Recurrent Evolution of Melanism in South American Felids

Abstract

Morphological variation in natural populations is a genomic test bed for studying the interface between molecular evolution and population genetics, but some of the most interesting questions involve non-model organisms that lack well annotated reference genomes. Many felid species exhibit polymorphism for melanism but the relative roles played by genetic drift, natural selection, and interspecies hybridization remain uncertain. We identify mutations of Agouti signaling protein (ASIP) or the Melanocortin 1 receptor (MC1R) as independent causes of melanism in three closely related South American species: the pampas cat (Leopardus colocolo), the kodkod (Leopardus guigna), and Geoffroy’s cat (Leopardus geoffroyi). To assess population level variation in the regions surrounding the causative mutations we apply genomic resources from the domestic cat to carry out clone-based capture and targeted resequencing of 299 kb and 251 kb segments that contain ASIP and MC1R, respectively, from 54 individuals (13–21 per species), achieving enrichment of ~500–2500-fold and ~150x coverage. Our analysis points to unique evolutionary histories for each of the three species, with a strong selective sweep in the pampas cat, a distinctive but short melanism-specific haplotype in the Geoffroy’s cat, and reduced nucleotide diversity for both ancestral and melanism-bearing chromosomes in the kodkod. These results reveal an important role for natural selection in a trait of longstanding interest to ecologists, geneticists, and the lay community, and provide a platform for comparative studies of morphological variation in other natural populations.

Mapping black panthers: Macroecological modeling of melanism in leopards (Panthera pardus)

“…The occurrence of melanism is common in the cat family (Felidae), having been documented in 13 of its 37 species, and having arisen independently at least eight times in the family [12–14]. Interestingly, this variant phenotype seems to always be maintained as a polymorphism, never reaching species-wide fixation in any felid.…”

Ecology and Evolution of Melanism in Big Cats: Case Study with Black Leopards and Jaguars

“…The occurrence of melanism is rather common in Felidae, having been documented in 13 of the 38 felid species, evolved independently at least eight times within the family [11][12][13], in some cases reaching very high frequencies in natural populations [14,15]. In none of them has it reached fixation, but rather always exists as a polymorphic phenotype, and it is present only in two species of Panthera: the leopard (P. pardus) and the jaguar (P. onca) in contrast of the spotted wild phenotype present in these species.…”

Does polymorphism make the Asiatic golden cat the most adaptable predator in the Eastern Himalayas?

“…We know that color variants arise because of genetic drift or random mutation, but persist and become common in a population through natural selection if they provide ecological advantages (Schneider et al. ). But what could be the possible benefits of occurring in so many different forms in one area?…”