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Parental roles in two nuclear gibbon families (Hylobates moloch and Nomascus leucogenys): What do fathers do?
Abstracts / HOMO - Journal of Comparative Human Biology 61 (2010) 204–222
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Genetics, demography and social structure in human variation and health A.H. Bittles, (Murdoch University and Edith Cowan University, Perth, Australia), [email protected] The first decade of the 21st century has seen unprecedented progress on research into human variation, health and disease. While the primary emphasis on genetics is understandable following the success of the Human Genome Project, equivalent examination of other major disciplines that influence the inter-generational transmission of genes has largely been missing. Two diverse but complementary examples illustrate how genetics and the demography and social structure of human populations interact. The first, skin pigmentation, has long been a subject of interest to human biologists. To date, genomic analysis has identified 24 genes coding for skin colour, most of which are ethnic-specific, with evidence of convergent evolution in Asian and European populations. At the same time, the global expansion of human populations has been accompanied by skin colour preferences and prejudices, and both diet and lifestyle impact on pigmentation-associated pathologies, such as rickets and skin cancers. The second example, the single gene disorder -thalassaemia causes a severe inherited anaemia, although carriers of the condition have selective protection against malaria. Some 240 different -thalassaemia mutations have been identified, with a carrier rate in affected populations of 2–19%. Our studies in South Asia have highlighted the major influence of ethnic, religious and social differences on the profile of disease alleles at the community level, which has important consequences in terms of disease diagnosis and prevention. Both examples thus confirm the ongoing roles of population size and stratification in present-day human variation and genetic diseases, and have significant additional evolutionary implications. doi:10.1016/j.jchb.2010.01.006 Parental roles in two nuclear gibbon families (Hylobates moloch and Nomascus leucogenys): What do fathers do? B. Burns, H. Dooley, D. Judge, (The University of Western Australia, Perth, Australia), [email protected] Allocare allows a reduction of the disproportionately female biased parental investment in mammals. In socially monogamous and territorial species, fitness benefits for paternal care of offspring are higher through increased certainty of paternity. Despite this, there is a high degree of variability in paternal investment within and between species, often corresponding with variability in maternal restrictiveness or care. Two captive family groups of gibbons (Hylobates moloch and Nomascus leucogenys) were observed at the Perth Zoo in 2005 and again in 2008 to investigate intra-group differences in time budgets. Both family groups consisted of an adult pair and two offspring (infant, juvenile, adolescent or sub-adult) similar in age between groups. While overall activity levels are lower in the silvery gibbons than in the white-cheeked gibbons, fathers in both groups expended more time (and therefore more energy) than mothers in social play with juvenile offspring (2.5–3.5 years of age). Play between the father and juvenile male in the silvery gibbon group constituted the remaining 10.6% of all social play after sibling play (89.4% of scans involving social play), while the white-cheeked gibbon father played with his juvenile daughter 2.4 times as often as the mother did (2 =5.76, d.f.=1, p<0.025). Despite 2.7% of social play in this group occurring solely between the mother and father, neither adult was observed to join in play with offspring if their mate was already doing so. In both groups and across study years, allogrooming of offspring peaked when offspring were 2.5–5 years of age. Across both years, the mother in the silvery gibbon group spent 6 times more energy on grooming offspring than did the father. Maternal grooming contributed the majority of total grooming effort for the group (69% of scans involving allogrooming). Alternatively, the father in the white-cheeked gibbon group spent more time grooming offspring than did the mother (U=21 308, Z=−2.539, p=0.011). Maternal care of juveniles and subsequently paternal allogrooming of offspring varied between groups, however, investment by both fathers in play with juveniles exceeded that of mothers. doi:10.1016/j.jchb.2010.01.007
205
Genetics, demography and social structure in human variation and health A.H. Bittles, (Murdoch University and Edith Cowan University, Perth, Australia), [email protected] The first decade of the 21st century has seen unprecedented progress on research into human variation, health and disease. While the primary emphasis on genetics is understandable following the success of the Human Genome Project, equivalent examination of other major disciplines that influence the inter-generational transmission of genes has largely been missing. Two diverse but complementary examples illustrate how genetics and the demography and social structure of human populations interact. The first, skin pigmentation, has long been a subject of interest to human biologists. To date, genomic analysis has identified 24 genes coding for skin colour, most of which are ethnic-specific, with evidence of convergent evolution in Asian and European populations. At the same time, the global expansion of human populations has been accompanied by skin colour preferences and prejudices, and both diet and lifestyle impact on pigmentation-associated pathologies, such as rickets and skin cancers. The second example, the single gene disorder -thalassaemia causes a severe inherited anaemia, although carriers of the condition have selective protection against malaria. Some 240 different -thalassaemia mutations have been identified, with a carrier rate in affected populations of 2–19%. Our studies in South Asia have highlighted the major influence of ethnic, religious and social differences on the profile of disease alleles at the community level, which has important consequences in terms of disease diagnosis and prevention. Both examples thus confirm the ongoing roles of population size and stratification in present-day human variation and genetic diseases, and have significant additional evolutionary implications. doi:10.1016/j.jchb.2010.01.006 Parental roles in two nuclear gibbon families (Hylobates moloch and Nomascus leucogenys): What do fathers do? B. Burns, H. Dooley, D. Judge, (The University of Western Australia, Perth, Australia), [email protected] Allocare allows a reduction of the disproportionately female biased parental investment in mammals. In socially monogamous and territorial species, fitness benefits for paternal care of offspring are higher through increased certainty of paternity. Despite this, there is a high degree of variability in paternal investment within and between species, often corresponding with variability in maternal restrictiveness or care. Two captive family groups of gibbons (Hylobates moloch and Nomascus leucogenys) were observed at the Perth Zoo in 2005 and again in 2008 to investigate intra-group differences in time budgets. Both family groups consisted of an adult pair and two offspring (infant, juvenile, adolescent or sub-adult) similar in age between groups. While overall activity levels are lower in the silvery gibbons than in the white-cheeked gibbons, fathers in both groups expended more time (and therefore more energy) than mothers in social play with juvenile offspring (2.5–3.5 years of age). Play between the father and juvenile male in the silvery gibbon group constituted the remaining 10.6% of all social play after sibling play (89.4% of scans involving social play), while the white-cheeked gibbon father played with his juvenile daughter 2.4 times as often as the mother did (2 =5.76, d.f.=1, p<0.025). Despite 2.7% of social play in this group occurring solely between the mother and father, neither adult was observed to join in play with offspring if their mate was already doing so. In both groups and across study years, allogrooming of offspring peaked when offspring were 2.5–5 years of age. Across both years, the mother in the silvery gibbon group spent 6 times more energy on grooming offspring than did the father. Maternal grooming contributed the majority of total grooming effort for the group (69% of scans involving allogrooming). Alternatively, the father in the white-cheeked gibbon group spent more time grooming offspring than did the mother (U=21 308, Z=−2.539, p=0.011). Maternal care of juveniles and subsequently paternal allogrooming of offspring varied between groups, however, investment by both fathers in play with juveniles exceeded that of mothers. doi:10.1016/j.jchb.2010.01.007