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  • Imagine swimming in the ocean. You're  splashing around, minding your own business,  

    想象一下在海里游泳。你在四處嬉戲,管好自己的事。

  • when all of a sudden a shark fin the size  of a boat pops out of the water and heads  

    忽然,一個像船一樣大的鯊魚鰭從水裡跳出來,向我們走來。

  • straight towards you. That would probably be  the last time you stepped foot in the ocean,  

    徑直走向你。那可能是你最後一次踏入大海。

  • if you made it out alive that is. The only  shark that could have a dorsal fin of that  

    如果你能活著出來的話。唯一能有這樣背鰭的鯊魚

  • size would belong to a megalodon. Luckily  for youand all of usthe megalodon went  

    屬於巨齒鯊的尺寸。對你和我們所有人來說,幸運的是,巨齒鯊去了

  • extinct around 3.6 million years ago. But what  caused this massive apex predator to die off?  

    大約在360萬年前滅絕了。但是,是什麼導致了這種巨大的頂級掠食者的消亡?

  • And is there a chance that it is still  lurking in the depths of the oceans?

    而它是否有可能仍然潛伏在海洋深處?

  • The megalodon or Carcharocles megalodon first  inhabited the oceans of planet Earth around  

    巨齒鯊(Carcharocles megalodon)最早在地球上的海洋中棲息,大約是在20世紀80年代。

  • 23 million years ago. They were the largest  shark to ever live. Megalodons varied in size,  

    2300萬年前。它們是有史以來最大的鯊魚。巨齒鯊的大小不一。

  • but studies suggest that on average a female  meg could be between 45 and 59 feet long. This  

    但研究表明,平均而言,一隻雌性巨獸的長度可能在45至59英尺之間。這

  • range varies so widely because scientists need  to extrapolate the size based on teeth and jaw  

    由於科學家們需要根據牙齒和頜骨的大小來推斷,所以範圍差異很大。

  • fragments found in the fossil record. At this  point in time a full megalodon skeleton has not  

    化石記錄中發現的碎片。在這個時候,一個完整的巨齒鯊骨架還沒有

  • been found. However, from the remains we do haveit is clear that these creatures were enormous.  

    被發現。然而,從我們所掌握的遺蹟來看,這些生物顯然是巨大的。

  • Adult megalodons had no predators because  of their massive body size. The shark's  

    成年巨齒鯊因其巨大的身體尺寸而沒有捕食者。鯊魚的

  • main prey was small whales. That's rightthey ate whales, that's how big they were.

    主要的獵物是小鯨魚。沒錯,他們吃鯨魚,這就是他們的規模。

  • Megalodons roamed every ocean of  the world, although they stayed away  

    巨齒鯊遊蕩在世界的每一個海洋,儘管它們遠離了

  • from the polar regions where the water would  be too cold. What we know about the megalodon  

    來自極地的水會太冷。我們對巨齒鯊的瞭解

  • species comes from fossil remains, and scientific  observations of their much smaller relatives that  

    這些物種來自於化石遺蹟,以及對其更小的親屬的科學觀察。

  • live today. The largest predatory shark  species alive today is the great white.  

    生活在今天。今天活著的最大掠奪性鯊魚物種是大白鯊。

  • The largest great white ever recorded  was around 36 feet long. This makes it  

    有記錄的最大的大白鯊大約有36英尺長。這使得它

  • 20 feet shorter than the megalodonMegs were truly massive sharks.

    比巨齒鯊短20英尺。 巨齒鯊是真正巨大的鯊魚。

  • Megalodons were incredibly successful at what  they did. They outcompeted other predators for  

    巨齒鯊在它們所做的事情上是非常成功的。它們在競爭中勝過其他捕食者

  • about 20 million years, and stayed at the top of  the food chain for that entire time. Their size,  

    約2000萬年,並在整個時間內保持在食物鏈的頂端。它們的大小。

  • razor sharp teeth, and speed allowed them to  hunt and kill prey with deadly efficiency. So,  

    鋒利的牙齒和速度使它們能夠以致命的效率獵取和殺死獵物。所以。

  • what caused the Megalodon to go extinct? Why isn't  

    是什麼導致了巨齒鯊的滅絕?為什麼不

  • this incredibly successful killing  machine ruling over the oceans today?

