How the Black Death shaped human evolution.

[sjastro]

The fourteenth-century bubonic plague pandemic known as the Black Death was caused by the bacterium Yersinia pestis and killed up to half the population in Europe, the Middle East, and North Africa.
The pandemic was more likely to kill those who did not have the genetic variants that protected against infection. People with protective versions of certain genes would be more likely to survive and pass on those variants to future generations.

However, the protection against plague conferred by these variants appears to have come at a cost such as increasing the risk factor for Crohn’s disease. Another protective variant has been associated with an increased risk of two autoimmune diseases.
The Black Death and other past pandemics may have shaped humans’ immune systems in ways both good and bad.

Nature article.
Evolution of immune genes is associated with the Black Death | Nature

 

[SelfSim]

The fourteenth-century bubonic plague pandemic known as the Black Death was caused by the bacterium Yersinia pestis and killed up to half the population in Europe, the Middle East, and North Africa.
The pandemic was more likely to kill those who did not have the genetic variants that protected against infection. People with protective versions of certain genes would be more likely to survive and pass on those variants to future generations.

However, the protection against plague conferred by these variants appears to have come at a cost such as increasing the risk factor for Crohn’s disease. Another protective variant has been associated with an increased risk of two autoimmune diseases.
The Black Death and other past pandemics may have shaped humans’ immune systems in ways both good and bad.

Nature article.
Evolution of immune genes is associated with the Black Death | Nature

So much for the idea that humans represent some kind of imaginary 'pinnacle' of the evolutionary tree of life on Earth ...

 

[Shemjaza]

Given what happened to the native Australians and Americans... I'll take some chronic GI tract issues over borderline extinction in face of plagues.

 

[Bob Crowley]

As far as I know the survivors were still human beings, albeit with a possibly higher chance of surviving the Black Death.

Ditto for bacteria that become resistant to antibiotics - they're still bacteria. They don't go and change phyla, nor do they even begin to move towards a 'more advanced' life form.

In additiion, some of them had the resistance built in before the antibiotic was even invented. I suppose from a Christian perspective pointing out that God has put us under a "curse", it seems He's made sure we can't get rid of these offending bugs as easily as we might wish. The "curse" remains.

 

[sjastro]

As far as I know the survivors were still human beings, albeit with a possibly higher chance of surviving the Black Death.

Ditto for bacteria that become resistant to antibiotics - they're still bacteria. They don't go and change phyla, nor do they even begin to move towards a 'more advanced' life form.

In additiion, some of them had the resistance built in before the antibiotic was even invented. I suppose from a Christian perspective pointing out that God has put us under a "curse", it seems He's made sure we can't get rid of these offending bugs as easily as we might wish. The "curse" remains.

This is about microevolution not macroevolution.

 

[chilehed]

So much for the idea that humans represent some kind of imaginary 'pinnacle' of the evolutionary tree of life on Earth ...

I've never heard anyone espouse such an idea.

 

[Ophiolite]

I've never heard anyone espouse such an idea.

Was that sarcasm? I ask because until the 19th Century that was pretty much standard thinking: the scala naturae, the Great Chain of Being.

 

[chilehed]

Was that sarcasm?

Not at all.

 

[jayem]

The fourteenth-century bubonic plague pandemic known as the Black Death was caused by the bacterium Yersinia pestis and killed up to half the population in Europe, the Middle East, and North Africa.
The pandemic was more likely to kill those who did not have the genetic variants that protected against infection. People with protective versions of certain genes would be more likely to survive and pass on those variants to future generations.

However, the protection against plague conferred by these variants appears to have come at a cost such as increasing the risk factor for Crohn’s disease. Another protective variant has been associated with an increased risk of two autoimmune diseases.
The Black Death and other past pandemics may have shaped humans’ immune systems in ways both good and bad.

Nature article.
Evolution of immune genes is associated with the Black Death | Nature

No doubt that the 14th century Yersinia epidemic had an evolutionary effect. But let's not overlook a very important factor. Which was that younger persons--teens and early 20 and 30 year-olds--died in as high numbers as older persons. Evolution by natural selection is driven by reproductive success. If a disease largely kills older persons, who are past reproductive age, then there is little evolutionary effect. (Covid-19 is an example. About 9 out of 10 deaths are in persons 65 and older.) But evolution occurs when there's a high mortality among those of reproductive age. The survivors will pass whatever genetic traits or alleles protected them from death into subsequent generations. And thus the population evolves.