[Frontiers in Bioscience, Landmark, 24, 712-722, March 1, 2019]

Life history tradeoffs in humans: increased life expectancy with sperm count reduction

Rui-An Wang1,2, Ping-Ju Zheng3, Yi Liu4, Lei Shang5

1Shenzhen Key Laboratory of Viral Oncology, The Clinical Innovation & Research Centre, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong Pr. 518100, China, 2Department of Pathology, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong Pr. 518100, China, 3Department of Oncology, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong Pr. 518100, China, 4Medical College, Xi’an Peihua University, Xi’an, Shaanxi Pr. 710125, China, 5Department of Health Statistics, The Fourth Military Medical University, Xi’an, Shaanxi Pr. 710032, China


1. Abstract
2. The life history tradeoff evolution theory and the principle of biorelativity
3. It is a fact that the human sperm count is declining
4. However, the causes of sperm counts reduction are extremely illusive
    4.1. Environmental pollutions
    4.2. Lifestyle changes
    4.3. Extended lifespan as the cause of sperm count reduction
5. Coda
6. Acknowledgements
7. References


Although not without controversy, as a general trend, the human sperm count is declining world-wide. One major reason for such a decline is an increase in the human life-span. According to the life history tradeoff theory, fecundity is inversely related to the lifespan; the longer the lifespan, the lower the fecundity. This is essential to the maintainance of diversity and balance of different species. Such a corrleation validated by experimental data that show that the extension of life in Caenorhabditis elegans, Drosophila and Rodents is associated with reduction in fecundity. The demographic data from a public data source, shows that the total fertility rate is positively correlated with the infant death rate, it is inversely correlated with the life expectancy. We postulate that the fall in spermatogenesis might be regulated by the neuroendocrine system that underlie human longevity.


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Abbreviations: TFR: total fertility rate; GDP: Gross Domestic Product; CIA: Central Intelligent Agent

Key Words: Life History Tradeoffs, Biorelativity, Sperm Count, Lifespan, Total Fertility Rate

Send correspondence to: Rui-An Wang, Department of Pathology, Shenzhen Hospital, Southern Medical University, Shenzhen 518100, China, Tel: 86-15829918163, Fax: 8675523360941, E-mail: ruian79@yahoo.com