    這個令人難以置信的成功的殺人機器今天統治著海洋?

  • There were probably several factors, but evidence  points to a few clear changes that had a big  

    可能有幾個因素,但有證據表明,有幾個明顯的變化對我們的生活產生了很大影響。

  • impact on the megalodon survival rate. Between  3 and 5 million years ago the climate began to  

    對巨齒鯊生存率的影響。在300萬到500萬年前,氣候開始變得

  • change on planet Earth. The world began to cool  as it entered the epoch known as the Plioscene.  

    地球上的變化。世界開始冷卻,因為它進入了被稱為普利斯克的時代。

  • As global temperatures dropped the oceans were  affected. One major change that occurred as  

    隨著全球氣溫下降,海洋受到影響。發生的一個主要變化是

  • temperatures cooled was that the sea levels  began to drop. This happens during ice ages,  

    氣溫的降低是海平面開始下降。這發生在冰河時期。

  • and periods of cooling, because the water of  the oceans gets trapped in ice and glaciers.  

    和冷卻期,因為海洋的水被困於冰和冰川。

  • As water gets converted into its solid form,  

    由於水被轉化為其固體形式。

  • it is removed from the oceans. This  causes the overall sea level to drop.

    它被從海洋中移除。這導致整體海平面下降。

  • The dropping of the global sea level wouldn't  have been a problem for megalodon if that was  

    全球海平面的下降對巨齒鯊來說不是問題,如果那是

  • the only change that occured, but when the  sea level dropped, new land started to form  

    這是唯一發生的變化,但當海平面下降時,新的陸地開始形成。

  • that had previously been underwater. During  the Pliocene the Isthmus of Panama began to  

    之前一直在水下的。在上新世期間,巴拿馬地峽開始了

  • take shape. The collision of tectonic plates in  the area caused volcanic activity that resulted  

    形成。該地區的構造板塊的碰撞引起了火山活動,導致了

  • in the formation of the mountains that  now stretch from North to South America.

    形成了現在從北美洲延伸到南美洲的山脈。

  • The emergence of this new land that connected the  Americas had a huge impact on the animals of the  

    這片連接美洲的新土地的出現,對美洲的動物產生了巨大影響。

  • oceans. The land that would become Central America  had been under water for millions of years,  

    海洋。將來成為中美洲的土地已經在水下存在了數百萬年。

  • meaning that there was nothing blocking marine  species from crossing between what would become  

    這意味著,沒有任何東西可以阻止海洋物種在未來的 "世界 "中穿越。

  • the Atlantic and Pacific Oceans near the equator.

    靠近赤道的大西洋和太平洋。

  • Once the access between the Americas was blocked  off by land, many species were now stuck either  

    一旦美洲之間的通道被陸地阻斷,許多物種現在要麼被困於

  • on one side of the continents or the other. This  meant that access to some of megalodon's prey may  

    在大陸的一側或另一側。這意味著獲得巨齒鯊的一些獵物可能是

  • have been separated from them. Ocean currents and  movement of nutrients in the oceans began to shift  

    已經與它們分離。洋流和海洋中的營養物質的運動開始轉變

  • once the equatorial connection between the oceans  was impeded. This would have caused species to  

    一旦各大洋之間的赤道連接受到阻礙。這將導致物種在

  • migrate to new areas, or if they could not adjust  to the new environment they would go extinct.

    遷移到新的地區,或者如果它們不能適應新的環境,它們就會滅絕。

  • The currents and nutrients that once flowed  between the Americas would have been abruptly  

    曾經在美洲之間流動的洋流和營養物質會突然間被

  • brought to a halt. Without these nutrientsbiodiversity would drop. This change would  

    導致停滯。沒有這些營養物質,生物多樣性就會下降。這種變化將

  • have a domino effect on all species living  throughout the oceans. Nutrients would no  

    對生活在海洋中的所有物種產生多米諾骨牌效應。營養物質將不會

  • longer be where they once were, and entire  ecosystems would have vanished. This alone  

    他們不再是以前的地方,整個生態系統將消失。僅這一點

  • would have caused mass extinctions of aquatic  organisms, leaving room for new species to evolve.

