Taxon Cycles in Neotropical Mangroves

Area of Science:

• Paleobotany
• Biogeography
• Evolutionary Ecology

Background:

• The taxon cycle theory describes species' range expansions and contractions, crucial for long-term survival.
• Documented primarily in island faunas, empirical evidence from continental plants is scarce.
• Phylogeographic studies dominate taxon cycle research, lacking direct fossil evidence.

Purpose of the Study:

• To provide empirical fossil evidence for taxon cycles in a Neotropical plant.
• To investigate recurrent expansion/contraction cycles in the mangrove taxon Pelliciera.
• To analyze drivers and implications of these cycles within the taxon cycle theory framework.

Main Methods:

• Analysis of Neotropical pollen records spanning the Eocene to the present.
• Reconstruction of the fossil distribution of Pelliciera.
• Biogeographical, chronological, and ecological assessment of expansion/contraction patterns.

Main Results:

• Empirical fossil evidence demonstrates recurrent Eocene-to-present expansion and contraction cycles in Pelliciera.
• These cycles align with biogeographical, chronological, and ecological predictions of the taxon cycle concept.
• Potential biotic and abiotic drivers for Pelliciera's cycles were identified and analyzed.

Conclusions:

• Pelliciera's cycles represent the first unequivocal empirical documentation of taxon cycles in plants.
• The findings support the applicability of the taxon cycle theory to continental plant species.
• The study discusses the potential trend towards extinction under taxon cycle theory predictions for Pelliciera.