Where Do New Viruses Come From?

Summary

Stated Clearly explores the origins of new viruses, like the novel coronavirus, emphasizing natural evolution from animal viruses as the most likely source. The video explains how viruses, particularly coronaviruses, can mutate and 'spillover' into new hosts, leading to potential epidemics. It highlights the importance of international cooperation and organizations like WHO in containing outbreaks, and encourages viewers to stay informed for public health.

Takeaways

• 🌐 The novel coronavirus (COVID-19) originated in late 2019 in China and spread globally via international air travel.
• 🔬 The virus's origin is speculated to be from a natural mutation of an animal virus, not a genetically modified weapon or an escaped lab specimen.
• 🦠 Viruses are tiny infectious agents that consist of a small collection of genes enclosed in a protein coat and sometimes a lipid membrane.
• 🐦 Coronaviruses infect a wide range of animals, with most being mild and causing common colds in humans.
• 🔄 Evolution through mutation, reassortment, and recombination can enable viruses to infect new host species, a process known as 'spillover infection'.
• 🌿 Spillover events are rare but can lead to significant outbreaks if the virus adapts well to the new host, as seen with SARS originating from bats to civets to humans.
• 🌏 The likelihood of a virus successfully infecting a new species is low, but the high frequency of human-animal interactions increases the chances of such events.
• ✈️ Global connectivity, especially through international flights, can rapidly spread local outbreaks to a worldwide scale.
• 🛡 International cooperation and organizations like the World Health Organization play crucial roles in containing and preventing pandemics.
• 🌟 The video emphasizes the importance of staying informed through reliable sources like the WHO and encourages international unity to combat global health threats.

Q & A

What is the primary source of funding for Stated Clearly?

Stated Clearly is primarily funded by its viewers on Patreon.

What is the main topic of the video 'Where do new viruses come from?'

The main topic of the video is the origin of new viruses, specifically focusing on the novel coronavirus that started in late 2019.

What are some of the speculations about the origin of the coronavirus mentioned in the script?

Some speculations mentioned include the virus being a genetically modified weapon or an escaped lab specimen.

What is the most likely natural explanation for the origin of the new coronavirus according to the script?

The most likely natural explanation is that the new coronavirus evolved from an older animal-infecting coronavirus.

What is the general structure of a virus as described in the script?

A virus generally consists of a small collection of genes enclosed in a protective coating of protein and sometimes a lipid membrane.

How do viruses typically infect living cells?

Viruses infect living cells by getting their genes inside the cell, which then starts reading the viral genes and building copies of the virus instead of performing its normal tasks.

What is the significance of the 'corona' in coronaviruses?

The 'corona' refers to the unusually large crown-like spikes sticking out of their membranes, which are selectively sticky and help the virus attach to specific molecules on the outsides of animal cells.

How can a virus overcome the inability to infect a new host species?

A virus can overcome the inability to infect a new host species through mutations that change the shape of its spikes, allowing it to attach to new host cells.

What is a 'spillover infection'?

A 'spillover infection' is when a virus that usually infects animals manages to infect humans, often due to a mutation that allows it to attach to human cells.

What role does natural selection play in the evolution of viruses?

Natural selection promotes any new mutations that help a virus better spread and reproduce in a new host population, leading to the accumulation of positive mutations over multiple generations.

Why are international groups like the World Health Organization important in controlling the spread of new viruses?

International groups like the World Health Organization are important because they help contain outbreaks and prevent catastrophes through international cooperation.

Outlines

00:00

🌐 Origin of New Viruses

The paragraph discusses the origins of new viruses, using the novel coronavirus as an example. It mentions that the virus started in China and spread internationally due to air travel. It dismisses the theory that the virus is a genetically modified weapon, and instead suggests a more natural explanation. Viruses are described as tiny infectious agents with genetic material enclosed in a protein coat. Coronaviruses are highlighted as a large family of viruses that infect animal cells, with some causing mild illnesses like the common cold. The paragraph explains how viruses evolve and potentially 'spill over' from animals to humans through mutations, which can alter the virus's ability to attach to host cells.

