Any animal, be it a blue whale, botfly, or human, starts out as a single, fertilized cell. Then the cell divides, differentiates, and ultimately develops into a full-fledged animal according to a special set of genetic instructions–a “toolkit” that tells the embryo how and where to develop limbs and organs. All animals on Earth use essentially the same toolkit, so embryos of different species can appear startlingly similar to one another. Here, try to match a series of embryos to their adult forms, and then watch each creature develop during a portion of its early growth.
Some of the interactives and essays:
- The Zoo of You: In this interactive, see how closely parts of your body match those in other animals, from sharks to fruit flies.
- Guess the Embryo: See if you can tell what four similar-looking embryos will become, and watch each develop.
- What is Evo Devo?: Cliff Tabin defines the new field of “evo devo” and some of the groundbreaking discoveries he and others have made.
- Gene Switches: Some genes turn other genes on and off. In this slide show, see how powerful these gene switches can be.
- Darwin’s Predictions: Over 150 years later, science continues to confirm most of Darwin’s conjectures.