3 ms·

That claim seemingly stems from a misinterpretation of the paper’s discussion, since no mechanisms are proposed or mentioned there: > The evolution of the vert

That claim seemingly stems from a misinterpretation of the paper’s discussion, since no mechanisms are proposed or mentioned there: > The evolution of the vertebrate immune system occurred in geographically limited populations. Before machine-mediated transportation— trains, planes, boats and cars—individuals were likely to be exposed to the majority of pathogens in their local geography by the time of reproductive age. As T and B memory/stem cells can survive an individual’s lifetime[60,61], they should be sufficient to provide adaptive immune memory to all local pathogens. Thus, the generation of new T and B lymphocytes in later life was probably no longer advantageous, whereas the production of short-lived myeloid cells would remain important for acute innate responses, even in later life.

bigbillheck 3y ago
> ...vertebrate...Before machine-mediated transportation— trains, planes, boats and cars—individuals were likely to be exposed to the majority of pathogens in their local geography by the time of reproductive age This hypothesis would be testable by looking at migrating animals, such as gray whales or arctic terns.
pazimzadeh 3y ago
I'm not sure I understand what biogeography has to do with their point which seems to mainly be about the passage of time. Also, I thought the adaptive immune system came about in marine vertebrates? Doesn't water mix things up pretty well? Re-evaluation of the immunological Big Bang https://pubmed.ncbi.nlm.nih.gov/25517375/ https://pubmed.ncbi.nlm.nih.gov/25517375/ A cold-blooded view of adaptive immunity https://pubmed.ncbi.nlm.nih.gov/29556016/ https://pubmed.ncbi.nlm.nih.gov/29556016/
- flobosg 3y ago
  > I'm not sure I understand what biogeography has to do with their point which seems to mainly be about the passage of time. Individuals in different biogeographical niches can have distinct “passages of time” in their immune systems, depending on their exposure to endemic pathogens. > Doesn't water mix things up pretty well? So does air, but you don’t see a homogeneous distribution of airborne pathogens around the world :) By the way, thanks for those papers, they reminded me of single-domain antibodies (or “nanobodies”), which appear to have evolved independently in cartilaginous fish and camelids: https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1001120 https://journals.plos.org/plosbiology/article?id=10.1371/jou...

bigbillheck 3y ago

> ...vertebrate...Before machine-mediated transportation— trains, planes, boats and cars—individuals were likely to be exposed to the majority of pathogens in their local geography by the time of reproductive age This hypothesis would be testable by looking at migrating animals, such as gray whales or arctic terns.

pazimzadeh 3y ago

I'm not sure I understand what biogeography has to do with their point which seems to mainly be about the passage of time. Also, I thought the adaptive immune system came about in marine vertebrates? Doesn't water mix things up pretty well? Re-evaluation of the immunological Big Bang https://pubmed.ncbi.nlm.nih.gov/25517375/ https://pubmed.ncbi.nlm.nih.gov/25517375/ A cold-blooded view of adaptive immunity https://pubmed.ncbi.nlm.nih.gov/29556016/ https://pubmed.ncbi.nlm.nih.gov/29556016/

flobosg 3y ago
> I'm not sure I understand what biogeography has to do with their point which seems to mainly be about the passage of time. Individuals in different biogeographical niches can have distinct “passages of time” in their immune systems, depending on their exposure to endemic pathogens. > Doesn't water mix things up pretty well? So does air, but you don’t see a homogeneous distribution of airborne pathogens around the world :) By the way, thanks for those papers, they reminded me of single-domain antibodies (or “nanobodies”), which appear to have evolved independently in cartilaginous fish and camelids: https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1001120 https://journals.plos.org/plosbiology/article?id=10.1371/jou...