Range size heritability in Carnivora is driven by geographic constraints

Area of Science:

• Evolutionary Biology
• Biogeography
• Phylogenetics

Background:

• Range size heritability describes the tendency for related species to exhibit similar geographic range extents.
• This pattern suggests potential species-level selection but may also be influenced by underlying ecological and geographic factors.

Purpose of the Study:

• To investigate whether range size heritability in Carnivora is an artifact of shared geographic domains (e.g., continents, biomes).
• To explore the mechanisms driving range size heritability, focusing on the interplay of evolutionary and geographic constraints.

Main Methods:

• Utilized a well-resolved phylogeny of Carnivora to analyze range sizes and their relationship with geographic domains.
• Assessed the phylogenetic signal in range sizes before and after accounting for the size of species' geographic domains.
• Examined the impact of different definitions of geographic domains on the observed heritability signal.

Main Results:

• Species' range sizes in Carnivora are significantly constrained by the size of their respective geographic domains.
• The phylogenetic signal in range sizes decreases substantially when geographic domain sizes are statistically controlled.
• A more refined definition of geographic domains further weakens the signal for range size heritability.

Conclusions:

• Range size heritability is not necessarily indicative of species-level selection but can emerge from shared geographic constraints.
• Evolutionary conservatism in niche breadth plays a key role in defining species' geographic domains, which subsequently shape range sizes.
• The observed pattern is a consequence of the interaction between evolutionary conservatism and geographic limitations.