Parasites Benefit Their Hosts — At The Individual Level
Parasites are usually regarded as nasty symbionts that harm their hosts. The articles by Harris and Wickramasinghe and by Hu et al. show that some helminth parasites can actually benefit their hosts by inducing the production of antibacterial agents, in this case the SPRR2A protein. So, perhaps these helminths are not parasites but are some other form of symbiont.
Changing their designation is not merely a trivial argument over definitions. A fundamental puzzle I have been trying to solve is why parasites manage to survive. Why are hosts unable to evolve ways to render parasites extinct? An arms race is the usual answer, but I have a different one.
Parasitism is a property of life.
Life on Earth that is. A great deal of research is being done on trying to find extraterrestrial life. Will parasitism also be a property of that life?
Harris, Nicola ; Wickramasinghe. A helminth-induced antimicrobial protein. Science 2021 November 5; 374(6568): 682-683.
Hu, Zehan ; Zhang Chenlu ; Sifuentes-Dominguez, Luis ; Zarek, Christina M. ; Propheter, Daniel C. ; Kuang, Zheng ; Wang, Yuhhao ; Pendse Mihir ; Ruhn, Kelly A. ; Hassell, Brian ; Behrendt, Cassie L. ; Zhang, Bo ; Raj, Pithvi ; Harris-Tryon, Tamia A.; Reese, Tiffany A. ; Hooper, Lora V.
Small proline-rich protein 2A is a gut bacterialcidal protein deployed during helminth infection. Science 2021 November 5; 374(6568): 710.
Windsor, Donald A. Parasitism as a property of life. Parasites Dominate 2013 September 3; Post #2. parasitesdominate.blogspot.com
Windsor, Donald A. Parasitism on Mars. Parasites Dominate 2015 November 8; Post #10. parasitesdominate.blogspot.com