原標(biāo)題：科學(xué)家們?nèi)绾文艽_認(rèn)新冠病毒并非實(shí)驗(yàn)室產(chǎn)物,？

從疫情爆發(fā)至今，雖然世界各地的科學(xué)家們都反復(fù)強(qiáng)調(diào)這種初次被發(fā)現(xiàn)的病毒來源于自然界，但是“新冠病毒是實(shí)驗(yàn)室產(chǎn)物”的陰謀論依然無休無止,。

那么,，科學(xué)家們到底是如何知道病毒并非來自實(shí)驗(yàn)室,，而是起源于某種動(dòng)物的呢,？

威斯敏斯特大學(xué)一位寄生蟲學(xué)與醫(yī)學(xué)微生物學(xué)講師，Polly Hayes,，本周發(fā)表的一篇文章,，引用多項(xiàng)研究對(duì)這個(gè)問題作出了解釋。

The conspiracy theory that the novel coronavirus was created in a lab has been circulating since the beginning of the COVID-19 outbreak,， although scientists from different countries have refuted it over and again and stressed the natural origin of the virus,。

So how exactly do scientists know the virus SARS-CoV-2 originated from an animal， most likely a bat,， and was not lab-made,？

Polly Hayes， a lecturer in Parasitology and Medical Microbiology at the University of Westminster,， explained the question in an article published on British website The Conversation earlier this week,， citing multiple studies。

基因物質(zhì)里并沒有人為操縱的跡象

No signs of manipulation in the genetic material of SARS-CoV-2

Hayes指出,，如果病毒來自實(shí)驗(yàn)室里的基因工程,，那么它的基因序列數(shù)據(jù)一定存在人為操縱的跡象。

但是,，新冠病毒的基因序列已被全世界的科學(xué)家公開分享了數(shù)千次,，而且從未發(fā)現(xiàn)過這樣的證據(jù)。

Hayes pointed out that if the virus had been genetically engineered in a lab,， there would be signs of manipulation in the genome data,。

This would include evidence of an existing viral sequence as the backbone for the new virus， and obvious targeted inserted （or deleted） genetic elements,。

But the genetic sequence of SARS-CoV-2 has been publicly shared thousands of times by scientists all over the world,， and no such evidence has ever been found。

She added that it is very unlikely that any techniques used to genetically engineer the virus would not leave a genetic signature， like specific identifiable pieces of DNA code,。

從野生型的冠狀病毒進(jìn)化而來

SARS-CoV-2 evolved from a previous wild coronavirus

新冠病毒的基因序列與其他在蝙蝠和穿山甲身上發(fā)現(xiàn)的冠狀病毒基因序列相似,，不止如此，這些基因序列之間的差異顯示了冠狀病毒進(jìn)化的自然模式,。

The genome of SARS-CoV-2 is similar to that of other bat coronaviruses， as well as those of pangolins,， all of which have a similar overall genomic architecture,。

What‘s more， differences between the genomes of these coronaviruses show natural patterns typical of coronavirus evolution,， which suggests that SARS-CoV-2 evolved from a previous wild coronavirus,。

與武漢病毒研究所發(fā)現(xiàn)的蝙蝠病毒在進(jìn)化上有顯著差異

SARS-CoV-2 and a bat virus in Wuhan lab significantly different in evolutionary terms 

一些媒體報(bào)道說，新冠病毒可能來自武漢病毒研究所的研究人員發(fā)現(xiàn)的另一種已知的蝙蝠病毒（RaTG13）,，因?yàn)檫@兩種病毒的基因序列相似性高達(dá)96%,。但Hayes澄清說，從進(jìn)化的角度來看,，它們實(shí)際上有顯著差異,。

Some media reports have said that SARS-CoV-2 may come from another known bat virus （RaTG13） found by researchers at the Wuhan Institute of Virology， since the genomes of the two viruses were 96 percent similar to one another,。

But Hayes clarified that in evolutionary terms,， this actually makes them significantly different and the two have been shown to share a common ancestor。 That means RaGT13 is not an ancestor of SARS-CoV-2,。 

與其他冠狀病毒有相似特性

SARS-CoV-2 shared similar features with related coronaviruses

新型冠狀病毒感染人體細(xì)胞的關(guān)鍵在于冠狀病毒的刺突糖蛋白與人體ACE2蛋白的結(jié)合,，但是，其他類似的冠狀病毒都具有相似的特征,。而新冠病毒的刺突糖蛋白與人體細(xì)胞的結(jié)合效率之高,，通過基因工程無法達(dá)到，只有自然選擇才能實(shí)現(xiàn),。

One of the key features that makes SARS-CoV-2 different from the other coronaviruses is a particular “spike” protein that binds well with another protein on the outside of human cells called ACE2,。 This enables the virus to hook into and infect a variety of human cells。

However,， other related coronaviruses do have similar features,， providing evidence that they have evolved naturally rather than being artificially added in a lab。 

大多數(shù)傳染病和所有已知的冠狀病毒的來源是動(dòng)物

The majority of infectious diseases and all known coronaviruses have animal origins

據(jù)估計(jì),，人類已知的傳染病中有60%來源于動(dòng)物,，在所有新發(fā)或再發(fā)疾病中這個(gè)比例達(dá)到75%。

新冠病毒是人類發(fā)現(xiàn)的七種冠狀病毒中最新的一種,，而它們?nèi)縼碜则?，小鼠或其他家畜?/p>

An estimated 60 percent of known infectious diseases and 75 percent of all new， emerging， or re-emerging diseases in humans have animal origins,。

SARS-CoV-2 is the newest of seven coronaviruses found in humans,， all of which came from animals， either from bats,， mice or domestic animals,。

The mixing or “recombination” of distinct coronavirus genomes in nature is one of the mechanisms that bring about novel coronaviruses。 There is now further evidence that this process could be involved in the generation of SARS-CoV-2,。

最有可能來自蝙蝠

SARS-CoV-2 most likely originated from bats

實(shí)際上,，新冠病毒最有可能是由一種病毒變異體進(jìn)化而來，該變異體無法長(zhǎng)時(shí)間存活或潛伏于蝙蝠體內(nèi),。

巧合的是,，它進(jìn)化出了入侵人類細(xì)胞的能力，然后可能是通過中間的動(dòng)物宿主偶然獲得了進(jìn)入人類社會(huì)的途徑,，得以繁衍傳播,。

In fact， SARS-CoV-2 most likely evolved from a viral variant that couldn‘t survive for a long period of time or that persists at low levels in bats,。

Coincidentally,， it evolved the ability to invade human cells and accidentally found its way into humans， possibly by means of an intermediate animal host,， where it then thrived,。

Or an initially harmless form of the virus might have jumped directly into humans and then evolved to become harmful as it passed between people。

Bats were also the source of the viruses causing Ebola,， rabies,， Nipah and Hendra virus infections， Marburg virus disease,， and strains of Influenza A virus,。