Explore the vast range of titles available.

Smallholder farmers represent the majority of food producers around the world, yet they are often the most at risk of suffering yield gaps and not achieving their production potential. Ecological Intensification (EI) is a knowledge intensive approach to sustainable agricultural intensification which utilizes biodiversity‐based ecosystem services to support greater yield and reduce reliance on agrochemical inputs. Despite the potential benefit of EI based practices, uptake by smallholders is not as widespread as it could be. Here we test the hypothesis that application of EI on smallholder farms in Kenya is a viable approach that could be taken in order to enhance food security. Focusing on natural pest control and crop pollination, we used farmer surveys to explore the potential for EI in central Kenya. We identified to what extent farm typology and access to knowledge determine the incentives and barriers facing smallholder producers and how this influences optimal pathways for sharing knowledge and providing extension services. We found considerable potential for EI of smallholder farms in this region; most farmers grew insect pollinated crops and some farmers already employed EI practices, while others relied heavily on chemical pesticides. Based on physical, social, and economic factors, three farm typologies emerged including “semi‐commercial,” “market orientated,” and “subsistence.” These typologies influenced the appropriate EI practices available to farmers, as well as routes through which knowledge was shared, and the extent to which extension services were utilized. We propose that to support effective uptake of EI practices, smallholder farm heterogeneity should be acknowledged and characterized in order to target the needs and capabilities of farmers and identify appropriate knowledge sharing and support pathways. The approach we take here has the potential to be employed in other regions globally. Ecological intensification has the potential to improve food security in smallholder farms in Kenya. However, smallholder farms vary considerably based on socioeconomic factors, and farm typologies influenced the appropriate EI practices available to farmers, as well as routes through which extension support can be provided. To support widespread uptake of EI practices, smallholder farm heterogeneity should be acknowledged and characterized in order to target the needs and capabilities of farmers and identify appropriate knowledge sharing and support pathways.

Citizen science is gaining increasing prominence as a tool for science and engagement. However, despite being a potentially valuable tool for sustainable development, citizen science has little visibility in many developing countries. We undertook a collaborative prioritisation process with experts in conservation and the environment to assess the potential of environmental citizen science in East Africa, including its opportunities, benefits and barriers. This provided principles that are applicable across developing countries, particularly for large‐scale citizen science. We found that there was great potential for citizen science to add to our scientific knowledge of natural resources and biodiversity trends. Many of the important benefits of citizen science were for people, as well as the environment directly. Major barriers to citizen science were mostly social and institutional, although projects should also consider access to suitable technology and language barriers. Policy implications. Citizen science can provide data to support decision‐making and reporting against international targets. Participation can also provide societal benefits, informing and empowering people, thus supporting the United Nations’ Sustainable Development Goals. In developing countries, innovation is needed to further develop culturally relevant citizen science that benefits participants and end users. This should be supported through regional networks of stakeholders for sharing best practice. Foreign Language Swahili Sayansi ya wananchi inaendelea kuongezeka kwa umaarufu kama chombo cha sayansi na ushiriki. Hata hivyo, licha ya kuwa chombo cha thamani cha maendeleo endelevu, sayansi ya wananchi haionekani sana katika nchi nyingi zinazoendelea. Tulifanya mchakato wa ushirikiano wa kutoa vipaumbele pamoja na wataalamu wa uhifadhi na mazingira ili kuchunguza uwezekano wa sayansi ya wananchi ya mazingira katika Afrika ya Mashariki, ikijumuisha fursa, faida na vikwazo. Hii ilitoa kanuni zinazoweza kutumika katika nchi zinazoendelea, hasa kwa sayansi ya wananchi kwa kiwango kikubwa. Tuligundua kuwa kuna uwezo mkubwa wa sayansi ya wananchi ili kuongeza ujuzi wetu wa kisayansi kuhusu nyenzo za asili na mielekeo ya bioanuwai. Faida muhimu nyingi za sayansi ya wananchi zilikuwa kwa watu, lakini moja kwa moja kwa mazingira pia. Vikwazo vikuu kwa sayansi ya wananchi vilikuwa kijamii na kitaasisi hasa, ingawa miradi inapaswa pia kufikiria upatikanaji wa teknolojia zinazofaa na vikwazo vya lugha. Athari za sera ni kama ifuatavyo. Sayansi ya wananchi inaweza kutoa data kusaidia kuunda maamuzi na kuandika ripoti ili kufikia malengo ya kimataifa. Ushiriki unaweza pia kutoa faida za jamii, kuwajulisha na kuwawezesha watu na kwa hiyo kuunga mkono Malengo ya Maendeleo ya Umoja wa Mataifa. Katika nchi zinazoendelea kunahitaji kuwa na ubunifu ili kuendeleza sayansi ya wananchi inayofaa utamaduni inayopata washiriki na watumiaji wa mwisho. Hii inapaswa kuungwa mkono kupitia mitandao ya kikanda ya washikadau kwa kugawana taratibu bora.

