La forma e la taglia del naso si sono geneticamente evoluti, per adattarsi alle diverse tipologie di clima sulla Terra. Sono le conclusioni di uno studio presentato ieri, giovedì, sulla testata scientifica statunitense PLOS Genetics.
Ricerche del passato avevano già avanzato una precisa ipotesi: ossia che le persone con antenati viventi in climi caldi e umidi tenderebbero ad avere narici più larghe, rispetto a quelle discendenti da popolazioni delle regioni fredde e secche.
Le narici più strette consentono peraltro di accrescere l'umidità dell'aria, riscaldandola. Ciò è certamente apprezzabile nelle regioni con climi più rigidi, tanto più che l'aria fredda e secca risulta nociva per le vie respiratorie.
Gli esiti dello studio presentato ieri suffragano quelli legati alle precedenti ricerche. Un'equipe scientifica ha utilizzato immagini tridimensionali per misurare la forma dei nasi di 476 persone, i cui antenati vivevano nel sud e nell'est dell'Asia, in Africa occidentale e nell'Europa del nord.
Red.MM/ARi
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