FACTORS THAT PROMOTE AND PREVENT PREPARATION FOR FUTURE CARE NEEDS: PERCEPTIONS OF OLDER CANADIAN,GERMAN, AND U.S. WOMEN

The risk of needing help with household tasks or of requiring care in old age increases. Using semi-structured, qualitative interviews, beliefs about the usefulness versus uselessness of planning ahead for future care needs (FCN) were investigated in 23 East German, 10 U.S., and 10 Canadian elderly-community dwelling women ( S 65 years). Primary reasons in favor of planning for FCN were: gaining a feeling of security regarding the future, avoiding being a burden to potential helpers, and coping with one's present health conditions. Factors that prevent planning for FCN were: the difficulty foreseeing FCN, the lack of resources to plan, and low levels of perceived vulnerability. The women dealt with the contradictions between these factors that promote and prevent preparation by making general plans which could be adapted in the case of needing help by developing alternative plans or by avoidance of thinking about possible future health crises.     

Clades reach highest morphological disparity early in their evolution

There are few putative macroevolutionary trends or rules that withstand scrutiny. Here, we test and verify the purported tendency for animal clades to reach their maximum morphological variety relatively early in their evolutionary histories (early high disparity). We present a meta-analysis of 98 metazoan clades radiating throughout the Phanerozoic. The disparity profiles of groups through time are summarized in terms of their center of gravity (CG), with values above and below 0.50 indicating top- and bottom-heaviness, respectively. Clades that terminate at one of the “big five” mass extinction events tend to have truncated trajectories, with a significantly top-heavy CG distribution overall. The remaining 63 clades show the opposite tendency, with a significantly bottom-heavy mean CG (relatively early high disparity). Resampling tests are used to identify groups with a CG significantly above or below 0.50; clades not terminating at a mass extinction are three times more likely to be significantly bottom-heavy than top-heavy. Overall, there is no clear temporal trend in disparity profile shapes from the Cambrian to the Recent, and early high disparity is the predominant pattern throughout the Phanerozoic. Our results do not allow us to distinguish between ecological and developmental explanations for this phenomenon. To the extent that ecology has a role, however, the paucity of bottom-heavy clades radiating in the immediate wake of mass extinctions suggests that early high disparity more probably results from the evolution of key apomorphies at the base of clades rather than from physical drivers or catastrophic ecospace clearing.