[jxramos]

Can someone substantiate this idea that it's improbable for a virus to surmount these two evolutionary obstacles highlighted below? I'll copy the quote for the idea I've seen circulating, the bold part is the idea I'd like to hear challenged and would like to learn more about what its foundation is predicated upon.

    For ultimately, in order to create a human pandemic, an animal virus has to accomplish **two very difficult things**. First, it has to successfully infect a person, and then it needs to jump from one person to the next rapidly enough to get ahead of the rate at which sufferers recover or die. SARS2 is a master of this trick, but the closest wild relatives seem to be neutralised, with spike proteins built to invade horseshoe bat cells, not human cells. To trigger a pandemic in people they need substantial evolutionary retooling.

[refenestrator]

Sars and bird flu both did it in that part of the world quite recently. It's not like the phenomenon is unheard of.

Maybe it's unlikely but when you also have a billion people in third world conditions.. it's not that unlikely after all.

[Zenst]

I like to think of such unlikely things in the context of winning the lottery, that I find gives a perspective based upon however large the odds are - somebody does win in the end.

I didn't see any numbers in the article to give some weight to any probability word usage.

[ksaj]

If you must think of it as a lottery, there are millions of bats, and millions of people in this draw. The probability isn't so remote.

[heavyset_go]

60% of infectious diseases in humans are zoonotic[1], meaning they originated in animals.

[1] https://www.cdc.gov/onehealth/basics/zoonotic-diseases.html

[monocasa]

It's rare in the global sense, but really nasty infections are sort of known for jumping from another mammalian species. AIDS, original SARS, Ebola, etc. all fit that pattern.

[Zenst]

When it comes to odds in mammalian species, you can't but help be reminded of https://en.wikipedia.org/wiki/Infinite_monkey_theorem

[apalmer]

this statement is true but meaningless...

Majority of pandemics in history are a result of this rare in absolute terms occurrence.

In general diseases that are already highly evolved for their host, mostly innocuous... everyone gets the common cold like 2 times a year, 80% of people have herpes, etc... in most cases the pandemics are caused by diseases that have crossed the infection boundary but arent evolved enough to appropriate limit themselves, this commonly occurs because the disease recently jumped from one host to another..