Why can't penguins fly?

Answer: Evolved for swimming efficiency

Evolved for swimming efficiency ✓ — Correct! Penguins evolved from flying birds but adapted to excel at swimming. Their wings became flippers optimized for underwater 'flight' - reaching speeds of 22 mph! The biomechanics for efficient swimming conflict with aerial flight. Dense bones (unlike hollow bird bones) help them dive deep. Evolution favored swimming specialization!

Wings are too small — Wrong. Penguin wings aren't too small—they're actually quite large relative to body size. But they evolved into flippers for swimming, with dense bones and rigid structure that can't generate flight lift.

Lost ability over time — Wrong. This implies random loss, but penguin wing evolution was purposeful adaptation. They didn't 'lose' flight ability - they traded it for superior swimming capabilities through natural selection. It was an evolutionary trade-off, not a loss.