since this doesn't seem familiar to people, a little more detail:
http://slatestarcodex.com/2015/02/16/did-falling-testosteron...
https://academic.oup.com/jcem/article-lookup/doi/10.1210/jc....
https://www.ncbi.nlm.nih.gov/pubmed/17895324
https://www.wsj.com/articles/SB10001424127887323394504578607...
http://www.telegraph.co.uk/men/active/mens-health/10695991/W...
Serum testosterone levels and sperm count and quality seem to be declining. Not entirely clear it's real and not all clear why it would be happening.
Some contrary evidence: http://www.harryfisch.com/pdf/Declining%20Worldwide%20Sperm%...