Estereótipos culturais que influenciam as perguntas que fazemos acerca da biologia da reprodução...
"Once in the oviduct, sperm are temporarily bound to the inner surface, and only some are released and allowed to approach the egg. [...] evolution has evidently led to a series of obstacles in the female reproductive tract that strictly limit the number of sperm allowed to surround an egg. [...] the female’s role in fertilisation is by no means as passive as is often assumed. [...] The entrenched notion that human sperm, once ejaculated, engage in a frantic race to reach the egg has completely overshadowed the real story of reproduction, including evidence that many sperm do not dash towards the egg but are instead stored for many days before proceeding. It was long accepted as established fact that human sperm survive for only two days in a woman’s genital tract. However, from the mid-1970s on, mounting evidence revealed that human sperm can survive intact for at least five days. An extended period of sperm survival is now widely accepted, and it could be as long as 10 days or more. [...] Another dangerous misconception is the myth that men retain full fertility into old age, starkly contrasting with the abrupt cessation of fertility seen in women at menopause. Abundant evidence shows that, in men, sperm numbers and quality decline with increasing age. Moreover, it has recently emerged that mutations accumulate about four times faster in sperm than in eggs, so semen from old men is actually risk-laden."
"Once in the oviduct, sperm are temporarily bound to the inner surface, and only some are released and allowed to approach the egg. [...] evolution has evidently led to a series of obstacles in the female reproductive tract that strictly limit the number of sperm allowed to surround an egg. [...] the female’s role in fertilisation is by no means as passive as is often assumed. [...] The entrenched notion that human sperm, once ejaculated, engage in a frantic race to reach the egg has completely overshadowed the real story of reproduction, including evidence that many sperm do not dash towards the egg but are instead stored for many days before proceeding. It was long accepted as established fact that human sperm survive for only two days in a woman’s genital tract. However, from the mid-1970s on, mounting evidence revealed that human sperm can survive intact for at least five days. An extended period of sperm survival is now widely accepted, and it could be as long as 10 days or more. [...] Another dangerous misconception is the myth that men retain full fertility into old age, starkly contrasting with the abrupt cessation of fertility seen in women at menopause. Abundant evidence shows that, in men, sperm numbers and quality decline with increasing age. Moreover, it has recently emerged that mutations accumulate about four times faster in sperm than in eggs, so semen from old men is actually risk-laden."
