Added a subsection under "Physiology" to describe the effects of recent human evolution on Freediving within diving populations like the Sama-Bajau, and organized the section slightly.
In addition to general [[Adaptation|adaptations]] within the [[human species]], Freediving is an example of an activity that has been directly affected by [[recent human evolution]]. The [[Bajau]], or “[[Sea nomads|Sea“Sea Nomads]],” have engaged in Freediving for thousands of years, and [[natural selection]] has led to larger [[spleen]] sizes. This serves as an [[oxygen]] reservoir when diving. It is theorized that other isolated diving populations globally may have experienced the same selection.<ref>{{cite journal|last1=Ilardo|first1=M. A.|last2=Moltke|first2=I.|last3=Korneliussen|first3=T. S.|last4=Cheng|first4=J.|last5=Stern|first5=A. J.|last6=Racimo|first6=F.|last7=de Barros Damgaard|first7=P.|last8=Sikora|first8=M.|last9=Seguin-Orlando|first9=A.|last10=Rasmussen|first10=S.|last11=van den Munckhof|first11=I. C. L.|date=April 18, 2018|title=Physiological and Genetic Adaptations to Diving in Sea Nomads|journal=Cell|volume=173|issue=3|pages=569–580.e15|doi=10.1016/j.cell.2018.03.054|pmid=29677510|doi-access=free|first17=E.|last12=ter Horst|first12=R.|first16=R.|last16=Nielsen|first15=S.|last15=Salingkat|first14=M. G.|last14=Netea|first13=L. A. B.|last13=Joosten|last17=Willerslev}}</ref>