05:00

🔬 Evolution and Spread of Viruses

This paragraph delves into the process of viral evolution and spillover infections. It explains that while most spillover events lead to dead ends, some viruses can adapt and evolve through natural selection, leading to new epidemics. The paragraph provides historical examples of spillover events, such as SARS originating from bats to civets and then to humans, and HIV from chimps to humans. It also mentions other viruses like swine flu and the 1918 Spanish flu, which may have originated from pigs and chickens, respectively. The paragraph emphasizes the role of international cooperation and organizations like the World Health Organization in containing outbreaks. It concludes by stating that new viruses often evolve from old ones and that stopping their spread requires global collaboration.

Keywords

💡Coronavirus

Coronavirus refers to a large family of viruses that cause illnesses ranging from the common cold to more severe diseases. In the context of the video, the novel coronavirus (COVID-19) is discussed as an example of how new viruses can emerge. The script explains that these viruses are named for the 'crown-like' spikes on their surface, which enable them to attach to and infect host cells. The video suggests that the COVID-19 virus may have evolved from an animal coronavirus, highlighting the potential for spillover infections.

💡Spillover Infection

A spillover infection is a phenomenon where a virus jumps from its natural host species to a new one, often facilitated by mutations that allow it to bind to new host cell receptors. The video uses the term to explain how viruses like COVID-19 might have originated from animals and then adapted to infect humans. It emphasizes that while such events are rare, they can lead to significant outbreaks if the virus becomes efficient at infecting the new host.

💡Mutation

Mutation is defined as a change in the genetic sequence of a virus, which can occur during replication due to errors or through processes like reassortment and recombination. The video highlights that while most mutations render a virus non-viable, occasionally a mutation might allow a virus to infect a new host species, as potentially happened with the COVID-19 virus.

💡Evolution

Evolution, as discussed in the video, is the process by which species change over time through genetic variation and natural selection. The script suggests that new viruses, like the COVID-19 virus, often evolve from older viruses through a series of mutations and adaptations, which can be facilitated by processes like spillover infections.

💡Natural Selection

Natural selection is the mechanism by which organisms better adapted to their environment tend to survive and produce more offspring. In the context of the video, it is explained that if a virus can infect a new host and survive long enough, natural selection may favor mutations that help it spread and reproduce more effectively within that new host population.

💡Pandemic

A pandemic refers to an outbreak of a disease that occurs over a wide geographic area and affects an exceptionally high proportion of the population. The video implies that a new virus, after evolving and adapting to a new host through spillover and mutation, can potentially lead to a pandemic if it becomes highly transmissible and virulent among humans.

💡Host Species

A host species is an organism that provides a suitable environment for a parasite, such as a virus, to live and reproduce. The video discusses how viruses typically have specific host species, and a change in the virus's ability to infect a new host species, like humans, can lead to spillover infections and potentially pandemics.

💡Genetically Modified Virus

A genetically modified virus is one that has been altered in the laboratory to have different characteristics from the original virus. The video addresses speculation about the COVID-19 virus possibly being a genetically modified virus, but concludes that such claims require extraordinary evidence and are currently unlikely.

💡International Air Travel

International air travel is a mode of transportation that connects different parts of the world, allowing people to move across countries and continents. The video points out that international air travel has played a significant role in the rapid spread of the COVID-19 virus from its origin to other countries, highlighting the interconnectedness of global health.

💡World Health Organization (WHO)

The World Health Organization is a specialized agency of the United Nations responsible for international public health. In the video, WHO is mentioned as a key international group that works to contain outbreaks and provide accurate information on health risks, emphasizing the importance of global cooperation in managing pandemics.

💡Viral Reproduction

Viral reproduction is the process by which viruses replicate themselves by hijacking the machinery of a host cell. The video explains that once a virus enters a host cell, it uses the cell's resources to make copies of itself, often disrupting the cell's normal functions. This process is central to how viruses spread within a host and from host to host.

