Longevity in plants impacts phylogenetic and population dynamics

Area of Science:

• Evolutionary Biology
• Plant Science
• Phylogenetics

Background:

• Phylogenies of long-lived plants often display short molecular branch lengths and high gene-tree conflict.
• The underlying biological mechanisms driving these phylogenetic patterns are not well understood.

Purpose of the Study:

• To investigate the biological mechanisms, specifically life history traits, that contribute to short molecular branches and gene-tree conflict in long-lived plants.
• To compare simulation outcomes with empirical phylogenomic data from seed plant clades.

Main Methods:

• Utilized an agent-based simulation model to explore the effects of varying lifespan, overlapping generations, and somatic mutation.
• Empirically examined phylogenomic patterns in seed plant datasets, considering life-history shifts.

Main Results:

• Lifespan and overlapping generations were found to generate both short branches and elevated gene-tree conflict.
• Somatic mutation can amplify these effects, but typically at rates too low for major phylogenetic impact.
• Simulation results mirrored observed phylogenomic diversity across plant lineages with different life histories.

Conclusions:

• Lifespan and generation overlap are significant contributors to the characteristic phylogenetic signatures observed in long-lived plants.
• Life history traits must be considered when interpreting evolutionary patterns, substitution rates, and lineage heterogeneity in these plants.