Editing Mole (animal) (section)

==Characteristics==

===Underground breathing===
Moles have been found to tolerate higher levels of carbon dioxide than other mammals, because their blood cells have a special form of [[hemoglobin]] that has a higher [[Ligand (biochemistry)#Receptor/ligand binding affinity|affinity]] to [[oxygen]] than other forms. In addition, moles use oxygen more effectively by reusing the exhaled air, and can survive in low-oxygen environments such as burrows.<ref>{{cite news
 | title = Secret of how moles breathe underground revealed
 | newspaper = The Telegraph | date = 20 July 2010
 | url = https://www.telegraph.co.uk/science/science-news/7899216/Secret-of-how-moles-breathe-underground-revealed.html |url-status=dead |archive-url=https://web.archive.org/web/20100723133025/http://www.telegraph.co.uk/science/science-news/7899216/Secret-of-how-moles-breathe-underground-revealed.html |archive-date=23 July 2010 |access-date=19 August 2016
}}</ref>

===Extra thumbs===
[[File:Talpa europaea MHNT pate.jpg|thumb|Mole [[paw]]]]
Moles have [[polydactyl]] forepaws: each has an extra thumb (also known as a prepollex) next to the regular [[thumb]]. While the mole's other digits have multiple joints, the prepollex has a single, sickle-shaped bone that develops later and differently from the other fingers during [[embryogenesis]] from a transformed [[sesamoid bone]] in the [[wrist]], independently evolved but similar to the [[giant panda]] thumb. This supernumerary digit is species-specific, as it is not present in [[shrew]]s, the mole's closest relatives. [[Androgenic steroid]]s are known to affect the growth and formation of bones, and a connection is possible between this species-specific trait and the male genital apparatus in female moles of many mole species ([[gonad]]s with testicular and ovary tissues).<ref>{{cite web
 |title       = How the mole got its twelve fingers
 |publisher   = University of Zurich
 |date        = 12 July 2011
 |url         = http://www.mediadesk.uzh.ch/articles/2011/maulwurf_en.html
 |url-status  = dead
 |archive-url  = https://web.archive.org/web/20110723164207/http://www.mediadesk.uzh.ch/articles/2011/maulwurf_en.html
 |archive-date = 23 July 2011
 |access-date = 17 July 2011
}}</ref>