Crash Course Zoology | Diversity of Bodies & Sizes (but mostly crabs) | Episode 3 | PBS

Even though animals can look very different on their surface, there are surprising similarities in how they’ve evolved to solve major problems - like how to support and move their bodies. Today, we’ll take a look at the various ways animals can grow, learn how and why some animals evolved to have a head and others evolved to not have a head, and examine the different types of skeletons.