Climatic dissimilarity associated with phylogenetic breaks

Abstract

Shared phylogenetic breaks often are associated with clear geographic barriers but some common phylogeographic breaks may lack obvious underlying mechanisms. A phylogenetic break involving multiple taxa was found in the Baja California Peninsula that was associated with a past sea barrier. However, geological evidence is lacking for this barrier’s past existence, and despite its current absence, the genetic breaks have persisted. This work explores the relationships between the current climatic niches for matrilineages of 11 vertebrate species as a possible explanation for the current geographic partitioning of matrilineages. We evaluated the climatic occupancy of each matrilineage through ecological niche models, background similarity, niche overlap, niche divergence, and Mantel tests. We found disparities in the climatic occupancy between north and south matrilineage of each taxon. Northern matrilineages are associated with lower temperatures and winter rains, while southern matrilineages reside in areas with higher temperatures and summer rains.

Implications of barrier ephemerality in geogenomic research

“…It may be that peninsulas and linear coastlines are particularly conducive for this phenomenon. Second, divergence is amplified under differential selection for low‐dispersing species; along the arid Baja peninsula, there is a strong gradient in the annual amount and seasonality of precipitation (Avila‐Lovera & Garcillán, 2021; Cab‐Sulub & Álvarez‐Castañeda, 2021), both controlled by the North American monsoon (Adams & Comrie, 1997; Higgins et al, 1999), which suggests differential adaptation may also be an important factor for interpreting this signal (Klimova et al, 2018). Importantly, species do not have the same physiology and niche constraints and therefore are not expected to be equally impacted by this gradient.…”

Stepped Geomorphology Shaped the Phylogeographic Structure of a Widespread Tree Species (Toxicodendron vernicifluum, Anacardiaceae) in East Asia

“…These breaks may arise when allopatric populations have experienced long-term isolation across major physiographic barriers to dispersals, such as mountains, rivers, glaciers, and oceans ( Soltis et al, 2006 ; Jaramillo-Correa et al, 2009 ). However, sometimes obvious physical barriers are absent and climate or habitat barriers play a more important role ( Geffen et al, 2004 ; Bai et al, 2016 ; Cab-Sulub and Álvarez-Castañeda, 2021 ). In a given area, co-distributed species may exhibit common phylogeographic breaks because they have a shared biogeographic history ( Arbogast and Kenagy, 2001 ; Soltis et al, 2006 ), but diverse patterns are more frequently observed reflecting the complex history affected by not only a few barriers ( Soltis et al, 2006 ; Shafer et al, 2010 ; Fan et al, 2016 ).…”