Warm Climates Support Longer Limbs

Animals that live in cold climates tend to have stubby limbs—shorter arms and legs—even smaller ears and tails. Picture a penguin and you’ll see what I mean. Biologists have long assumed that these stumpy appendages are an evolutionary adaptation. Shorter extremities minimize heat loss, so animals that are more compact are better suited to the cold.But scientists from Ohio say that temperature may have a more direct effect on the length of an animal’s limbs. Because they find that turning up the heat helps cartilage grow—results that were published in the Proceedings of the National Academy of Sciences.The researchers raised mice at several different temperatures, and they confirmed that those kept at a balmy 80 degrees were longer limbed than those who lived at a more chill 45. But how does a little heat make mice more leggy? The answer, they find, lies in the cartilage. Long bones grow from the cartilage found at either end. And the warmer it is, the more that cartilage grows, even when it’s just sitting in a test tube. Which I guess means it’s possible that the dog days of summer lead to longer-legged dogs.

Words

stubby：斷株一般的，短而粗硬的，粗而短的。stub：殘端，殘段，殘牙，殘肢，菸蒂

stumpy：多殘株的，粗短的，矮胖的。stump：樹樁，菸頭，殘餘

appendage：[əˈpendɪdʒ].附加物，附屬肢體

extremity：前端，末端，四肢，手腳，極端，困境，極點

compact：使緊密，使簡潔，壓緊，結實地組成，訂立契約

turn up：出現，發生，開大

cartilage：[ˈkɑ:tɪlɪdʒ].軟骨

軟骨：人類骨骼中一種緻密的結締組織。軟骨由深埋在堅實的凝膠狀基質中的緻密膠原纖維網所組成，不含血管。軟骨可分三種：①透明軟骨分佈最廣，組成胚胎的骨架，並持續存在於成人活動關節的骨端、肋骨末端及鼻、喉、氣管、支氣管中。②纖維軟骨構成椎間盤的纖維環，極為堅韌。③彈性軟骨中除膠原纖維外還含有彈性纖維，因此最為柔韌；人類的外耳即由彈性軟骨構成。在胚胎期，人的大部分骨骼由軟骨構成，以後才被骨取代（大英百科）。

balmy：

溫和的，柔和的，芬芳的，芳香的，宜人的。balm：香油，安慰物，香膏

leggy：長腿的，莖長的，腿細長的

test tube：試管

dog days：大熱天，不利時期，三伏天，淡季

古羅馬人把the Dog Star（天狼星,又稱Sirius）與太陽一起出沒的期間，即自七月三日起至八月十一日止的四十天稱為 dog days。他們相信這期間由於太陽的熱度加上光度極強的天狼星的熱度會形成酷暑。