Even if you accept the notion that nature has no obligation to make sense, echinoderms are enigmas that evolved like no other animals on earth. Their curtain went up over half-a-billion years ago, along with those of all the other basic blueprints for building an animal, but they tell an entirely different evolutionary story.
Our particularly intimate relationship with molluscs is due largely to their tasty, fleshy bodies, which have been an easy meal for millions of other animals in the food web since they first emerged during the Cambrian explosion. With that kind of vulnerability, and because they couldn’t outrun predators, early molluscs came up with armor to survive. It's a fascinating story.
Read the latest chapter, Armor and Speed, the Survival Game, adapted from the Shape of Life book.
Must be nice. Sitting around all day while your food comes to you. Just spinning and grabbing grub from all directions. Learn what ancient solutions can teach us today with the Mollusc's merry-go-round radial symmetry in our new Mollusc lesson plan.
In general these lessons ply an “explore-before-explain” pedagogy, in which students make and interpret observations for themselves as a prelude to formal explanations and the cultivation of key scientific concepts. There are splashes of inquiry and scientific process using authentic data, and students are pressed to think at higher cognitive levels. Instruction is organized around three unifying themes – the macroevolutionary patterns of divergence, convergence, and coevolution – and students learn to interpret diverse biological phenomena of these patterns.
Over the millions of years that animals have been living on earth, they have learned to exploit every available source of food and to do that, many have become hunters of other animals. At some point in the distant past, the first animals capable of actively hunting showed up with bodies suited for the job, and lions, tigers, sharks, people and all the rest of the world’s hunters inherited their tools. The earthworm predators of Scotland, giant tapeworms in Mississippi, and parasitic flatworms that wreck hundreds of thousands of human lives are the descendants of those first hunters that have carried their body architecture into the present. They don’t make very good company, but they have a heck of a story to tell.
Origins: Animal Eve, a newly revised chapter from The Shape of Life book, is a comprehensive resource on sponges.
For most of human history we weren’t even sure that sponges were animals. Two thousand years ago, they were listed among Aristotle’s ‘Intermediates,’ somewhere between plants and animals. His confusion is understandable to anyone who has ever seen, but not looked too closely at a sponge, which has no head, no brain, no bones, no mouth, and no internal organs. Sponges come in an astonishing variety of shapes that to us look like cups, fans, tubes and colorful, crusty smears on rocks and coral. They range in size from a few millimeters wide to more than a meter tall, like the great barrel-like glass sponge that lives in Antarctic waters. All sponges are aquatic, tied permanently to the water by their lifestyle and body plan. Of the 10,000 species alive today, only 150 live in fresh water, the rest in the ocean. Read the full chapter...
LATEST RELEASE FROM THE SHAPE OF LIFE BOOK. The Next Segment - An Explosion of Life
"What I like doing the most is actually getting out, getting down, getting dirty in the mud with the worms themselves. Getting out there whether it’s pouring rain, whether it’s a low tide at dawn, I don’t care. I just like to be out there with the worms, seeing them in their own habitat."
DAMNHAIT MCHUGH, BIOLOGIST
We keep expanding our resources to better serve you. Now you can read the Shape of Life book right from our website. Every month we’ll be featuring a new chapter. For now, please read about the brilliant Cnidarians who set the animal life in motion.
The Shape of Life series provides FREE classroom media to science teachers and includes over 80 short video segments based upon the exquisite PBS series on the evolution of the animal kingdom on planet earth. These videos are available for streaming, download or on DVD. The Shape of Life website is a complementary resource for teachers to share their classroom experiences and obtain additional resources.