Data from: A pace and shape perspective on fertility

1. Aging is ubiquitous to all organisms, but aging does not always mean
senescence. Counter to most evolutionary theories of aging, patterns of
mortality and reproduction may remain unchanged or improve with age, as
well as deteriorate. Describing this diversity presents a challenge to
eco-evolutionary demography. The pace-shape framework of mortality tackled
this challenge to qualify and quantify orthogonal components of aging
patterns in mortality. Here we extend this framework to fertility. 2.
Analogous to the logic of the mortality framework, we define a
perspective, a framework and novel methods for the pace and shape of
fertility. These distinguish between orthogonal components of time scale
(pace) and distribution (shape) of reproduction over adult lifespan. 3.
Our pace and shape framework mirrors that of mortality, through a shift of
perspective from the mother giving birth, to the offspring being born. Our
new measures overcome many problems associated with measuring natural
fertility trajectories, have both a clear biological and mathematical
interpretation, can be intuitively visualised, and satisfy and extend
important conditions of the pace-shape paradigm. 4. A comprehensive
framework of fertility pace-shape facilitates ecological and evolutionary
research addressing interacations and trade-offs between components of
birth and death patterns, across the whole tree of life. The burgeoning
emergence of large comparative demographic data sources across wide
environmental, geographical, temporal and phylogenetic ranges, combined
with pace-shape measures, opens the door to comparative analyses of aging
which were never possible before.