6 ms·

Covid killed a lot of people even though we have at least four other coronaviruses running around causing common cold, and most of the victims had some banal co

Covid killed a lot of people even though we have at least four other coronaviruses running around causing common cold, and most of the victims had some banal coronavirus infection before. The plague bacteria of 550 AD was probably not completely identical to the one in 1350 AD either.

vfclists 4y ago
Covid killed a lot "old people", people well past reproductive age.
- Maursault 4y ago
  Only women lose their ability to reproduce past a certain biological age (as opposed to chronological age), and I think you simply mean "those that didn't have children," of any age. But that is how natural selection works, random mutation during sexual reproduction in response to environmental pressure allowing differential survival and reproduction of individuals due to differences in inherited phenotypic traits. Those that died with or without children were not selected for survival as they usually would not have mutated beneficially after they were already conceived. We call that cancer.
Maursault 4y ago
> The plague bacteria of 550 AD was probably not completely identical to the one in 1350 AD either. Both plagues were caused by the same bacteria, Yersinia pestis. I don't see how being "completely identical" would matter, only that it was the same species of bacteria.
- inglor_cz 4y ago
  Yes, it matters. Different strains of the same species of bacteria can have different virulence in human (or animal) hosts.
  - Maursault 4y ago
    Different strains of the same bacteria species can produce different immune responses, but if the species is pathogenic to humans, all its strains will also be considered the same pathogen. The Plague of Justinian and the Black Death were both known to be virulent in that they were both rapid, severe, and destructive, but virulence is not an objectively measurable quality.

6 ms·

Covid killed a lot of people even though we have at least four other coronaviruses running around causing common cold, and most of the victims had some banal co

by inglor_cz 4y ago

vfclists 4y ago
Covid killed a lot "old people", people well past reproductive age.
- Maursault 4y ago
  Only women lose their ability to reproduce past a certain biological age (as opposed to chronological age), and I think you simply mean "those that didn't have children," of any age. But that is how natural selection works, random mutation during sexual reproduction in response to environmental pressure allowing differential survival and reproduction of individuals due to differences in inherited phenotypic traits. Those that died with or without children were not selected for survival as they usually would not have mutated beneficially after they were already conceived. We call that cancer.
Maursault 4y ago
> The plague bacteria of 550 AD was probably not completely identical to the one in 1350 AD either. Both plagues were caused by the same bacteria, Yersinia pestis. I don't see how being "completely identical" would matter, only that it was the same species of bacteria.
- inglor_cz 4y ago
  Yes, it matters. Different strains of the same species of bacteria can have different virulence in human (or animal) hosts.
  - Maursault 4y ago
    Different strains of the same bacteria species can produce different immune responses, but if the species is pathogenic to humans, all its strains will also be considered the same pathogen. The Plague of Justinian and the Black Death were both known to be virulent in that they were both rapid, severe, and destructive, but virulence is not an objectively measurable quality.