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  • Salt is everywhere on our planet, but some animals evolved to live in it while, others

    鹽在我們的星球上到處都是,但是有些動物演化成能夠在充滿鹽的環境中生存一段時間,其它

  • didn't; what happened there? What caused this split?

    則否;這其中發生了什麼?什麼造成了這種不同?

  • Sup salty dogs, thanks for watching DNews, I'm Trace. Water is everywhere and is one

    爆鹹熱狗,感謝您收看DNews,我是翆斯。水到處都是且是

  • of the main reasons life was able to evolve on Earth. It's pretty great. Salt is also

    生物在地球上能夠不斷演化的主因之一。這很棒。鹽也是

  • everywhere. Salt and water together, make up most of the water on our planet and it's

    無所不在。鹽和水放在一起,就是我們星球上的絕大部分水的組成方式,且

  • a major component of the beginning of life as we know it!

    這也是我們所知道的生命起源的主要組成成分!

  • Organisms need salt to survive. Salt draws water out of cells in process called osmosis.

    生物體需要鹽來維生。鹽將水分從細胞內移出的過程叫做滲透。

  • Osmosis is the tendency of water to flow across a membrane to balance salinity. Essentially,

    滲透是為了維持鹽份平衡時水流過細胞膜的方向傾向。主要是,

  • nature wants to make sure there's a balanced level of salt everywhere. This is why if you

    自然界想要維持世界各處的鹽份含量在一個平衡狀態。這是為什麼若是你

  • drink saltwater you can die of dehydration -- the water-salt balance gets out of whack

    喝海水的話,可以就會死於脫水症狀 -- 水與鹽的平衡完全被打亂

  • and water gets pulled out of your cells. It's pretty serious.

    而水從你的細胞內被抽出來。這是非常嚴重的。

  • And yet, as boney fish moved from a salty sea into freshwater (or sweetwater), they

    但是,當硬骨魚從鹹鹹的海水移居蹈淡水區(或甜水區),它們

  • had to eat salts to maintain that salt-water balance. They still do this today, urinating

    需要攝取鹽份來維持體內的鹽-水平衡。它們至今仍是如此,排泄出

  • any excess salt -- sometimes up to a third of their body weight a day. We do this too,

    任何過多的鹽份 -- 有時一天排出高達它們體重的三分之一的鹽。我們人類也會這樣,

  • which is why we crave (and love) SALT. But this brings us to the big question -- if saltwater

    也就是為何我們渴望(且愛)鹽巴。但這引出了一個大問題 -- 如果鹽水

  • fish are drinking saltwater constantly, how do they avoid dehydration due to osmosis?!

    魚喝持續喝鹽水,它們要如何避免由於滲透現象導致的脫水症狀?!

  • Well, there are two answers. One comes kind of built in. The gills of some saltwater species, like

    嗯哼,這有兩個答案。一個是內建的。一些鹽水物種的鰓,像是

  • the flatfish: turbot, have adapted to carry more of a special enzyme called "gill Na+/K+

    比目魚:大菱鮃,已經演化生成可以攜帶更多一種特別的酵素叫做 "鰓鈉鉀泵"

  • ATPase." This allows their gills to leach salt from their bodies back into the ocean.

    這使得它們的鰓得以將鹽份從它們的身體過濾排回海洋當中。

  • Without this adaptation they would die because of that high salinity.

    若是沒有發展出這樣的機制的話它們就死於如此高濃度的鹽分。

  • But, some species of eel, salmon, bass, and flounder have adaptations that let them move

    但,有些鰻魚、鮭魚、鱸魚和鰈魚種類,已經演化適應能夠

  • between fresh and saltwater! Species which can survive in a variety of salinities are

    同時生活在淡水和鹽水區!可以生活在不同鹽份濃度水域的物種

  • referred to as euryhaline; some even actively adapt their gills or their kidneysThere

    被稱為廣鹽性魚類;有些甚至會主動地改變它們的鰓或腎臟來適應...

  • are a lot of species osmoregulating in a lot of different ways. This is a great example

    有很多的物種以非常多不同方式作滲透調節。這是一個關於

  • of how evolution solves a problem along many different paths, something scientists call

    演化如何以沿著許多不同的路徑解決問題的絕佳例子,這是科學家所謂的

  • convergent evolution! SO AWESOME.

