Aging is a traveling wave

EVOLUTION AND ECOLOGY
2018
Traveling wave of female

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.