Worldwide diversity in mammalian life histories: Environmental realms and evolutionary adaptations

• Published in: Ecology letters Vol. 27; no. 5; pp. e14445 - n/a
• Main Authors: Beccari, E., Capdevila, P., Salguero‐Gómez, R., Carmona, C. P.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.05.2024
• Subjects: Adaptation; Adaptation, Physiological; Animals; Biodiversity; Biological Evolution; brain mass; Ecological adaptation; ecology; Environment; functional diversity; Life history; Life History Traits; Mammals; mode‐of‐life; Seals; Species; Terrestrial environments; life‐history; functional diversity; mode‐of‐life; ecology; brain mass
• ISSN: 1461-023X; 1461-0248
• DOI: 10.1111/ele.14445

Mammalian life history strategies can be characterised by a few axes of variation, conforming a space where species are positioned based on the life history strategies favoured in the environment they exploit. Yet, we still lack global descriptions of the diversity of realised mammalian life history and how this diversity is shaped by the environment. We used six life history traits to build a life history space covering worldwide mammalian adaptation, and we explored how environmental realms (land, air, water) influence mammalian life history strategies. We demonstrate that realms are tightly linked to distinct life history strategies. Aquatic and aerial species predominantly adhere to slower life history strategies, while terrestrial species exhibit faster life histories. Highly encephalised terrestrial species are a notable exception to these patterns. Furthermore, we show that different mode of life may play a significant role in expanding the set of strategies exploitable in the terrestrial realm. Additionally, species transitioning between terrestrial and aquatic realms, such as seals, exhibit intermediate life history strategies. Our results provide compelling evidence of the link between environmental realms and the life history diversity of mammals, highlighting the importance of differences in mode of life to expand life history diversity. Employing six life history traits across 3438 mammalian species, we explored patterns in life history strategies. We demonstrate that worldwide mammals aggregate around two opposite strategies: fast and slow pace of life, with few intermediates. Environmental realms (land, air, water, semi‐aquatic) emerge as robust predictors of this dichotomy. Notably, differences in species' ecological adaptations, like mode of life, substantially expand the diversity of strategies within each realm.