    會造成水生生物的大規模滅絕,為新物種的進化留下空間。

  • Even if this lowering of ocean levelsand the blockage between the oceans,  

    即使這種海平面的降低,以及海洋之間的阻隔。

  • did not directly cause megalodon to go extinctit most likely had an impact on their prey.  

    這並不直接導致巨齒鯊的滅絕,但很可能對它們的獵物產生了影響。

  • Since megalodon was large and slow to  reproduce, it filled one specific niche,  

    由於巨齒鯊體型龐大,繁殖緩慢,它填補了一個特定的利基。

  • that of apex predator. If the environment  suddenly changed, it was unlikely that  

    這就是頂級捕食者。如果環境突然發生變化,就不太可能

  • megalodon had the genetic diversity to  adapt to a new environment with less prey.

    巨齒鯊具有遺傳多樣性,能夠適應獵物減少的新環境。

  • Another impact of the lowering of ocean levels  is that the oceans become saltier. As more  

    海平面降低的另一個影響是,海洋變得更鹹。隨著更多

  • and more water is trapped in ice and glaciers  the salt to water ratio in the ocean changes.  

    越來越多的水被截留在冰和冰川中,海洋中的鹽和水的比例發生了變化。

  • The salt does not get trapped with the water, so  salt levels remain constant, while water levels  

    鹽不會與水困在一起,是以鹽的水準保持不變,而水的水準則保持不變。

  • decrease. This causes an increase in salinity  throughout parts of the oceans. The difference in  

    減少。這導致整個海洋部分的鹽度增加。差異

  • saltiness would have shifted the ocean currentsand nutrient cycles, ever more. In fact,  

    鹹度會使洋流和營養物質循環發生更大的變化。事實上。

  • this change in salinity is one of the main  reasons we have the ocean conveyor belt of today.

    這種鹽度的變化是我們擁有今天的海洋傳送帶的主要原因之一。

  • All of these changes to the  oceans would have meant the  

    所有這些海洋的變化將意味著

  • environment that the megalodon had been  so successful in for millions of years,  

    巨齒鯊在幾百萬年來一直如此成功的環境中。

  • was now different. It is very difficult for large  specialist predators to adapt to changes in their  

    現在不同了。對於大型專業捕食者來說,要適應它們的變化是非常困難的

  • environment. Think about what is happening in  the arctic right now to polar bears. They are  

    環境。想想現在北極地區的北極熊正在發生什麼。它們是

  • highly specialized for the environment they  evolved in, but if the ice continues to melt,  

    對於它們進化的環境來說,它們是高度專業化的,但如果冰層繼續融化。

  • and global temperature continues to rise, they  will go extinct. The polar bear species just  

    和全球溫度繼續上升,它們將滅絕。北極熊物種只是

  • does not have enough genetic diversity to allow  them to be successful in a warmer environment.

    沒有足夠的遺傳多樣性讓它們在更溫暖的環境中獲得成功。

  • As the environment changed during the Pliocenemarine diversity diminished for a while before  

    隨著上新世期間環境的變化,海洋的多樣性在一段時間內減少了,然後才是

  • natural selection caused new species to evolve  and thrive. Unfortunately, this would have taken  

    自然選擇導致新物種的進化和興旺。不幸的是,這將需要

  • thousands and thousands of years; time that the  megalodon did not have. With less biodiversity,  

    幾千年,幾萬年;巨齒鯊沒有的時間。隨著生物多樣性的減少。

  • and animals to eat, all predators in the  ocean would need to compete for similar  

    和動物的食物,海洋中的所有捕食者都需要爭奪類似的

  • food sources. The prey that megalodon  once thrived on would have diminished,  

    食物來源。巨齒鯊曾經茁壯成長的獵物會減少。

  • which meant that either they had to compete for  a different food source, or starve to death.

