Editing Inca Empire (section)

== Adaptations to altitude ==
The people of the Andes, including the Incas, were able to adapt to high-altitude living through successful acclimatization, which is characterized by increasing oxygen supply to the blood tissues. For the native living in the Andean highlands, this was achieved through the development of a larger lung capacity and an increase in red blood cell counts, hemoglobin concentration, and capillary beds.<ref>{{citation |doi=10.1002/ajhb.22367 |pmid=24065360 |title=Developmental Functional Adaptation to High Altitude: Review |journal=American Journal of Human Biology |volume=25 |issue=2 |pages=151–168 |date=2013 |last1=Frisancho |first1=A. Roberto |url=https://deepblue.lib.umich.edu/bitstream/2027.42/96751/1/ajhb22367.pdf |hdl=2027.42/96751 |s2cid=33055072 |hdl-access=free}}</ref>

Compared to other humans, the Andeans had slower heart rates, almost one-third larger [[lung]] capacity, about 2 L (4 pints) more blood volume and double the amount of [[hemoglobin]], which transfers [[oxygen]] from the lungs to the rest of the body. While the [[Conquistadors]] may have been taller, the Inca had the advantage of coping with the extraordinary altitude.<ref>{{Cite journal |last=Kellog |first=RH |date=1968 |title=Altitude acclimatization, A historical introduction emphasizing the regulation of breathing |journal=Physiologist |volume=11 |issue=1 |pages=37–57 |pmid=4865521 |url=https://www.lib.umich.edu/collections/deep-blue-repositories}}</ref> The [[Tibetan people|Tibetan]]s in Asia living in the [[Himalayas]] are also adapted to living in high-altitudes, although the adaptation is different from that of the Andeans.<ref name="Gibbons">{{cite web |last1=Gibbons |first1=Ann |title=Tibertans inherited high-altitude gene from ancient humans |url=https://www.science.org/content/article/tibetans-inherited-high-altitude-gene-ancient-human-rev2 |website=science.org |access-date=18 June 2021}}</ref>