The shaping of senescence in the wild

Mortality rates of honey bees in the wild

“…In spite of the broad interest in the evolutionary biology of senescence, many basic issues remain unresolved (Williams et al, 2006). Honey bees possess a variety of features that make them an ideal experimental model system for studying life history in natural settings (Dukas, 2008b;Dukas and Visscher, 1994;Schippers et al, 2006).…”

“…It is difficult to predict from theory the pattern of senescence in a given species (Abrams, 1993;Reznick et al, 2004;Williams et al, 2006) and it is not even clear whether wild insects live long enough to exhibit senescence (Kirkwood and Austad, 2000). That is, high mortality rates owing to predation could result in brief life spans and little senescence in wild insects.…”

The Risk of Flawed Inference in Evolutionary Studies When Detectability Is Less than One

“…Gaillard et al (1993) provide further details on the MR protocol. We investigated actuarial senescence patterns (i.e., the age-related increase in mortality rate; Williams et al 2006) in deer by estimating age-specific variation in survival. Actuarial senescence patterns in roe deer are well described using a Gompertz curve (Gaillard et al 2004), which assumes that the mortality hazard is exponentially related to age x m(x) as , where A and b are usually considered m(x) p A exp (bx) to be intercept and slope, respectively (e.g., Service 2004).…”

“…Two objectives that have recently received a growing level of attention but that suffer from this problem of nonperfect detectability are (i) demonstrating microevolution within a population where selection on an evolving trait is measured Kingsolver et al 2001) and (ii) investigating survival senescence and its evolution in the wild (Bronikowski and Promislow 2005;Williams et al 2006). Here, we use two long-term data sets to illustrate the risk of flawed inference in these two types of evolutionary studies when detectability is less than unity.…”

Diet mediates the relationship between longevity and reproduction in mammals

“…In some species, high levels of extrinsic mortality due to disease, predation, or abiotic pressures may result in low levels of selection for longevity-enhancing traits, which would not have a chance to be expressed in nature (Williams 1957;Williams et al 2006;Ricklefs 2010). This extrinsic mortality hypothesis has been used to explain the significantly higher lifespans of flying or arboreal animals, especially birds and bats, which may have lower mortality due to predation compared to similarly sized non-flying animals (Austad and Fischer 1991;Wilkinson and South 2002;Shattuck and Williams 2010;Wasser and Sherman 2010).…”