Evolution and phylogeny of old world deer

Area of Science:

• Evolutionary biology
• Molecular phylogenetics
• Mammalogy

Background:

• The evolutionary relationships and timing of diversification within Old World deer (Cervinae) remain incompletely understood.
• Previous classifications have been challenged by limited molecular data.

Purpose of the Study:

• To reconstruct the phylogenetic pattern and timing of the radiation of Old World deer.
• To investigate the evolutionary history of the Cervinae subfamily using molecular data.
• To assess the homoplastic evolution of various character states within Cervinae.

Main Methods:

• Phylogenetic analysis of the complete mitochondrial cytochrome b gene from 33 Cervinae taxa.
• Application of distinct theoretical approaches for rooted and unrooted phylogenies.
• Utilizing reliable fossil calibrations and improved dating methods for molecular timescale construction.

Main Results:

• Strong support for the monophyly of Old World deer, with muntjacs as the sister group.
• Divergence of at least three distinct genera: Rucervus, Dama, and Cervus, with the latter encompassing several previously recognized genera/subgenera.
• Confirmation of paraphyly in nominate C. elaphus and rejection of Axis monophyly.
• Evolutionary radiation of Old World deer occurred at the Miocene/Pliocene transition.
• Estimated average per-lineage diversification rate of 0.51+/-0.1 species per million years over the last 6 million years.

Conclusions:

• The study provides a robust molecular phylogeny for Old World deer, clarifying taxonomic relationships.
• The timing of deer radiation aligns with palaeontological evidence, suggesting a significant diversification event.
• Molecular phylogenies are crucial for understanding the evolution of morphological and behavioral traits in Cervinae.