Why???????

網上兩個說法:
第一說法
印第安那大學
Male nipples aren't exactly a genetic glitch: they are evidence of our developmental clock. In the early stages of life from conception until about 14 weeks, all human fetuses look the same, regardless of gender. At the tender age of 14 weeks post-fertilization , genetically-male fetuses begin to produce male hormones including testosterone. These hormones turn the androgynous fetus into a bouncing baby boy.
Here's where the developmental clock comes in. By 14 weeks, when the hormones turn on, the nipples have already formed. So, while our male fetus goes on to become a baby boy, he keeps his nipples, reminding all of us that people, male and female, started off the same way. http://amos.indiana.edu/library/scripts/nipples.html
和shirleylau2006di 說法差不多, 不同在這裡說14星期不是六個月
第二說法
“….人類性發育過程中固有自然物的附產品，比如，男性的乳頭，和潛藏在女性卵巢後方的退化器官———輸精管。還有些器官已經明顯地失去了功能，但還是頑固地長在人體上，它的繼續存在就是因為還沒有讓它退出基因庫的充分理由…”
http://society.eastday.com/eastday/news/node37955/node37958/node37990/node51750/userobject1ai900370.html

同肚臍原理一樣??
有什麼關係?
“男性唔需要俾養分胎兒,都要有臍帶”?
臍帶不單俾養份
胎兒(無論男女)都要臍帶把養份從母體中吸收
不是唔需要俾養分就不用臍帶

同肚臍原理一樣!!

同肚臍原理一樣!
你會問,點解男性唔需要俾養分胎兒,都要有臍帶?
好簡單,人人阿媽都係女既,佢地有呢兩樣野,
咁如果肚裡面果個bb冇呢兩樣黎接收養分
咁佢地唔通用口食咩!

男性乳頭係冇用的,
當胚胎係媽媽個肚到六個月果陣,
男性既表徵仲同女性一樣..
咁點解男性有乳頭?
因為男性表徵退唔切胚胎就會出世LU..
所以男性乳頭仲係到.