Highlights

Stated Clearly explores the origins of new viruses, specifically the novel coronavirus.

The coronavirus began making people ill in China in late 2019 and spread internationally.

Speculations about the virus's origin range from a genetically modified weapon to an escaped lab specimen.

A more natural explanation suggests the virus evolved from an older animal-infecting coronavirus.

Viruses are among the smallest entities that can make you sick by infecting and reproducing inside you.

Coronaviruses are a large family of viruses that infect animal cells, with most being mild.

The 'corona' refers to the virus's crown-like spikes, which are selectively sticky.

Evolution can sometimes help a virus overcome host specificity through mutations.

Mutations can lead to 'spillover infections' where a virus infects a new host species.

Early spillover events often result in the virus going extinct after infecting just a few people.

Natural selection can promote mutations that help a virus better spread in a new host population.

Genetic evidence suggests that slowly evolving spillovers cause almost every major outbreak.

The SARS virus is an example of a coronavirus that spilled over from bats to civets and then to humans.

Coronaviruses are not the only animal viruses capable of adapting to new hosts; HIV and swine flu are other examples.

The new coronavirus might be a result of normal evolution, with similar viruses found in bats and pangolins.

The chance of a virus evolving to infect a new species is low, but opportunities are abundant due to human-animal interactions.

International cooperation is crucial for containing outbreaks and preventing catastrophes.

The World Health Organization and various centers for Disease Control play key roles in containing outbreaks.

Jon Perry summarizes that new viruses mostly evolve from old ones, and stopping their spread requires international cooperation.

Transcripts

Stated Clearly is funded by our viewers on patreon.com/statedclearly

Stated Clearly presents: Where do new viruses come from? If you've been

watching the news you've probably heard of the novel or new coronavirus which,

starting in late 2019, began making people ill in China. International air

travel has since allowed it to spread person-to-person to new countries. As

government's begin to issue travel restrictions and even quarantines

speculations about the origin of the virus began to spread online. Some claim

that the virus might be a genetically modified weapon but extraordinary claims

require extraordinary evidence. This claim currently seems highly

unlikely. Others suggest that the virus may be an escaped lab specimen. This

actually is possible, viruses have escaped from research labs in the past,

but as of the time that I'm recording this voice-over, investigations into this

idea have not yet reached any solid conclusions. Could there be another more

natural explanation for the origin of the virus? The answer is yes CPVOD-19

the new human-infecting coronavirus, may have simply evolved from an older animal-infecting

coronavirus. To understand how this may have happened let's first take

a look at viruses in general. What are viruses? Of the many things that can make

you sick by infecting and reproducing inside you, viruses are among the

smallest. If we resize this drawing to a more realistic scale you see that

hundreds of viruses can fit inside a single bacterial cell. That's how tiny

they are. Thousands of different viral species have been studied and described

by scientists so far, millions more likely exist. They come in many forms but

all species consists of a small collection of genes (stretches of either

DNA or RNA that carry information for making more copies of the virus) and

those genes are enclosed in a protective coating of protein and sometimes a lipid

membrane. All known viruses are parasitic but most are

not parasitic to humans. Instead some only target plant cells others only

infect bacteria and so on. A virus reproduces by getting its genes into a

living cell. Different viruses do this in different ways but once inside, the cell

acts as if the viral genes were its own genes. It begins reading them and

building copies of the virus instead of performing its normal tasks. Coronaviruses

are a huge family of virus species that infect animal cells. Some

infect chickens, others infect pigs, some infect humans but most of them are

extremely mild. They simply give you the common cold. "Corona" means crown and

refers to the unusually large crown like spikes sticking out of their membranes.

These protein spikes are selectively sticky, sort of like velcro.

