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2018年1月27日 星期六

From Scientific American 公的禽鳥為何沒有XX?科學人來解疑!Why Did the Chicken Lose Its Penis?







這篇報導討論公鳥生殖器為何不外露。教練給的聲音檔案都是Windows Media Player,聲音檔案是可以調整聲音速度快慢的。大家如果覺得講者說話的速度太快,記得把聲音調慢。同樣地,如果嫌講者講化速度太慢,也可以透過下面的速度設定功能,將聲音調快。
方式如下:

1. 先播放聲音檔
2. 接著對著聲音檔按滑鼠右鍵
3. 按著滑鼠右鍵後,會看到增強功能這個項目
4. 進入增強功能,接著會看到播放速度設定

進入播放速度設定後,會出現下圖這樣的玩意兒


如果想要放慢內容速度,就往左邊調整,先試試看0.8,如果還是太快,就再調一格,最慢可以調到0.5。相反地,如果想把速度加快,就往右邊移動,最快可以到2.0。

科學人Scientific American的聽力補充,是為了強化大家對科學相關英文與背景知識的能力。NPR則比較多社會科學或是藝術人文的素材。有機會多聽英文廣播絕對能讓聽力進步。另外,TED也是一個非常好的平台。記得要先耳聽眼到,多聽幾遍(精聽),過程中看熟稿子,跟著唸之後,再來盲聽(泛聽)。兩者按照順序搭配練習,絕對有用。大家加油!

Why Did the Chicken Lose Its Penis?

Only 3 percent of bird species have males with obvious organs of intromission, and now we know the genetics behind that situation. 

Most birds don’t have penises. Good, I have your attention. Of course female birds don’t have penises, but neither do most males. Now researchers have unraveled the genetics遺傳學 behind the disappearance of this anatomical apparatus生理上的構造. Their penetrating insights精闢的見解 are in the journal Current Biology.
Only 3 percent of avian species禽鳥類 have males with obvious organs of intromission插入器官. Ducks and other water fowl 家禽are fairly well endowed器官健全(碩大). But most birds have just rudimentary gear基礎配備, if anything at all.就算有,也只有陽春的配備
To get to the root of this penile puzzle, researchers compared the embryos胚胎 of chickens and ducks. Both types of birds start to develop a member. But in chickens, this so-called "genital tubercle生殖結節" shrinks before the little guys hatch孵化. And it’s because of a gene called Bmp4.
Bmp4 basically tells cells to commit suicide. This form of cell death keeps birds from sprouting teeth. And in developing male chickens, it causes the phallus to regress造成陽具內縮.
Why this happens is still a mystery. It may allow female birds to be more selective about their mates. Because males with external equipment tend to impose it where they will擁有外顯性生殖器官的雄性動物比較鴨霸. Whereas those without have to let the ladies rule the roost.擁有決定權/主宰
—Karen Hopkin



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