TY  - GEN
AU  - Andersson,M
TI  - Evolution. A case of male opportunism
SN  - 0028-0836
PY  - 1990///0221
KW  - Animals
KW  - Biological Evolution
KW  - Female
KW  - Male
KW  - Ranidae
KW  - physiology
KW  - Sex Characteristics
KW  - Sexual Behavior, Animal
N1  - Publication Type: Comment; News
UR  - https://doi.org/10.1038/343020a0
ER  -