Aging is a traveling wave
W Zuo, S Jiang, Z Guo, MW Feldman, S Tuljapurkar. 2018. Advancing front of old-age human survival. Proceedings of the National Academy of Sciences. 115(44):11209-11214
We show, for five decades in 20 developed countries, that old-age survival follows an advancing front, like a traveling wave. The front lies between the 25th and 90th percentiles of old-age deaths, advancing with nearly constant long-term shape but annual fluctuations in speed. Our unexpected result has implications for biological hypotheses about human aging and for future mortality change.