The diploid hybrid species Helianthus deserticola inhabits the desert floor, an extreme environment relative to its parental species Helianthus annuus and Helianthus petiolaris. Adaptation to the desert floor may have occurred via selection acting on transgressive, or extreme, traits in early hybrids between the parental species. We explored this possibility through a field experiment in the hybrid species' native habitat using H. deserticola, H. annuus, H. petiolaris, and two populations of early-generation (BC 2 ) hybrids between the parental species, which served as proxies for the ancestral genotype of the ancient hybrid species. Character expression was evaluated for each genotypic class. Helianthus deserticola was negatively transgressive for stem diameter, leaf area, and flowering date, and the latter two traits are likely to be advantageous in a desert environment. The BC 2 hybrids contained a range of variation that overlapped these transgressive trait means, and an analysis of phenotypic selection revealed that some of the selective pressures on leaf size and flowering date, but not stem diameter, would move the BC 2 population toward

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This paper presents a critical review of current social, economic and policy issues relevant to marine aquaculture (mariculture) in Europe. Tools for identifying the full range of social, economic and environmental issues that influence the sustainable development of mariculture are examined. Under present sectoral approaches to policy, investment, development planning and natural resources management, these issues continue to be treated in isolation. The four main challenges presented in this paper are: (i) how to create a more objective information base with which to assess the social, economic and environmental factors that condition the sustainability of mariculture; (ii) how to provide information from different disciplines in an easy to obtain and compatible format; (iii) how to better integrate knowledge and skills from different disciplines to create a holistic and robust framework for assessing options for mariculture development that integrates social, economic and environmental parameters; and (iv) the effective integration of these assessments into the formulation of policy, investment strategies, spatial plans and natural resources management for coastal areas. Specific issues that need to be addressed within the framework for the integrated evaluation of the economic, social and environmental parameters governing the sustainable development of mariculture include: • development of more accurate information on the economic, social and environmental benefits and costs of well‐planned and managed mariculture; • clearer definition of gaps in existing knowledge on factors critical to the sustainable and equitable development of mariculture; • development of pro‐active consideration of the coastal land and water resource requirements of mariculture as part of strategic economic planning, spatial planning and natural resources management; • the need for more equitable treatment of mariculture regarding rights of access to sites for development and use of resources; • development of awareness among decision‐makers, planners, and managers from different sectoral agencies of the contribution that mariculture may make in promoting the sustainable use of coastal ecosystems; • promotion of a shift in emphasis away from controlling the end use of resources and toward a more balanced approach to coastal development where emphasis is also given to maintaining the health and productivity of coastal ecosystems and the resources they generate that sustain different forms of activity, including mariculture.

Sexually dimorphic traits in many mate recognition systems have evolved in response to preexisting female biases. These biases are often quite general in form and are likely to be shared by predators, thereby imposing a cost on male trait expression. The Mexican tetra Astyanax mexicanus (Pisces: Characidae), a visual predator of swordtail fishes, exhibits the same visual preferences for male body size morphs as do females. Furthermore, tetras in populations where swordtails are absent prefer males with sword ornaments over males with swords removed. The predator preference is thus likely to have arisen prior to contact with fishes bearing the ornament, as has also been suggested for mating preferences for swords.

This study aimed to explore medical students' beliefs about medical education in the light of recent General Medical Council (GMC) recommendations for change and to examine how these beliefs relate to the students' year of training. All undergraduate medical students at a London medical school were given a questionnaire concerning basic sociodemographic information and levels of agreement with a number of statements relating to medical education. The response rate was 75.4% (n = 383). Most students agreed with the majority of recommendations for change. However, two key recommendations, 'more community-based teaching' and 'more optional courses', were supported by only 50.2 and 46.3% of respondents, respectively. Using factor analysis, students' responses were classified into five educational belief orientations relating to 'psychosocial' (e.g. communication skills), 'scientific' (e.g. new technologies), 'active' (e.g. optional courses), 'reform' (e.g. decreasing factual load) and 'group' (e.g. small-group teaching) educational belief orientations. The results showed variations in students' belief orientations across the 5 years of training. The results are discussed in terms of their implications for implementing the GMC recommendations and the impact of medical education on students' belief systems.