Using text-mined trait data to test for cooperate-and-radiate co-evolution between ants and plants

Area of Science:

• Ecology
• Evolutionary Biology
• Biogeography

Background:

• Mutualisms can act as key innovations, potentially accelerating the diversification of interacting lineages.
• Previous research indicates plant diversification increases with ant mutualists, but reciprocal effects in ants remain unclear.

Purpose of the Study:

• To investigate whether ant-plant mutualisms accelerate diversification in ant lineages.
• To determine if ants and plants exhibit a
• cooperate-and-radiate
• dynamic.

Main Methods:

• A novel text-mining approach identified ant species involved in plant defensive or seed dispersal mutualisms.
• Diversification patterns in ants were analyzed using phylogenetic comparative methods, including BiSSE, BAMM, and Hidden State Speciation and Extinction (HiSSE) models.

Main Results:

• Initial analyses using BiSSE and BAMM suggested elevated diversification rates in mutualistic ants.
• The best-fitting model was HiSSE, indicating that unmeasured traits influence diversification.
• The HiSSE model revealed that mutualism decreases diversification, as it evolved in already rapidly diversifying lineages and subsequently slowed their rates.

Conclusions:

• Ant-plant mutualism does not appear to accelerate ant diversification.
• Ant lineages likely radiated first, and then engaged in mutualistic relationships with plants, which subsequently constrained their diversification.