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Older people are the largest group accessing and using care services within Europe (Eurostat 2015) and are often referred to as a "burden" (Beard and Bloom 2015). Improvements in public health, medical screening, timely treatments, and improved health and social care services in industrialized countries have all contributed to people living longer and healthier lives (Carr and Komp 2011). Average life expectancy is now estimated to be 78 years in developed countries and 68 years in less developed countries, with the gap continually narrowing every year. By 2045-2050, life expectancy is projected to reach 83 years in more developed countries and 75 years in less developed countries (Department of Economic and Social Affairs Population Division 2013). Whilst a defining characteristic of the ageing process may involve increased vulnerability to a decline in health and wellbeing (Kirkwood 2014), novel approaches to wellbeing alongside complex biological, medical, psychosocial, political, and economic factors can influence both individual and group trajectories in later life. Ageing remains an extremely complex field in terms of understanding the relationships between these contributory factors and the transitions that connect them.

The genetic structure of two epiphytic species, Tillandsia ionantha and T. recurvata, was investigated using enzyme electrophoresis. Electrophoretic data suggest that T. ionantha and T. recurvata differ in breeding system, in agreement with predictions based on their strikingly different floral morphologies. Electrophoretic data suggest extremely high levels of inbreeding for T. recurvata, whereas Tillandsia ionantha exhibits characteristics of an outcrossing species. Values of P, H, and mean number of alleles per locus are much higher in T. ionantha than in T. recurvata. The mean value of FIS for T. ionantha is low (0.056), closely approaching expectations at Hardy‐Weinberg equilibrium. In contrast, the mean value of FIS in T. recurvata (1.000) indicates a complete absence of heterozygotes. The two species also differ in genetic structure. Low FST values for T. ionantha indicate little variation in allele frequencies among populations. In contrast, FST values are high for T. recurvata, suggesting substantial genetic heterogeneity among populations. In addition, the mean value of I is higher in T. ionantha (0.995) than in T. recurvata (0.931). Population genetic data are in agreement with the suggestion of Benzing (1978), who proposed that extreme epiphytes such as T. recurvata, would be characterized by increased autogamy ensuring high seed set. Due to high chromosome numbers in Bromeliaceae (most taxa have x = 25), the family has been considered polyploid. However, with the exception of an additional isozyme for PGM in T. recurvata, the two species are isozymically diploid.

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