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Creators/Authors contains: "Louis, Jr, Edward E."

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  1. Abstract Objectives

    Hair (i.e., pelage/fur) is a salient feature of primate (including human) diversity and evolution—serving functions tied to thermoregulation, protection, camouflage, and signaling—but wild primate pelage evolution remains relatively understudied. Specifically, assessing multiple hypotheses across distinct phylogenetic scales is essential but is rarely conducted. We examine whole body hair color and density variation across Indriidae (Avahi,Indri,Propithecus)—a lineage that, like humans, exhibits vertical posture (i.e., their whole bodies are vertical to the sun).

    Materials and methods

    Our analyses consider multiple phylogenetic scales (family‐level, genus‐level) and hypotheses (e.g., Gloger's rule, the body cooling hypotheses). We obtain hair color and density from museum and/or wild animals, opsin genotypes from wild animals, and climate data from WorldClim. To analyze our data, we use phylogenetic generalized linear mixed models (PGLMM) using Markov chain Monte Carlo algorithms.


    Our results show that across the Indriidae family, darker hair is typical in wetter regions. However, withinPropithecus, dark black hair is common in colder forest regions. Results also show pelage redness increases in populations exhibiting enhanced color vision. Lastly, we find follicle density on the crown and limbs increases in dry and open environments.


    This study highlights how different selective pressures across distinct phylogenetic scales have likely acted on primate hair evolution. Specifically, our data acrossPropithecusmay implicate thermoregulation and is the first empirical evidence of Bogert's rule in mammals. Our study also provides rare empirical evidence supporting an early hypothesis on hominin hair evolution.

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  2. Abstract

    Lemurs are among the world's most threatened mammals. The critically endangered black‐and‐white ruffed lemur (Varecia variegata), in particular, has recently experienced rapid population declines due to habitat loss, ecological sensitivities to habitat degradation, and extensive human hunting pressure. Despite this, a recent study indicates that ruffed lemurs retain among the highest levels of genetic diversity for primates. Identifying how this diversity is apportioned and whether gene flow is maintained among remnant populations will help to diagnose and target conservation priorities. We sampled 209 individuals from 19 sites throughout the remainingV. variegatarange. We used 10 polymorphic microsatellite loci and ~550 bp of mtDNAsequence data to evaluate genetic structure and population dynamics, including dispersal patterns and recent population declines. Bayesian cluster analyses identified two distinct genetic clusters, which optimally partitioned data into populations occurring on either side of theMangoro River. Localities north of the Mangoro were characterized by greater genetic diversity, greater gene flow (lower genetic differentiation) and higher mtDNAhaplotype and nucleotide diversity than those in the south. Despite this, genetic differentiation across all sites was high, as indicated by high averageFST(0.247) and ΦST(0.544), and followed a pattern of isolation‐by‐distance. We use these results to suggest future conservation strategies that include an effort to maintain genetic diversity in the north and restore connectivity in the south. We also note the discordance between patterns of genetic differentiation and current subspecies taxonomy, and encourage a re‐evaluation of conservation management units moving forward.

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