Related Experiment Video
Updated: May 27, 2026

Incremental Temperature Changes for Maximal Breeding and Spawning in Astyanax mexicanus
Published on: February 14, 2021
The effect of altitude on fertility in Andean countries
Abstract:
Abstract In papers previously published in this journal J. M. Stycos and D. M. Heer have shown that fertility is lower in the economically underdeveloped Indian-speaking parts of Peru, Ecuador and Bolivia than in the more prosperous Spanish-speaking parts. Stycos concluded that the reason for the fertility difference in Peru is the greater marital instability of the Indian speakers which decreased their total exposure to the risk of conception. Heer suggested instead that the causes of the difference may be voluntary. The present paper questions Heer's analysis, and offers the explanation that the difference may be attributed to the physiological effects of altitude.
Related Concept Videos
Spermatogenesis
Infertility in Males
Factors Affecting Respiration
Infertility in Females
Endometriosis, a condition characterized by abnormal growth of endometrial...
Gonadal and Placental Hormones
In males, testosterone is the primary gonadal androgen. It plays a central role in the maturation of male reproductive organs — the penis and testes. Additionally, testosterone is instrumental in the development of secondary sexual characteristics — a deep voice as well as facial and pubic hair growth — and...
Variation of Atmospheric Pressure
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...