Deciphering the evolutionary processes driving nucleotide variation in multiallelic genes is limited by the number of genetic systems in which such genes occur. The complementary sex determiner (csd) gene in the honey bee Apis mellifera is an informative example for studying allelic diversity and the underlying evolutionary forces in a well-described model of balancing selection. Acting as the primary signal of sex determination, diploid individuals heterozygous for csd develop into females, whereas csd homozygotes are diploid males that have zero fitness. Examining 77 of the functional heterozygous csd allele pairs, we established a combinatorical criteria that provide insights into the minimum number of amino acid differences among those pairs. Given a data set of 244 csd sequences, we show that the total number of csd alleles found in A. mellifera ranges from 53 (locally) to 87 (worldwide), which is much higher than was previously reported (20). Using a coupon-collector model, we extrapolate the presence of in total 116–145 csd alleles worldwide. The hypervariable region (HVR) is of particular importance in determining csd allele specificity, and we provide for this region evidence of high evolutionary rate for length differences exceeding those of microsatellites. The proportion of amino acids driven by positive selection and the rate of nonsynonymous substitutions in the HVR-flanking regions reach values close to 1 but differ with respect to the HVR length. Using a model of csd coalescence, we identified the high originating rate of csd specificities as a major evolutionary force, leading to an origin of a novel csd allele every 400,000 years. The csd polymorphism frequencies in natural populations indicate an excess of new mutations, whereas signs of ancestral transspecies polymorphism can still be detected. This study provides a comprehensive view of the enormous diversity and the evolutionary forces shaping a multiallelic gene.

Identifying the forces shaping intraspecific phenotypic and genotypic divergence are of key importance in evolutionary biology. Phenotypic divergence may result from local adaptation or, especially in species with strong gene flow, from pronounced phenotypic plasticity. Here, we examine morphological and genetic divergence among populations of the western honey bee Apis mellifera in the topographically heterogeneous East African region. The currently accepted “mountain refugia hypothesis” states that populations living in disjunct montane forests belong to a different lineage than those in savanna habitats surrounding these forests. We obtained microsatellite data, mitochondrial sequences, and morphometric data from worker honey bees collected from feral colonies in three montane forests and corresponding neighboring savanna regions in Kenya. Honey bee colonies from montane forests showed distinct worker morphology compared with colonies in savanna areas. Mitochondrial sequence data did not support the existence of the two currently accepted subspecies. Furthermore, analyses of the microsatellite data with a Bayesian clustering method did not support the existence of two source populations as it would be expected under the mountain refugia scenario. Our findings suggest that phenotypic plasticity rather than distinct ancestry is the leading cause behind the phenotypic divergence observed between montane forest and savanna honey bees. Our study thus corroborates the idea that high gene flow may select for increased plasticity. Morphometric differences exist among workers sampled in distinct Kenyan regions linked to altitude. The degree of genetic differentiation among these populations suggest a phenotypic plastic response to the environment.

The worker caste of polymorphic ant species consists of individuals of strikingly different morphologies. Most studies of polymorphic species have focused on intracolonial allometries and their association with division of labour and task performance of workers of different physical subcastes. However, the factors driving the evolution of these allometries are poorly understood. Here, we analyse the importance of life-style (hypogaeic vs intermediate vs epigaeic) as a factor in the evolution of allometries of functionally important body traits in Dorylus army ants in the context of an evolutionary scenario according to which a hypogaeic life-style is the ancestral state in this group. To this end, we conducted a detailed comparative analysis of the allometries of nine characters for ten species belonging to all six currently recognized subgenera and showing different life-styles. Eight of the nine traits under consideration show a clear increase in relative size from hypogaeic to intermediate to epigaeic life-style. These results strongly suggest that shifts in ecological niche are linked with adaptations in these traits. The degree of overall differentiation among species is more pronounced in larger than in smaller workers. The pattern of division of labour in the epigaeic D. molestus indicates that two factors that may have caused this phenomenon are new food habits and an increased need for colony defence.