A long train makes a peacock a worse flyer and an easier target for a hawk, and still it keeps evolving longer. Two opposing forces explain it: female preference pushes the ornament up, predation drags it back down, and the population mean settles exactly where they balance. In Zahavi handicap terms the train stays an honest signal because only a fit male can afford it, while under Fisherian runaway the preference and the ornament escalate together.
A long train makes a peacock a worse flyer and an easier target for a hawk, and still it keeps evolving longer. Two opposing forces explain it: female preference pushes the ornament up, predation drags it back down, and the population mean settles exactly where they balance. In Zahavi handicap terms the train stays an honest signal because only a fit male can afford it, while under Fisherian runaway the preference and the ornament escalate together.
Related topics in Living World