Breast development extension adrenocorticotropic hormone (ACTH)), and thyroid hormones such as thyroxine (and by extension thyroid-stimulating hormone (TSH) and thyrotropin-releasing hormone (TRH)) also play permissive but less well-understood/poorly-characterized roles in breast development during both puberty and pregnancy, and are required for full functional development. Leptin has also been found to be an important factor in mammary gland development, and has been found to promote mammary epithelial cell proliferation. In contrast to the female-associated sex hormones, estrogen and progesterone, the male-associated sex hormones, the androgens, such as testosterone and dihydrotestosterone (DHT), powerfully suppress the action of estrogen in the breasts. At least one
Human male sexuality with a male, and decrease the chance that the female will mate with another male. There are several strategies by which sexual coercion can be achieved. These are harassment, intimidation, and forced copulation (rape). Thornhill and Palmer's "A Natural History of Rape" investigates the evolutionary causes of sexual coercion, particularly of rape, and suggest that such behaviour is a result of sexual selection, rather than Darwinian natural selection. Of ten listed hypotheses, they accepted two reasonable hypotheses: Thornhill and Palmer argue that these two theories are the strongest of the ten for several reasons. For example, both hypothesis argue rape