As we try to make sense of how a change in sodium channels in Neanderthals may have impacted pain sensitivity in modern humans, another recently illuminated cellular-level alteration in our ancestors sheds light on another aspect of our immunity: "How an ancient microbial arms race remodeled human cells" (Gibbons, Science. 31 Jul 2020, 369(6503): 491–492. doi: 10.1126/science.369.6503.491). PAYWALL (Contact: email@example.com for access)
Our ancestors totally remodeled their cell surfaces in response to some past pathogen(s) over 2 million years ago. The dramatic make-over then required a major readjustment of the innate immune "machinery for sensing self." This readjustment mostly took place before Neanderthals and "anatomically-modern" humans diverged over .5 million years ago. Many human-specific pathogens have since adapted to recognize the human-specific cell surfaces to manipulate host immunity and to invade and infect.
Dive deeper into the details: "Multiple Genomic Events Altering Hominin SIGLEC Biology and Innate Immunity Predated the Common Ancestor of Humans and Archaic Hominins." (Khan et al. Genome Biol. Evol. 12(7):1040–1050. doi:10.1093/gbe/evaa125. Advance Access publication, 18 June 2020). OPEN ACCESS
TL;DR: "Are there human-specific diseases?" (Nissi Varki, 21 May 2020. "Impact of Infectious Disease on Humans and Our Origins," CARTA Symposium. OPEN ACCESS
08/01/2020: "Humans Might Be So Sickly Because We Evolved to Avoid a Single Devastating Disease." (McCrae, Science Alert: Health, 01 Aug 2020). OPEN ACCESS
Learn more about these UC San Diego scientists and the full spectrum of their research by exploring their CARTA Profiles below: