Key insights

• ⚖️ Menstruation prepares the body for pregnancy by shaping a suitable environment for a fetus.
• ⚔️ Pregnancy creates a conflict of interests between the mother and the fetus due to genetic differences.
• 🩸 Placental features in humans and few other species allow the fetus to access the mother's circulatory system and affect her hormones.
• 🤰 Fetuses have unrestricted access to the mother's blood supply, leading to hormonal changes and potential health risks for the mother.
• 🔬 Menstruation plays a role in the screening process of embryos for viability and invasiveness during pregnancy.
• 🧬 The body removes failed embryos and unfertilized eggs to avoid risks and infection, leading to menstruation.
• 🔐 Menstruation is a protective process that removes possible risks and ensures the continuation of the human race.

Q&A

• How does menstruation ensure the continuation of the human race?

  Menstruation is a protective process that removes possible risks, such as failed embryos that don't attach properly or die, unfertilized eggs, and tissues disrupted by sick, dying, or dead embryos. By avoiding risks and infection, menstruation ensures the continuation of the human race.

• How does menstruation play a role in screening embryos during pregnancy?

  Pregnancy involves screening embryos for viability and invasiveness, and menstruation plays a role in the process of implantation. The endometrium evolved to make implantation difficult to select for healthy embryos, creating an evolutionary feedback loop in the process of embryo screening.

• How does the fetus's access to the mother's blood supply impact the mother?

  Fetuses have unrestricted access to nutrient-rich blood and can lead to hormonal changes in the mother. If the fetus develops poorly or dies, it can pose potential health risks for the mother due to these hormonal changes and the impact on her physiology.

• What unique placental features exist in humans and a few other species?

  The placenta in humans and a few other species penetrates the mother's circulatory system. This allows the fetus to directly access the mother's bloodstream and affect her hormones, which is a unique feature not present in most mammals.

• Why does pregnancy create a conflict of interests between the mother and the fetus?

  Pregnancy creates a conflict of interests between the mother and the fetus due to genetic differences. The human body evolved to promote the spread of its genes. The fetus inherits genes from its father, which can lead to a conflict of interests with the mother, resulting in an evolutionary conflict of interests.

• What purpose does menstruation serve?

  Despite being a waste of nutrients and a physical inconvenience, menstruation prepares the body for pregnancy by shaping a suitable environment for a fetus. The biological process of menstruation serves the purpose of creating an internal haven for a mother to nurture her growing child during pregnancy.

• 00:06 Few species, including humans, undergo menstruation despite its drawbacks, but it serves the purpose of preparing the body for pregnancy.
• 00:46 Pregnancy is awe-inspiring, but it creates a conflict of interests between the mother and the fetus due to genetic differences.
• 01:25 Humans and a few other species have unique placental features that allow the fetus to access the mother's circulatory system and affect her hormones.
• 02:05 Fetuses have unrestricted access to the mother's blood supply, which can lead to hormonal changes and potential health risks for the mother if the fetus develops poorly or dies.
• 02:49 The body screens embryos during pregnancy, with menstruation playing a role in the process. The endometrium makes implantation difficult to select for healthy and invasive embryos.
• 03:37 The body removes failed embryos and unfertilized eggs to avoid risks and infection, leading to menstruation. This biological trait ensures the continuation of the human race.