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Sunday, November 22, 2009

Photo: Big Testes or Big Horns? It's One or the Other for Male Beetles


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Males from most horned beetle species, such as the Onthophagus nigriventris seen here, have faced an evolutionary trade-off to ensure their reproductive success, a new study suggests. The insects can either increase the size of defensive weapons or make bigger sperm—not both.

Photograph courtesy PNAS