Did you know that...? Well now you know!
Jul. 23rd, 2007 08:46 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
tsukikageI always wondered why un-fixed cats and such don't randomly start bleeding around the house once a year or whatever, and I found my answer when I looked up menstruation on Wikipedia: Menstrual cycles occur exclusively in humans and other great apes. The females of other mammalian species experience an estrus, in which the endometrium is reabsorbed by the animal at the end of its reproductive cycle.Menstrual cycles occur exclusively in humans and other great apes. The females of other mammalian species experience an estrus, in which the endometrium is reabsorbed by the animal at the end of its reproductive cycle.
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Date: 2007-07-24 02:50 am (UTC)no subject
Date: 2007-07-24 02:55 am (UTC)The evolutionary impetus for menstruation remains somewhat unclear. Most mammals reabsorb the uterine lining during their oestral cycle. The ancient writer Hippocrates considered that menstruation was intended to cleanse the body of "evil humours", and modern evolutionary biologist Margie Profet contends that the primary function of menstruation is to remove sperm-borne pathogens from the uterus. In support of this theory, she has pointed to the relatively high levels of macrophages in menstrual blood. Anthropologist Beverly Strassmann has posited that the energy savings of not having to continuously maintain the uterine lining more than offsets the blood loss of menstruation. Currently, however, no single explanation of the evolutionary purpose of menstruation is accepted.[4]
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Date: 2007-07-24 02:57 am (UTC)no subject
Date: 2007-07-24 02:39 pm (UTC)no subject
Date: 2007-07-24 02:41 pm (UTC)