Evolution. Male rivalry extends to sperm in female reproductive tract.
Pennisi
Elizabeth
E
D000818:Animals; D001000:Ants / Q000502:physiology*; D001516:Bees / Q000502:physiology*; D004330:Drosophila / Q000502:physiology*; D005260:Female; D005306:Fertilization; D005836:Genitalia, Female / Q000502:physiology; D008297:Male; D012098:Reproduction; D012661:Semen / Q000737:chemistry* / Q000502:physiology; D012726:Sexual Behavior, Animal; D013094:Spermatozoa / Q000502:physiology*