Name: 這種新型冠狀病毒來自蝙蝠？我們知道的是 (Did This New Coronavirus Come From Bats? Here’s What We Know)
Uploaded: 2021-01-14T09:58:43.000Z
Duration: 4 min 36 s
Description: 【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。學這些英文用法：武漢肺炎,新型冠狀病毒,新冠肺炎,COVID-19

情態副詞

By now, you’ve probably heard of the coronavirus that’s traveling the globe.

反身代名詞

The disease it’s causing, known as COVID-19, and the virus itself, known as SARS-COV-2,

And we’re still trying to grasp where it will end up next.

So far, we know that the outbreak originated in Wuhan, China—but as of yet, how the outbreak

We’ve heard seafood, snakes, and a whole host of conspiracy theories surrounding the

virus's origin, but it seems that preliminary evidence may be pointing to an all-too-familiar

When you look at the genetic sequence of the virus, you can line it up against every other

known coronavirus and say, 'what are its closest relatives?'

It turns out that there are two viruses, one in particular that we found in China a few

years ago, that's extremely closely related: about 96% of the genetic sequence lines up

So that's really why people believe it's a bat-origin virus.

And this isn’t the first time bats have been identified as the potential source of

In fact, studies have found that bats host a much higher proportion of zoonotic viruses

than any other mammal, making them disease reservoirs.

Viruses that cause Ebola, SARS, and MERS are all zoonotic, meaning they can cross from

To better understand these zoonotic viruses, Daszak and his team have worked to sample

more than 10,000 bats in Southern China and most significantly, detected over 500 new

Now, in order to understand how SARS-COV-2 could potentially cross between species, researchers

When we find Coronaviruses in bats in China, we analyze the proteins on the surface of

those viruses and say, 'are they able to bind to human cells?', and humans have cell surface

receptors that viruses need to be able to bind to get in.

And some of these bat viruses don't; some of them do.

So probably this novel coronavirus, already had that protein that could bind.

So how exactly can bats harbor all these viruses and not be affected?

The answer could be in how bats evolved to fly.

Bats are the only mammal capable of flying long distances, and use a tremendous amount

But a byproduct of these high energy demands is believed to be an increased number of free

radicals in cells, which in turn can damage a bat’s DNA.

So to overcome these harmful effects, it seems that bats have evolved genes to dampen their

immune response, so they don’t over-react to free radical damage caused by flight.

Bats have a unique adaptation of their immune system which allows them to harbor viruses

without these viruses causing any diseases.There's a lot of influenza viruses out there.

And is only after spillover to humans that some of these viruses can

So while the bats may not get sick, when viruses make the jump to species without the same

immune strength, like say, a human, mortality rates can be high.

Environmental threats like deforestation could add to the animals' stress levels, causing

them to shed more virus through their saliva, urine, and feces, which can later infect other

So in these spillover events like the current coronavirus, a lot of focus often gets driven

But really, really important is to understand that it's about the construct that we've created

an environment where humans are suddenly in contact with a lot of wildlife species in

And so this creates an environment where viruses can spill over.

Bats may be the hosts to these viruses, but we can’t forget the crucial role that they

play in regulating insect populations and as important pollinators, with many plants

depending on them for their survival and propagation.

Some of your favorite fruits like mangos, bananas, or guava wouldn’t exist if bats

I really hope people don't start getting a more negative view of bats, but just because

they're unlucky enough to carry some of these viruses.

Remember, our relationship with wildlife is what allows those viruses to get in.

So let's think about that and change our relationship with wildlife.

If you want to learn more about COVID-19, check out our video here.

And if there's another aspect of COVID-19 that you want to see us cover, let us know

Make sure to subscribe to Seeker for all your viral news.

Thanks for watching, and I’ll see you next time.