Menopause
Menopause typically occurs between 49 and 52 years of age. The majority of women have their last period between the ages of 48 and 55. The average age of the last period in the United States is 51 years, in the United Kingdom is 52 years, in Ireland is 50 years and in Australia is 51 years. In India and the Philippines, the median age of natural menopause is considerably earlier, at 44 years. The menopausal transition or perimenopause leading up to menopause usually lasts 7 years (sometimes as long as 14 years).
Life history theory
There is criticism of the claim that menopause and somewhat earlier age-related declines in female fertility could coevolve with a long term dependency on monogamous male providers who preferred fertile females. This criticism argues that the longer the time the child needed parental investment relative to the lifespans of the species, the higher the percentage of children born would still need parental care when the female was no longer fertile or dramatically reduced in her fertility. These critics argue that unless male preference for fertile females and ability to switch to a new female was annulled, any need for a male provider would have selected against menopause to use her fertility to keep the provider male attracted to her, and that the theory of monogamous fathers providing for their families therefore cannot explain why menopause evolved in humans.