    這意味著,要麼他們不得不競爭不同的食物來源,要麼餓死。

  • Before the change in the environment of the  Pliocene, the oceans were filled with large marine  

    在上新世的環境變化之前,海洋中充滿了大型海洋

  • animals. Many of these animals ate krill or small  fish like the baleen whales of today. This meant  

    動物。這些動物中有許多吃磷蝦或小魚,就像今天的鬚鯨。這意味著

  • that there was an abundance of prey for megalodon  to hunt. However, after the climate shift  

    當時有大量的獵物可供巨齒鯊捕獵。然而,在氣候轉變之後

  • organisms such as toothless walruses, aquatic  sloths, and dwarf baleen whales did not survive  

    諸如無齒海象、水生樹懶和侏儒鬚鯨等生物都沒有生存下來

  • into the new environment. Slowly, but surelythe megalodons variety of food was diminished.

    進入新的環境。慢慢地,但肯定的是,巨齒鯊的食物種類減少了。

  • This is where the real problem for megalodon came  in. Changing of climate most likely contributed  

    這就是巨齒鯊的真正問題所在。氣候的變化最有可能促成

  • to the extinction of the species, but scientists  now believe there was one main culprit that drove  

    導致物種滅絕,但科學家們現在認為,有一個主要的罪魁禍首推動了

  • the nail into the coffin of the megalodon. At  around the same time as megalodon went extinct,  

    釘在巨齒鯊棺材裡的釘子。大約在巨齒鯊滅絕的同一時間。

  • a new apex predator had just started to  make its appearance, the great white shark.

    一個新的頂級掠食者剛剛開始出現,即大白鯊。

  • Carcharodon carcharias, or the great white  shark, appeared around the same time as the  

    大白鯊(Carcharodon carcharias),或稱大白鯊,大約在同一時期出現。

  • megalodon species began to decline. It would seem  this new species of shark could out compete the  

    巨齒鯊物種開始衰退。似乎這種新的鯊魚物種可以在競爭中勝過巨齒鯊。

  • megalodon. The smaller size of great whites  allowed them to catch and eat smaller prey,  

    巨齒鯊。大白鯊較小的體型使它們能夠捕捉和吃掉較小的獵物。

  • which was more abundant after the climate shiftThe ability to eat many different species,  

    這在氣候轉變後更為豐富。 有能力吃許多不同的物種。

  • other than just small whales, gave  the great whites an advantage.

    除了小鯨魚之外,大白鯊也有優勢。

  • Not only did the great white have a wider  variety of food it could choose from,  

    大白鯊不僅有更多種類的食物可以選擇。

  • but the smaller body size actually worked in its  favor. Since the megalodon had such a massive  

    但較小的身體尺寸實際上對它有利。由於巨齒鯊擁有如此巨大的

  • body it needed to stay in relatively warm watersso that it could maintain its body temperature.  

    它的身體需要呆在相對溫暖的水中,這樣它才能保持體溫。

  • Sharks are ectotherms meaning that they don't  regulate their internal body temperature,  

    鯊魚是外溫動物,這意味著它們不能調節其內部體溫。

  • but instead, rely on factors such as sunlight  and muscle movement to increase the temperature  

    而是依靠陽光和肌肉運動等因素來提高溫度

  • of their bodies. The smaller bodies of the  great white sharks meant they could venture  

    他們的身體。大白鯊較小的身體意味著它們可以冒險

  • into cooler waters, since they had less body  mass to keep warm. Their muscles did not need  

    進入較冷的水域,因為他們有較少的身體品質來保持溫暖。它們的肌肉不需要

  • to work quite as hard as megalodon to keep  their body temperature up, and therefore,  

    要像巨齒鯊那樣努力工作以保持其體溫,是以。

  • they didn't need as much energy from  food as their larger cousins either.

