Regeneration in Simple Animals
Simpler animals, such as planaria, hydras, and starfish, tend to have potent regenerative abilities.
More complex animals, such as mammals, are much more limited. Some of the disparity may be explained by tissue complexity, immune system complexity, or even strategies for avoiding cancer.
Let’s look at some examples of regeneration.
![A planaria, a hydra, and a starfish.](images/tissue-regeneration-03.png)