    趨同進化! 超棒的。

  • So, lemme give you a couple examples: anadromous fish, are born in freshwater and live there

    好,讓我給你幾個例子:溯河性魚類,出生於淡水區而生活在那

  • for months before they make for saltwater. In Atlantic Salmon, an enzyme called type

    幾個月後遷移至鹽水區。大西洋鮭魚體內,有種酵素叫"型II碘甲腺原氨酸脱碘酶"

  • 2 deiodinase is produced in response to the longer daylight hours in spring. Puberty ain't

    被製造出來對應春天的長日照時數。青春期的奇特

  • just weird for humans. This enzyme alters the salmon's gills, initiating osmoregulation

    不只存在人類中。這種酵素改變鮭魚的鰓,啟動滲透調節作用

  • so they can safely swim into salty water! This is reversed when they return to rivers

    讓它們能夠安全地在鹽水水域游泳!這個機制會在當它們回到河和溪中

  • and streams to breed and start the process with thier own lil' salmons.

    繁衍並跟它們自己的小鮭魚們開始新的旅程時相反。

  • And a 2013 study in Molecular & Cellular Proteomics, detailed how a DIFFERENT adaptation evolved

    而一篇2013年發表在分子與細胞蛋白質體學的期刊中,詳細描述了羅非魚如何進行

  • in tilapia. When placed into salted water gradually, the researchers found tilapia gills

    一個不同的演化適應過程,研究人員發現羅非魚的鰓演化了

  • adapted, producing a specialized protein called NDRG1. This let the tilapia survive in a saline

    能產生一種特別的蛋白質叫做NDRG1。這讓羅非魚能夠生存在鹽水

  • environment -- as long as they had time to slowly adapt.

    環境中 -- 只要它有足夠時間能夠慢慢去適應。

  • A lot fish evolution has happened in the last 400 million years. Fish have spread into pretty

    大多數的魚類演化發生在過去的4億年中。魚類已經遍佈

  • much every water-based environment on the planet. After the Great Dying 250 million

    地球上幾乎全部的水域環境當中。在2.5億年前的大滅絕之後,

  • years ago which wiped out 95 percent of all marine species, evolution had to figure out

    約95%的海洋生物從地球上消失,演化需要找到

  • how to osmoregulate again. Through an assortment of convergent evolutionary adaptations FRESHWATER

    如何再次達到滲透調節的方法。透過一個品種趨同演化適應之淡水魚類

  • fish repopulated the oceans -- learning to deal with the super-salty water. Eventually,

    重新繁殖復育重回海洋 -- 學習如何在極度鹹的水域中生活。最終,

  • they made it to land as well, when a fish named eusthenopteron evolved into amphibians

    它們也成功登陸,當魚類從名為真掌鰭魚屬演化到兩棲動物

  • -- and tetrapods -- like you and me! Without salt, and being able to regulate it, life

    -- 和四足類 -- 就像你和我一樣!雖然生活的環境中並無充斥著鹽,但依然能夠調節它,正如我們

  • as we know it wouldn't exist. Evolution is the best.

    所知這樣的生命不存在。演化是一切。

  • Salt water fish diversity is pretty incredible, thanks to evolution.

    多虧了演化的推力,海水魚所具有的多樣性十分不可思議。

  • And this year, on animal planet, River Monsters, it's all about salt water baby.

    且今年,在動物星球頻道「河中巨怪」節目中,全都在談論海水魚的後代。

  • Don't miss new episodes of river monsters every Wednesday at 9/8c on Animal Planet.

    別錯過了每週三晚上八或九點動物星球頻道所推出新的一集河中巨怪。

  • If you wonder why animals are the way they are, you belong with us here on DNews.

    你如果很好奇為何動物們是它們現在的樣貌,你就跟DNews的我們是同一掛的。

  • So subscribe, down there, and then check out this episode from Lisset and why some birds can't fly.

    所以去訂閱我們的頻道,就在下面,然後看Lisset的那一集節目:為何有些鳥類無法飛行。

  • Thanks to DNA studies, we know know that all of today's flightless birds came from ancestors that flew.

    多虧了DNA的研究,我們才能知道今日我們所見的那些無法飛行的鳥類的祖先們其實能飛,

  • but they all independently evolved to lose their ability to fly.

    但它們全都獨自演化變成失去飛行能力。

  • You wanna know somethings else about animals, and why they are the way they are?

    你想知道關於動物更多的知識,還有它們為何像今天這樣存在嗎?

  • Let us know in the comments, keep coming back here everyday, so you get more DNews.

    請在討論區留言告訴我們,記得每天都回來這兒看看,你就能看到更多DNews做的影片囉。

Salt is everywhere on our planet, but some animals evolved to live in it while, others

鹽在我們的星球上到處都是,但是有些動物演化成能夠在充滿鹽的環境中生存一段時間,其它

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