    他們也不像他們較大的表親那樣需要從食物中獲得大量能量。

  • It was also likely that great whites hunted  some of the same prey as megalodon. Perhaps  

    大白鯊也很可能捕食一些與巨齒鯊相同的獵物。也許

  • the great whites targeted the young of  the species that megalodon was hunting,  

    大白鯊的目標是巨齒鯊正在捕獵的物種的幼崽。

  • thus reducing the amount of adult prey available  for the megalodon to eat. The great white sharks  

    是以,減少了可供巨齒鯊食用的成年獵物的數量。大白鯊

  • were by no means trying to outcompete and cause  the megalodon to go extinct, but they were,  

    他們絕不是想超越巨齒鯊,導致巨齒鯊滅絕,但他們確實如此。

  • and still are, very efficient predators, who  in the new ocean environment thrived. The great  

    現在仍然是,非常有效的捕食者,他們在新的海洋環境中茁壯成長。偉大的

  • white shark's success most likely played a role  in the extinction of the once great megalodon.

    白鯊的成功很可能在曾經偉大的巨齒鯊的滅絕中發揮了作用。

  • Scientists also think that the evolution of other  smaller species of shark could have put pressure  

    科學家們還認為,其他更小的鯊魚物種的進化可能會給他們帶來壓力。

  • on the megalodons. For example, tiger sharks  which lived during the same time as megalodon,  

    對巨齒鯊的影響。例如,與巨齒鯊生活在同一時期的虎鯊。

  • and in very similar environments, may have  contributed to the larger shark's demise.  

    而在非常相似的環境中,可能促成了大型鯊魚的消亡。

  • It has been suggested that great whites and  tiger sharks may have fed on megalodon young  

    有人認為,大白鯊和虎鯊可能以巨齒鯊的幼魚為食。

  • that had not grown to their full size  yet, causing even fewer numbers of the  

    在這一過程中,由於沒有完全長成,造成了更少的數量。

  • species to reach maturity. As we gather more  evidence, we may find that megalodon was not  

    種類達到成熟。隨著我們收集更多的證據,我們可能會發現巨齒鯊並不是

  • just outcompeted by smaller species of shark, but  their babies may have been hunted by them as well.

    鯊魚只是被較小的鯊魚種類所競爭,但它們的嬰兒也可能被它們獵殺。

  • One theory of what caused the megalodon  to go extinct is really out there,  

    關於導致巨齒鯊滅絕的原因,有一種理論確實是存在的。

  • literally. Some astronomers suggest that  a supernova may have contributed to the  

    從字面上看。一些天文學家認為,一顆超新星可能促成了

  • extinction of the largest sharks that ever livedThe claim is that a nearby star went supernova,  

    有史以來最大的鯊魚滅絕了。 聲稱是附近的一顆恆星變成了超新星。

  • enveloping the Earth in harmful muon radiationThis radiation would have been harmful to many  

    將地球籠罩在有害的μ介子輻射中。 這種輻射會對許多人造成傷害

  • species. But ones that reproduce slowly like the  megalodon, would have been affected much more  

    物種。但是像巨齒鯊這樣繁殖緩慢的物種,受到的影響會更大。

  • drastically because of the build up of mutations  and lack of genetic diversity in the species.

    由於突變的積累和物種的遺傳多樣性的缺乏而急劇下降。

  • All of these factors may have played  a role in the extinction of megalodon,  

    所有這些因素都可能在巨齒鯊的滅絕中發揮了作用。

  • but are we so sure that the species is really  extinct? Could there be a gigantic 60 foot shark  

    但我們是否確定該物種真的已經滅絕了?會不會有一條60英尺的巨大鯊魚?

  • lurking in the blackness of the oceans? Welllet's look at the evidence. Humans have been  

    潛伏在黑暗的海洋中?好吧,讓我們來看看證據。人類一直在

  • exploring the oceans, and recording their  observations, for hundreds of years. In all  

    幾百年來,他們一直在探索海洋,並記錄他們的觀察結果。在所有

  • that time there have been no reliable accountsor documentation, of megalodons being sighted.

    那時候還沒有看到巨齒鯊的可靠報道或文件。

  • If megalodons were still alive, we would at  least expect to find whales or other prey  

    如果巨齒鯊還活著,我們至少會期望找到鯨魚或其他獵物

  • with 10 foot bite marks on them from the jaws ofmegalodon. But such evidence has never been found.  

