The human axillary organ: An evolutionary puzzle

Abstract

The human axillary organ: an evolutionary puzzleIn the cavum axillae of humans lies a glandular organ composed of tightly packed apocrine glands with secrete a colourless, or slightly pigmented fluid -the so-called axillary organ. It develops during childhood but remains inactive until the onset of sexual maturity when it grows hairs and embarks on a lifetime of secretion. A similar structure occurs in African apes but in no other Primates. Being equally well-developed in males and females the axillary organ is not a secondary sexual characteristic, even though it produces secretions rich in steroidal compound relating to sex and sexual status. It is argued that, with the development of gregariousness, the brain's recognition template for odorous oestrus advertisement was blocked in order to protect the bond between parents which was necessary for ensuring maximum offspring survival. The axillary organ took on a new role, namely to provide odorous stimulation for strengthening the pairbond, and lost its previous role as advertiser of individuality.