They don't attach to most objects but are extremely sticky when they bump into

specific molecules found on the outsides of animal cells. Once held firmly in

place, the corona virus waits until swallowed by the cell. It then begins to

reproduce at the cells expense. Different animal species have different types of

molecules on the outsides of their cells. Because of this, bird infecting corona

viruses usually can't infect humans, their "Velcro" doesn't hold strong enough

to our cells. Unfortunately the natural process of

evolution can sometimes help a virus overcome this problem. When virus genes

are being copied during reproduction, mutations can occur. These are either due

to simple copying errors, or processes called reassortment and recombination.

These happen when two or more viruses infect a single cell. In most cases

mutations that change the shape of viral spikes render the virus useless. There

velcro no longer sticks to any host cells. On rare occasions, however, a chance

mutation will just happen to allow a virus to attach to a new host species. If

the modified virus is then lucky enough to encounter that new host species,

infection can occur. We call this a "spillover infection". The virus has

spilled over into a new type of host. Early on during a spillover event the

virus usually isn't very good at infecting its new host. It's velcro is

not a perfect match and many other challenges might slow the virus down.

Oftentimes the mutations that let it infect the new host also make it worse

at infecting its original host. Because of this, many spillover viruses go

extinct after infecting just one or two people,

they're usually dead ends. That said if the virus can survive and reproduce just

long enough, natural selection will promote any new mutations that help it

better spread and reproduce in the new host population. Positive mutations

accumulate over multiple generations, negative mutations are discarded until...

BAM! A new epidemic is being screamed about on the news. Though it may seem to

us that these new viruses just sort of pop into existence overnight, scientists

now know there is a long slow burn before each explosion. Genetic evidence

tells us that slowly evolving spill overs have been the cause of almost

every major outbreak known in history. In the early 2000s, a coronavirus that used

to only infect bats, appears to have spilled over into civets. There it

mutated even further and spilled over into humans. We called it the SARS virus

because it causes Severe Acute Respiratory Syndrome. It spread

internationally from person to person and several scientists were infected in

the lab. By the time the virus was contained, over 8,000 people had been

infected, over 700 died. A coronavirus from camels also recently spilled over

to humans causing even more deaths. Coronaviruses are not the only types of

animal viruses that can adapt to new hosts. HIV spilled over from chimps, most

likely when someone cut themselves while preparing chimp meat for dinner.

The swine flu came partly from pigs but we think it actually

evolved through a recombination with a pig virus and a bird virus. The 1918

Spanish flu, the big one that devastated populations all around the world, may

have spilled over from chickens! While the evidence is not yet conclusive, the new

coronavirus might just be one more example of normal evolution. A very

similar virus has been found in bats and another was recently discovered in

pangolins. These animals are endangered, they're protected, but they're often used

illegally for food, rituals, and alternative medicine in the region where

COVID-19 first broke out. Now, there are serious people checking to make sure

that the virus did not come from a lab, either by accident or on purpose. After all,

the technology to genetically modified viruses really does exist, but

it's important to understand that the normal process of descent with

modification acted upon by natural selection really does produce new

viruses. It happens naturally. The chance of a virus evolving to successfully

infect a new species is extremely low but there are over seven and a half

billion people on this planet, most of us interact with animals on a

daily basis. We keep them as pets, we eat them as food. This means that as unlikely

as spillover infections might be, there are billions of opportunities for one to

take hold every single day. Add this the fact that the entire world is now

connected through international flights, and you realize that what happens in

Vegas doesn't actually stay in Vegas, at least not the way that it used to.

Luckily we have international groups like the World Health Organization and

various centers for Disease Control to help contain outbreaks when they happen.

With international cooperation we have prevented many catastrophes in the past

and we will prevent many more in the future so long as our species continues

to work together. So in summary, where do new viruses come from?

In most cases, new viruses evolve from old viruses. Stopping the spread of

new viruses requires international cooperation. For up-to-date, accurate

information on the risks, visit the World Health Organization website at WHO.INT

I am Jon Perry and that is the novel coronavirus, Stated Clearly.

This episode of Stated Clearly was funded by our viewers on patreon.com/statedclearly

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consider contributing there as well. Aside from helping me out you will also

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stateclearly.com So long for now, stay curious!

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