Abstract # 118:

Scheduled for Saturday, June 19, 2010 10:45 AM-10:55 AM: Session 19 (Mezzanine Ballroom A/B/C/D) Oral Presentation


VARIATION IN NOCTURNAL LEMUR COLOR VISION: ECOLOGICAL CORRELATES OF DIFFERENTIAL SELECTION

C. C. Veilleux1, D. A. Bolnick1 and E. E. Louis2
1University of Texas at Austin, Department of Anthropology, 1 University Station C3200, Austin, TX 78712, USA, 2Henry Doorly Zoo
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Unlike other nocturnal primates, nocturnal lemurs vary in color vision abilities. Tarsiers are uniformly dichromats, while all Aotus and lorisiforms are monochromats, having lost blue-sensitive S cones due to relaxed selection for dichromatic color vision. Nocturnal lemurs include both dichromats and monochromats, presumably the result of variation in selective pressure for dichromatic color vision. Currently, little research has explored ecological factors driving this differential selection in lemurs. We examined the effects of habitat light environments on selection on the S-opsin gene (coding for S cone production) in three nocturnal lemur genera. We sequenced the gene in Avahi [N=15], Lepilemur [N=22], and Phaner [N=18] from populations sampled across Madagascar. We compared nucleotide diversities of nonsynonymous and silent mutations and conducted tests to identify selection differences between congeners from different habitats (dry/spiny forest vs. rainforest). Our results suggest that light environment, microhabitat, and diet may affect S-opsin gene selection in nocturnal lemurs. Folivorous Lepilemur and Avahi exhibit different selection patterns, suggesting possible microhabitat effects on selection. For Lepilemur, nonsynonymous and silent nucleotide diversity suggests differential selection between Lepilemur populations from different habitats. In contrast, Avahi from both habitats exhibit evidence of purifying selection for dichromatic color vision. All Phaner exhibit a premature stop codon in Exon 1, representing potential S cone loss. We suggest Phaner’s gummivorous diet may have led to relaxed selection for dichromatic color vision.