Scientists have been trying to grow sperm in a test tube for over 100 years, and now they've done it. Researchers in Japan "have made fertile mammalian sperm in a culture dish," reports Nature. The scientists took fragments of mouse testes and coaxed sperm to grow from them in a petri dish; then they injected the sperm into eggs, put the fertilized eggs into mice, and real, live babies came out.

This could lead to breakthroughs in fertility treatment for men. It also could lead to an exciting new line of Sea Monkeys.

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