For my Assignment, I chose the article "Human Sex Ratio". I believe that I can add a section on the Environmental Impact on the Sex Ratio with how war and Economic Crisis affect the Human sex ratio for a population. I could Perhaps also find more evidence on factors that have not been discussed in the article.
James, W. H. (2009). The variations of human sex ratio at birth during and after wars, and their potential explanations. Journal of Theoretical Biology, 257(1), 116-123. 10.1016/j.jtbi.2008.09.028
Rousseau, Denis. "Hypothetical Role of Men's Sexual Activity in the Regulation of Human Sex Ratio: Analysis of the Sex Ratio of Post-War Abandoned Children." Bioscience Hypotheses, vol. 2, no. 1, 2009, pp. 43-45.
Helle, Samuli, Samuli Helama, and Kalle Lertola. "Evolutionary Ecology of Human Birth Sex Ratio Under the Compound Influence of Climate Change, Famine, Economic Crises and Wars." Journal of Animal Ecology, vol. 78, no. 6, 2009, pp. 1226-1233.
GRAFFELMAN, JAN, and ROLF F. HOEKSTRA. "A Statistical Analysis of the Effect of Warfare on the Human Secondary Sex Ratio." Human Biology, vol. 72, no. 3, 2000, pp. 433-445.
Bethmann, Dirk, and Michael Kvasnicka. "War, Marriage Markets, and the Sex Ratio at Birth." The Scandinavian Journal of Economics, vol. 116, no. 3, 2014, pp. 859-877.
Environmental impacts of war:
The Earliest account on the idea that there is a correlation between human sex ratio and war was brought up by 18th century demographer Sussmilch. He came the idea that "the high sex ratio following wars was a compensation for the men fallen in battle" Cite error: There are <ref> tags on this page without content in them (see the help page).. In the Journal of "Theoretical Biology", James referees to two theories revolving around the Human Sex Ratio at birth, during, and after wars. The Human Sex Ratio rises during and just after both World Wars. [1] Fall in Iran and other similar countries during wars. [1]. During these wars many couples were separated, leading to a decrease in the sex ratio at birth. Studies have shown that there are lower coital interactions leading to a lower fertility and a lower marriage rate. After wars former lovers reunite and are more likely to have a higher fertility and marriage rate causing a higher sex ratio. James noted that countries who were intensively involved in WWI and WWII had at least 15-22% of males at the reproductive age mobilized[1] leading to the idea revolving around the sex ratio decreasing for those countries involved heavily in these world wars. A theory revolving changes in sex ratios during wars include psychological and physical issues that arise during war. Psychological issues such as stress can cause pregnant women to disproportionately abort their child. Studies have found that the sex ratio at birth have decreased in the months following September, 11th 2000 which have been linked with an increase in spontaneous abortions. [2] Between the years 1992 and 1997 Tajikistani was involved in a civil war that caused many of the citizens of Tajikistani to flee the country. As the table below shows, during the years of the civil war the population change reduces as well as the net migration rate. All of these factors cause the Sex ratio at birth and in general to decrease due to the dangers the citizens of Tajikistan could face. Both of these Psychological and physical issues due to war can create an environmental impact of the human sex ratio [3] . [4]
Year Annual rate of population change Net Migration Rate (Per 1000 people)
1985-1990 3.04 -1.54
1995-2000 1.74 -10.85
2005-2010 1.51 -1.73
2010-2015 1.95 -2.46