Biology #5
Ecology is the study of the interactions of living things with each other and their environment. It’s a field that not only lets us explore the interconnections between living things, but also how our environment affects us, and how we...
Crash Course
How Life is Organized: Crash Course Biology #4
Here on Earth, life is dizzyingly diverse—but it’s also surprisingly organized. A sense of order structures life and its processes, from the tiniest cell to the total sum of every living thing. In this episode of Crash Course Biology,...
Crash Course
Human Evolution: We Didn't Evolve From Chimps: Crash Course Biology #19
What’s a human? And how did we become humans, anyway? In this episode of Crash Course Biology, we’ll meet some of our closest relatives and trace how we evolved into the brainy, inventive, complex species we are today.
Crash Course
Biological Diversity, Butts, and the Tree of Life: Crash Course Biology #18
Everywhere you look on Earth, you’ll find wonderful and diverse living things, from tiny tardigrades to soaring sequoias. And incredibly, everything alive today, and everything that’s ever lived, is related. In this episode of Crash...
Crash Course
Population Genetics: Why do we have different skin colors?: Crash Course Biology #14
In this episode of Crash Course Biology, we’ll learn about the ways population genetics reveals how groups of living things evolve—by comparing genetic similarities and differences. We’ll discover the most genetically diverse species of...
Crash Course
Intro to Evolution: What We Can Learn From a Giraffe's Neck: Crash Course Biology #11
From a single-celled common ancestor, evolution has brought us all of Life’s Greatest Hits — including butterflies, beetles, bacteria, and human beings. In this episode of Crash Course Biology, we’ll learn how evolution explains life’s...
Crash Course
Phylogeny: How We're All Related: Crash Course Biology #17
Crocodiles, and birds, and dinosaurs—oh my! While classifying organisms is nothing new, phylogeny— or, grouping organisms by their evolutionary relationships—is helping us see life in a whole new light. In this episode of Crash Course...
Crash Course
Evolutionary History: The Timeline of Life: Crash Course Biology #16
Humans may have been around for a long time, but life has existed for way longer. In this episode of Crash Course Biology, we’ll journey through deep time to uncover the history of life on Earth. We’ll explore the big, game-changing...
Crash Course
Speciation: Where Do Species Come From?: Crash Course Biology #15
How can you tell two species apart? It’s not always simple. In this episode of Crash Course Biology, we’ll learn about speciation—a process that can happen over millions of years, or within a single generation. Along the way, we’ll...
Crash Course
Natural Selection: Life's Way of Stayin' Alive: Crash Course Biology #13
There are lots of ways that evolution happens, and natural selection is just one of them. In this episode of Crash Course Biology, we’ll find out how this process works and shapes traits in all living things —from ginkgo trees to howler...
Crash Course
Microevolution: What's An Allele Got to Do With It?: Crash Course Biology #12
Whether we’re talking about tigers, trees, or tarantulas, evolution happens at the level of the population. In this episode of Crash Course Biology, we’ll find out how natural selection, gene flow, genetic drift, and other processes...
Crash Course
The Effects of Climate Change: Crash Course Biology #9
Climate change shakes up all of Earth’s systems, including the living ones. In this episode of Crash Course Biology, we’ll see how climate change’s effects rattle the entire chain of life. Changes felt in one population ripple out to...
Crash Course
What is Climate Change?: Crash Course Biology #8
Life on Earth has weathered boiling-hot oceans and volcanic-ash-darkened skies—but that’s nothing like the climate change we’re experiencing now. In this episode of Crash Course Biology, we’ll talk about the greenhouse effect, learn why...
Crash Course
Bioinformatics: How Data Saves Lives: Crash Course Biology #40
On its own, a huge DNA sequence is a meaningless pile of data — so, how do biologists figure out what it means? They turn to the power of bioinformatics! In this episode, we’ll learn what bioinformatics is, how it works, and how...
Crash Course
DNA Structure & Replication: Our Instruction Manual for Existing: Crash Course Biology #33
Your DNA contains all the instructions your body needs to function. In this episode of Crash Course Biology, we’ll figure out what this giant instruction manual looks like and how this three-billion-letter code gets copied into your...
TED-Ed
Why don’t we get our drinking water from the ocean? | Manish Kumar
Humans have been transforming seawater into potable freshwater for millennia. Today, billions of people can’t access clean drinking water, and 87 different countries are projected to be “water-scarce” by 2050. So, how can we use seawater...
TED-Ed
Do you really need to take 10,000 steps a day? | Shannon Odell
For years, Jean Béliveau walked from country to country, with the goal of circumnavigating the globe on foot. While few people have the time or desire to walk such extreme lengths, research shows that adding even a modest amount of...
TED-Ed
A day in the life of a martial artist in medieval China | Peter Lorge
The year is 1030 CE. Chu Hong's best friend, Liang Gao, tells him that the local magistrate has been spotted holding a surprise archery competition in a nearby town and will arrive at their village soon. This is Hong’s chance to showcase...
TED-Ed
The dark history of arsenic | Neil Bradbury
No substance has been as constant an ally to insidious scheming as arsenic, the so-called “king of poisons.” In its chemically pure form, it isn’t much of a threat because our bodies don’t absorb it well; it’s when arsenic combines with...
TED-Ed
One of the most controversial medical procedures in history | Jenell Johnson
In 1935, researchers found that after removing the frontal lobes of two chimps, they no longer experienced frustration or anxiety. Neurologist Egas Moniz believed that replicating this in humans could cure mental illness— leading to one...
TED-Ed
The history of the world according to rats | Max G. Levy
Today, rats are often regarded as the most successful invasive species in the world. The most common species of rat scurried onto the scene roughly 1 to 3 million years ago in Asia. There, they craftily survived Earth’s most recent ice...
TED-Ed
What actually causes high cholesterol? | Hei Man Chan
In 1968, the American Heart Association made an announcement that would influence people’s diets for decades: they recommended that people avoid eating more than three eggs a week. Their reasoning was that the cholesterol packed into egg...
TED-Ed
The tragic romance of Tristan and Isolde | Iseult Gillespie
After witnessing a bird carrying a single golden hair, King Mark of Cornwall declared his future bride must have equally radiant locks. The only royal matching this description was Princess Isolde of Ireland. So the king sent Tristan,...