Menopause - What is it?

Menopause can be defined on so many levels depending on one’s individual experience. Some say it represents negative changes in women's lives while others propose it to represent either neutral experiences or positive change within individual woman as (Dillaway, 2005) states. However, menopause is a natural biological process that is defined as the permanent cessation of menstruation (Sherman, 1998) which affects all women around the age of 50 years old.

The depletion of ovarian follicles characterises menopause in humans (Derry, 2006). The ovarian follicles are located within the ovary as immature eggs. These eggs are surrounded by an envelope of cells that produce reproductive hormones needed for the menstrual cycle to orchestrate.

During puberty, the brain’s pituitary glands stimulate the ovaries to begin ovulation (releasing eggs each month). In preparation for the plantation of a fertilised egg, the stimulation of the pituitary glands then promotes the ovaries to release oestrogen and progesterone, thus allowing the lining of the uterus (endometrium) to thicken. A period occurs as the endometrium is shed if an egg does not become fertilised. This is known as the menstrual cycle

The number of follicles in the ovaries and level of hormones decrease as a woman ages. Menopause occurs when the period stops permanently due to the failure of the ovaries to produce enough hormones to stimulate monthly growth of the endometrium (. 2015).

Securing your genetic legacy by reproducing as many offspring as possible is seen as “winning” in the game of evolution. So it seems to be counter-intuitive that women have evolved in such a way that their fertility diminishes decades before they pass.

So my question is, how could such a maladaptive trait evolve?

References:

Dalliway, H.E. (2005). (Un)Changing Menopausal Bodies: How Women Think and Act in the Face of Reproductive Transition and Gendered Beauty Ideas. Sex Roles, 53(1-2), 1-17. Retrieved from http://link.springer.com/article/10.1007/s11199-005-4269-6.

Derry, P.S. (2006). A Lifespan biological theory of menopause. Sex Rolews. 54, 393-399.

Geary, D.C. & Flinn, M.V. 2001. Evolution of human parental behaviour and the human family. Parenting: Science and Practices, 1 (1&2), 5-61.

Sherman. P.W. (1998).l Animal Behavior; The Evolution of menopause. Nature, 392, 759-761. doi:10:1038/3385.

Wayman, E. (2013). Killer whales, grandmas and what men want: Evolutionary biologists consider menopause. Retrieved from https://www.sciencenews.org/article/killer-whales-grandmas-and-what-men-want-evolutionary-biologists-consider-menopause.

. 2015. [ONLINE] Available at: https://www.asrm.org/uploadedFiles/ASRM_Content/Resources/Patient_Resources/Fact_Sheets_and_Info_Booklets/agefertility.pdf. [Accessed 13 March 2015].