Out of the dark: 350 million years of conservatism and evolution in diel activity patterns in vertebrates

Abstract

Many animals are active only during a particular time (e.g., day vs. night), a partitioning that may have important consequences for species coexistence. An open question is the extent to which this diel activity niche is evolutionarily conserved or labile. Here, we analyze diel activity data across a phylogeny of 1914 tetrapod species. We find strong phylogenetic signal, showing that closely related species tend to share similar activity patterns. Ancestral reconstructions show that nocturnality was the most likely ancestral diel activity pattern for tetrapods and many major clades within it (e.g., amphibians, mammals). Remarkably, nocturnal activity appears to have been maintained continuously in some lineages for ∼350 million years. Thus, we show that traits involved in local-scale resource partitioning can be conserved over strikingly deep evolutionary time scales. We also demonstrate a potentially important (but often overlooked) metric of niche conservatism. Finally, we show that diurnal lineages appear to have faster speciation and diversification rates than nocturnal lineages, which may explain why there are presently more diurnal tetrapod species even though diurnality appears to have evolved more recently. Overall, our results may have implications for studies of community ecology, species richness, and the evolution of diet and communication systems.

The global biogeography of lizard functional groups

“…As opposed to the other strategies, the nocturnal strategy is dominated by a specific clade – the Gekkota (Appendix S9), although it contains members of other clades as well (notably Australian Lerista skinks). This finding is compatible with previous studies that found that diel activity is highly phylogenetically conserved (Anderson & Wiens, ; Roll, Dayan, & Kronfeld‐Schor, ; Vidan et al, ). This raises two interesting questions for future research: (a) Why does nocturnality seldom occur in the New World; and (b) Why does nocturnality remain almost exclusively (94% of species) a gekkotan trait?…”

Effects of parental care on resource allocation into immune defense and buccal microbiota in mouthbrooding cichlid fishes*

“…Differences in sample numbers between the analyses can be explained by either too low RNA yield for gene expression analysis or failed runs on the flow cytometer during fieldwork. Pagel's λ was calculated for all variables to determine the strength of the phylogenetic signal for each parameter (Pagel 1999;Münkemüller et al 2012;Cooper et al 2016;Anderson and Wiens 2017) (R package PHYTOOLS, command phylosig (Revell 2012)).…”

Ecology and macroevolution – evolutionary niche monopolisation as a mechanisms of niche conservatism

“…At larger scales it may compete with genetic constraints or biogeographic contingencies. As an example, Peixoto et al () find climatic (β‐) niche conservatism among bats at the level of order or family, but not at lower levels. The same pattern was found in the geophylogenetic patterns of Floridian plant communities (Cavender‐Bares et al 2006).…”

“…However, other authors have found the opposite pattern, i.e. α ‐niche conservatism (Richman and Price , Ackerly et al 2006, Sallan and Friedman , Muschick et al 2014, Anderson and Wiens ), and sometimes there is no clear signal (Ingram and Shurin , Bernard‐Verdier et al 2013).…”