Iterative evolution of large-bodied hypercarnivory in canids benefits species but not clades

Abstract

Ecological specialization has costs and benefits at various scales: traits benefitting an individual may disadvantage its population, species or clade. In particular, large body size and hypercarnivory (diet over 70% meat) have evolved repeatedly in mammals; yet large hypercarnivores are thought to be trapped in a macroevolutionary "ratchet", marching unilaterally toward decline. Here, we weigh the impact of this specialization on extinction risk using the rich fossil record of North American canids (dogs). In two of three canid subfamilies over the past 40 million years, diversification of large-bodied hypercarnivores appears constrained at the clade level, biasing specialized lineages to extinction. However, despite shorter species durations, extinction rates of large hypercarnivores have been mostly similar to those of all other canids. Extinction was size-and carnivory-selective only at the end of the Pleistocene epoch 11,000 years ago, suggesting that large hypercarnivores were not disadvantaged at the species level before anthropogenic influence.

The first hunting dog from Dmanisi: comments of social behaviour in Canidae and hominins

“…3). According to the loadings of the variables in the discriminant function, the hypercarnivores show third premolars that are relatively mesiodistally shorter and buccolingually narrower compared to those of omnivorous species, as well as a carnassial with an enlarged trigonid blade and a reduced talonid basin, and a deeper, more stoutly-built corpus, which is in agreement with previous analyses of adaptations in canids towards hypercarnivory 28,29 . This function reclassi ed unequivocally the individual from Dmanisi (values of the variables obtained from D6327) in the group of hypercarnivores (Fig.…”

SARS-CoV-2: Cross-scale Insights from Ecology and Evolution

“…• Macroevolution has revealed surprising ways that species persistence and diversification can be decoupled from forces governing individual fitness [e.g., selection has repeatedly favored traits associated with mammalian hypercarnivory (e.g., bone-cracking) at the individual level, but these lineages are more vulnerable to extinction than generalist clades [95]] [96,97], and may offer new perspectives on cross-scale phenomena in viruses such as the evolution of virulence. • The concept of ecological adaptive radiation links ecological opportunity (e.g., absence of competitors when novel habitats are colonized) to the rapid proliferation of new species adapted to distinct niches.…”

Indo além de modelos dependentes de diversidade: uma visão mais mecanística do efeito da competição interespecífica na radiação de Canidae

“…Such increase in body size seems to be correlated with increasing adaptations to hypercarnivory, an ecological specialization towards large prey consumption (Van Valkenburgh et al, 2004). Specialization to extreme morphologies (either small hypocarnivores or larger hypercarnivores) seems to lead to short living species (Balisi et al, 2018), but hypercarnivory per se seems to imply an extinction selective regime only at certain time periods and do not seem correlated to extinction dynamics as a whole (Balisi & Van Valkenburgh, 2020). Slater (2015) has argued that the evolution of canid morphological traits followed patterns of repeated ecological radiations in a bounded morphospace of restricted diet categories.…”

“…Canidae is a family of predatory mammals comprising both extant and extinct lineages, with its origins in the Paleogene of North America, having existed for some 40 million years until the present day (Wang & Tedford, 2008). The Canidae fossil record of North America is considerably well documented in both its taxonomic diversity and sampling (Tedford et al, 2009;Wang, 1994;Wang et al, 1999), and eco-morphological characterization (Balisi et al, 2018;Balisi & Van Valkenburgh, 2020;Janis et al, 1998;Slater, 2015;Van Valkenburgh et al, 2004). Extinct canid species display a wide array in both body size and diet, ranging from small predators of small prey and plant matter (hypocarnivory), to large-bodied bone-crushing or hypercarnivore (whose diet is almost entirely composed of meat) dogs (Van Valkenburgh, 1991;Wang & Tedford, 2008).…”

“…Many studies concerning macroevolutionary competitive dynamics of canids (as well as on other lineages) have focused either on diversity-dependence diversification dynamics (Silvestro et al, 2015), or morphological evolution of species traits (Slater, 2015), or on the implications of such morphological evolution on species survival and extinction risk (Balisi et al, 2018;Balisi & Van Valkenburgh, 2020;Van Valkenburgh et al, 2004). The effect of competition on diversification dynamics has been tested fairly indirectly and relied on the assumption that an increase in diversity implies in stronger competition, which would lead to a drop in speciation or rise in extinction rates.…”