    上面有巨齒鯊下顎的10英尺咬痕。但這樣的證據從未被發現。

  • We would also expect to find at least some  megalodon fossils in layers of the Earth  

    我們還期望在地層中至少找到一些巨齒鯊的化石

  • younger than 3.5 million years old, but to  this day no such fossils have been found.

    小於350萬年,但至今沒有發現這種化石。

  • Scientists also believe that megalodons  established nurseries for their young in  

    科學家們還認為,巨齒鯊為其幼崽建立了託兒所。

  • shallow seas, which means that we should see  baby megalodons near the surface of the ocean.  

    淺海,這意味著我們應該在海洋表面附近看到小巨齒鯊。

  • Even a baby megalodon would be a massive sharkand would most definitely make the news. Yet,  

    即使是巨齒鯊寶寶也是一條巨大的鯊魚,而且肯定會成為新聞。然而。

  • this has never occurred. It is important to  remember that for any species to continue on  

    這種情況從未發生過。重要的是要記住,任何物種要想繼續發展下去

  • it needs to reproduce, and megalodons, like  all sharks and animals, don't live forever.  

    它需要繁殖,而巨齒鯊,像所有的鯊魚和動物一樣,不可能永遠活著。

  • The fact that there has never been a reliable  sighting of a full grown, or baby megalodon,  

    事實上,從來沒有一個可靠的成年巨齒鯊或小巨齒鯊的蹤跡。

  • is a good indication the  species went extinct long ago.

    是一個很好的跡象,表明該物種在很久以前就滅絕了。

  • Megladon also likely hunted in  shallower waters or near the surface,  

    Megladon也可能在較淺的水域或靠近水面的地方捕食。

  • because that was where their food source livedWhales are mammals, and therefore need to come to  

    因為那是他們的食物來源所居住的地方。 鯨魚是哺乳動物,是以需要來

  • the surface to breath air. It would seem highly  improbable that a megalodon would wait until a  

    在海面上呼吸空氣。巨齒鯊似乎非常不可能等到一個星期後才開始呼吸。

  • whale dove into the far far depths of the ocean to  attack it. For one thing, how would the megalodon  

    鯨魚潛入遙遠的海洋深處攻擊它。首先,巨齒鯊怎麼會

  • see its prey in the deep ocean where no light  reaches? Sharks have a very keen sense of smell,  

    在沒有光線照射的深海中看到它的獵物?鯊魚有非常敏銳的嗅覺。

  • but they still rely heavily on their eyes  to attack prey once they are within sight.

    但一旦獵物進入視線範圍內,它們仍然主要依靠眼睛來攻擊獵物。

  • So, no, there are no more megalodon left in the  oceans of planet Earth. And to be fair, it's  

    所以,不,地球上的海洋裡已經沒有巨齒鯊了。而且公平地說,它是

  • probably better that way. I don't know about youbut I would be much more hesitant to go swimming,  

    這樣可能更好。我不知道你的情況,但我對去游泳會更加猶豫不決。

  • or get in a boat, if I knew there was a fifty  foot killing machine swimming around the ocean.

    或者上船,如果我知道有一個50英尺長的殺人機器在海里遊動。

  • Now watchYOU vs THE MEG - How  Can You Defeat and Survive It  

    現在觀看 "你與MEG的較量--你怎樣才能打敗它並生存下來"。

  • (The Meg Shark Movie).” Or check outCROCODILE  vs GREAT WHITE SHARK - Who Would ACTUALLY Win?”

    (The Meg Shark Movie)"。或查看 "鱷魚對大白鯊--誰會真正獲勝?"

Imagine swimming in the ocean. You're  splashing around, minding your own business,  

想象一下在海里游泳。你在四處嬉戲,管好自己的事。

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B1 中級 中文 海洋 物種 鯊魚 獵物 滅絕 捕食

巨齒鯊滅絕的原因和過程(什麼殺死了巨齒鯊 (The Why and How of the Megalodon Extinction (What Killed the Giant Shark))

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    Summer 發佈於 2021 年 05 月 07 日
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