By Susan Milius
Willing to stand between the neighborhood bully and your pal next door?
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2006/05/5883.jpg?resize=150%2C92&ssl=1)
California lizards doing just that may have a genetic quirk that scientists have been looking for since the 1960s but hardly ever found.
The search for the genetic phenomenon began as theorists wondered why altruism doesn’t just self-sacrifice itself out of existence, explains Andrew G. McAdam of Michigan State University in East Lansing.