Biology subjects

Newman, S. J.

Publications and source records attributed to Newman, S. J..

3 recordsLinked to original sources

bioRxiv2018

Late-life mortality plateaus through error, not evolution

This study highlights how the mortality plateau in Barbi et al. [1] can be generated by low frequency, randomly distributed age misreporting errors. Furthermore, sensitivity of the late-life mortality plateau in Barbi et al. [1] to the particular age range selected for regression is illustrated. Collectively, the simulation of age misreporting errors in late-life human mortality data and a less specific model choice than that of Barbi et al. [1] highlight a clear alternative hypothesis to the cessation of ageing.

evolutionary biology↗

bioRxiv2017

Global patterns of human ageing

Ageing is a common, but not universal1-3, degradation of biological systems. Ageing in human populations is marked by a highly constrained, log-linear acceleration of the probability of mortality with age4. This acceleration determines the onset and duration of human morbidity5 and the upper limits of human life. Recent studies have revealed remarkable taxonomic diversity in mortality-derived ageing rates1,3. However, the extent of intraspecific variation in ageing rates is assumed to be negligible2. Here we show the considerable diversity of human ageing rates, across 81,000 population-specific longitudinal measures of the ageing rate derived from 330 billion life-years of mortality data. These data reveal remarkable flexibility and unexpected trends in the pattern of human ageing. Populations with lo ...

developmental biology↗

bioRxiv2017

The dynamic upper limit of human lifespan

We respond to claims by Dong et al. that human lifespan is limited below 125 years. Using the log-linear increase in mortality rates with age to predict the upper limits of human survival we find, in contrast to Dong et al., that the limit to human lifespan is historically flexible and increasing. This discrepancy can be explained by Dong et al.s use of data with variable sample sizes, age-biased rounding errors, and log(0) instead of log(1) values in linear regressions. Addressing these issues eliminates the proposed 125-year upper limit to human lifespan.

physiology↗