Platyrrhine (New World) monkeys possess highly polymorphic color vision owing to allelic variation of the single-locus L/M opsin gene on the X chromosome. Most species consist of female trichromats and female and male dichromats. Howlers (genus Alouatta) are an exception; they are considered to be routinely trichromatic with L and M opsin genes juxtaposed on the X chromosome, as seen in catarrhine primates (Old World monkeys, apes, and humans). Yet it is not known whether trichromacy is invariable in howlers. We examined L/M opsin variation in wild howler populations in Costa Rica and Nicaragua (Alouatta palliata) and Belize (A. pigra), using fecal DNA. We surveyed exon 5 sequences (containing the diagnostic 277th and 285th residues for λmax) for 8 and 18 X chromosomes from Alouatta palliata and A. pigra, respectively. The wavelengths of maximal absorption (λmax) of the reconstituted L and M opsin photopigments were 564 nm and 532 nm, respectively, in both species. We found one M–L hybrid sequence with a recombinant 277/285 haplotype in Alouatta palliata and two L–M hybrid sequences in A. pigra. The λmax values of the reconstituted hybrid photopigments were in the range of 546~554 nm, which should result in trichromat phenotypes comparable to those found in other New World monkey species. Our finding of color vision variation due to high frequencies of L/M hybrid opsin genes in howlers challenges the current view that howlers are routine and uniform trichromats. These results deepen our understanding of the evolutionary significance of color vision polymorphisms and routine trichromacy and emphasize the need for further assessment of opsin gene variation as well as behavioral differences among subtypes of trichromacy.Electronic supplementary materialThe online version of this article (doi:10.1007/s10764-013-9705-9) contains supplementary material, which is available to authorized users.

Primates possess remarkably variable color vision, and the ecological and social factors shaping this variation remain heavily debated. Here, we test whether central tenants of the folivory hypothesis of routine trichromacy hold for the foraging ecology of howler monkeys. Howler monkeys (genus Alouatta) and paleotropical primates (Parvorder: Catarrhini) have independently acquired routine trichromacy through fixation of distinct mid‐ to long‐wavelength‐sensitive (M/LWS) opsin genes on the X‐chromosome. The presence of routine trichromacy in howlers, while other diurnal neotropical monkeys (Platyrrhini) possess polymorphic trichromacy, is poorly understood. A selective force proposed to explain the evolution of routine trichromacy in catarrhines—reliance on young, red leaves—has received scant attention in howlers, a gap we fill in this study. We recorded diet, sequenced M/LWS opsin genes in four social groups of Alouatta palliata, and conducted colorimetric analysis of leaves consumed in Sector Santa Rosa, Costa Rica. For a majority of food species, including Ficus trees, an important resource year‐round, young leaves were more chromatically conspicuous from mature leaves to trichromatic than to hypothetical dichromatic phenotypes. We found that 18% of opsin genes were MWS/LWS hybrids; when combined with previous research, the incidence of hybrid M/LWS opsins in this species is 13%. In visual models of food discrimination ability, the hybrid trichromatic phenotype performed slightly poorer than normal trichromacy, but substantially better than dichromacy. Our results provide support for the folivory hypothesis of routine trichromacy. Similar ecological pressures, that is, the search for young, reddish leaves, may have driven the independent evolution of routine trichromacy in primates on separate continents. We discuss our results in the context of balancing selection acting on New World monkey opsin genes and hypothesize that howlers experience stronger selection against dichromatic phenotypes than other sympatric species, which rely more heavily on cryptic foods.

This study is a quantitative examination of primate feeding selectivity in relation to secondary chemistry within a single plant species, Hymenaea courbaril. It provides the first evidence that sesquiterpenes may act as feeding deterrents in mantled howler monkeys. A free-ranging group of mantled howler monkeys at the study site of Sector Santa Rosa, Area de Conservacion Guanacaste, Costa Rica were observed for the 2-month period of H. courbaril leaf flush in 1999. Tree characteristic data and leaf specimens were collected from 22 focal trees. Gas chromatography and mass spectrometry were used to estimate relative percentages of sesquiterpenes in leaf specimens. The monkeys fed only on the youngest leaves and only from particular trees. Whereas leaf stage selectivity was likely governed by tannin content and structural carbohydrates in younger and older leaf stages, respectively, differential tree use may be related to variability in sesquiterpene content. There is evidence that alpha-copaene may have played a role in interindividual tree use, and that cyperene may also be implicated. However, there is no reported evidence of antiherbivore activity for cyperene.

We strive to provide our students with applied and transformational experiences to strengthen and crystallize the coursework within our disciplines and prepare students to conduct research in their later undergraduate years, graduate school, and careers. One of our greatest challenges as educators is training students to conduct research within the constraints of college and department-level requirements and subject to faculty teaching loads and the need for faculty buy-in. I have designed a system for embedding high-impact educational practices and transformational experiences in a stepwise process throughout an undergraduate anthropology curriculum. I support using community-based projects as the vehicle for training students to design and carry out collaborative research, after which they can mentor other students to further refine their training and/or take an upperlevel course that results in a proposal for a capstone research project. Materials for four courses are included, along with assessment tools for measuring student mastery/growth/development. The courses involved are a research design seminar, a methods seminar, a research proposal course, and a seminar on mentoring research design or methods. Suggestions for adjusting faculty workloads are offered. My hope is to (1) provide educators with a ready-made program; (2) demonstrate its feasibility to faculty and its value to students, faculty, and community; and (3) encourage departments to use the tools presented or design their own using these as a template.The value of undergraduate training in, and the conduct of, research has been reported by many educators, for many disciplines (Madan and Teitge 2013 for a review of particular disciplines; see also Russell et al. 2007; Kuh 2008;Lopatto 2010a;Craney et al. 2011). Benefits fall within the areas of personal and scholarly growth and career guidance. In terms of personal development, students report or demonstrate increased self-confidence, independence, creativity, discipline, cognitive development (e.g., analytical and synthetic skills), and feelings of accomplishment (Russell et al. 2007; Lopatto 2008Lopatto , 2010bWayment and Dickson 2008).Besides the obvious development of research skills (formulating research questions, conducting a literature review, designing a project and research methods, collecting and analyzing data, and reporting of results), students benefit scholastically in other direct and indirect ways. Applied and research experience help to crystallize what students learn in the foundational courses within their major, via "reallife" experience (https://www.utexas.edu/ugs/our/conduct/ models). As Madan and Teitge (2013, 1) state, "…only after forming one's own hypotheses does one truly understand the nuances of research designs and better conceptualize course material." Students begin to think like scientists, and the more they participate in research design, the better they become at tailoring methods to answer proposed questions (Russell et al. 2007; Lopatto 2008;Madan a...

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