Biology subjects

Godfrey, L. R.

Publications and source records attributed to Godfrey, L. R..

3 recordsLinked to original sources

bioRxiv2026

Ancient mitogenomes reveal unexpected diversity in Madagascar's extinct hippopotamuses

Madagascar's extinct hippopotamuses were a distinctive component of the island's recently lost megafauna, yet their origins, diversification history, and taxonomy have remained unresolved. Here, we recover the first ancient mitochondrial genomes from Malagasy hippopotamuses, obtaining phylogenetic data from 37 subfossil specimens across seven localities and all three named species, and integrate these data with morphology and total-evidence phylogenetic analyses. The 35 endemic specimens form a single clade most closely related to Hippopotamus amphibius, supporting a single colonization of Madagascar. Within this radiation, five deeply divergent and geographically structured mitochondrial lineages diversified across most regions of Madagascar during the Pleistocene. Tip-dating estimates a remarkably young crown age of ~1.41 Ma, following divergence from mainland Hippopotamus at ~3.24 Ma. These lineages do not map cleanly onto traditional taxonomy: material assigned to H. lemerleispans several divergent clades, while H. laloumena and H. madagascariensis are nested within this broader diversity. Morphology supports some lineage assignments but also points to previously unrecognized diversity, while ancestral-state reconstruction supports early body-size reduction followed by a secondary increase in H. laloumena. Malagasy hippopotamuses therefore represent an exceptionally recent radiation of large-bodied island mammals (and the youngest in Madagascar), showing that Madagascar continued to generate endemic mammalian diversity well into the Pleistocene. Their late-Holocene extinction erased the product of more than a million years of rapid insular diversification, the drivers of which remain enigmatic.

evolutionary biology↗

bioRxiv2020

Evolutionary and phylogenetic insights from a nuclear genome sequence of the extinct, giant subfossil koala lemur Megaladapis edwardsi

No endemic Madagascar animal with body mass >10 kg survived a relatively recent wave of extinction on the island. From morphological and isotopic analyses of skeletal subfossil remains we can reconstruct some of the biology and behavioral ecology of giant lemurs (primates; up to ~160 kg), elephant birds (up to ~860 kg), and other extraordinary Malagasy megafauna that survived well into the past millennium. Yet much about the evolutionary biology of these now extinct species remains unknown, along with persistent phylogenetic uncertainty in some cases. Thankfully, despite the challenges of DNA preservation in tropical and sub-tropical environments, technical advances have enabled the recovery of ancient DNA from some Malagasy subfossil specimens. Here we present a nuclear genome sequence (~2X coverage) for one of the largest extinct lemurs, the koala lemur Megaladapis edwardsi (~85kg). To support the testing of key phylogenetic and evolutionary hypotheses we also generated new high-coverage complete nuclear genomes for two extant lemur species, Eulemur rufifrons and Lepilemur mustelinus, and we aligned these sequences with previously published genomes for three other extant lemur species and 47 non-lemur vertebrates. Our phylogenetic results confirm that Megaladapis is most closely related to the extant Lemuridae (typified in our analysis by E. rufifrons) to the exclusion of L. mustelinus, which contradicts morphology-based phylogenies. Our evolutionary analyses identified significant convergent evolution between M. edwardsi and extant folivorous primates (colobine monkeys) and ungulate herbivores (horses) in genes encoding protein products that function in the biodegradation of plant toxins and nutrient absorption. These results suggest that koala lemurs were highly adapted to a leaf-based diet, which may also explain their convergent craniodental morphology with the small-bodied folivore Lepilemur.

genomics↗

bioRxiv2020

Potential evolutionary body size reduction in a Malagasy primate (Propithecus verreauxi) in response to human size-selective hunting pressure

The Holocene arrival of humans on Madagascar precipitated major changes to the islands biodiversity. The now-extinct, endemic "subfossil" megafauna of Madagascar were likely hunted by the islands early human inhabitants. Perhaps in part due to preferential hunting of larger prey, no surviving species on Madagascar is larger than 10 kg. Outside of Madagascar, size-selective hunting pressure has resulted in the phyletic dwarfism of many still-living species across a diversity of phyla. On Madagascar, some subfossil bones of extant lemurs are considerably larger than those of the modern members of their species, but relatively large distances between the subfossil localities and modern samples that have been compared to date makes it impossible to reject the possibility that these size differences more simply reflect pre-existing ecogeographic variation. Here, we used high-resolution 3D scan data to conduct comparative morphological analyses of subfossil and modern skeletal remains of one of the larger extant lemurs, Verreauxs sifakas (Propithecus verreauxi) from subfossil and modern sites [~]10 km adjacent: Taolambiby (bones dated to 725-560 - 1075-955 cal. years before present) and Beza Mahafaly Special Reserve, respectively. We found that the average subfossil sifaka bone (n=12) is 9% and significantly larger than that of modern sifakas (n=31 individuals; permutation test; p=0.037). When restricting the analysis to the single element and side with the largest representation in the subfossil sample (n=4 right distal femora), the average subfossil bone is 10% larger (p=0.046). While we cannot yet conclude whether this size difference reflects evolutionary change or an archaeological aggregation/taphonomic process, if this is a case of phyletic dwarfism in response to human size-selective harvesting pressures then the estimated rate of evolutionary change is slightly higher than that previously calculated for other archaeological cases of this phenomenon.

evolutionary biology↗