Evolutionary history as a driver of ecological networks: a case study of plant-hummingbird interactions

The distinctive ant genus Leptomyrmex Mayr, 1862 had been thought to be endemic to Australasia for over 150 years, but enigmatic Neotropical fossils have challenged this view for decades. The present study responds to a recent and surprising discovery of extant Leptomyrmex species in Brazil with a thorough evaluation of the Dominican Republic fossil material, which dates to the Miocene. In the first case study of direct fossil inclusion within Formicidae Latreille, 1809, we incorporated both living and the extinct Leptomyrmex species. Through simultaneous analysis of molecular and morphological characters in both Bayesian and parsimony frameworks, we recovered the fossil taxon as sister-group to extant Leptomyrmex in Brazil while considering the influence of taxonomic and character sampling on inferred hypotheses relating to tree topology, biogeography and morphological evolution. We also identified potential loss of signal in the binning of morphological characters and tested the impact of parameterisation on divergence date estimation. Our results highlight the importance of securing sufficient taxon sampling for extant lineages when incorporating fossils and underscore the utility of diverse character sources in accurate placement of fossil terminals. Specifically, we find that fossil placement in this group is influenced by the inclusion of male-based characters and the newly discovered Neotropical ‘Lazarus taxon’.

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Do ecological networks in South African commercial forests benefit grassland birds? A case study of a pine plantation in KwaZulu-Natal

Agriculture Ecosystems & Environment ◽

10.1016/j.agee.2010.01.013 ◽

2010 ◽

Vol 137 (1-2) ◽

pp. 133-142 ◽

Cited By ~ 16

Author(s):

Marisa K. Lipsey ◽

Philip A.R. Hockey

Keyword(s):

South African ◽

Grassland Birds ◽

Ecological Networks ◽

Pine Plantation ◽

Kwazulu Natal

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Distinguishing Biology from Geology in Soft-Tissue Preservation

The Paleontological Society Papers ◽

10.1017/s1089332600002898 ◽

2014 ◽

Vol 20 ◽

pp. 275-288 ◽

Cited By ~ 3

Author(s):

John A. Cunningham ◽

Philip C. J. Donoghue ◽

Stefan Bengtson

Keyword(s):

Soft Tissue ◽

Laser Beam ◽

Evolutionary History ◽

Soft Tissues ◽

Analytical Techniques ◽

Tissue Preservation ◽

Deep Time ◽

X Ray ◽

Soft Tissue Preservation

Knowledge of evolutionary history is based extensively on relatively rare fossils that preserve soft tissues. These fossils record a much greater proportion of anatomy than would be known solely from mineralized remains and provide key data for testing evolutionary hypotheses in deep time. Ironically, however, exceptionally preserved fossils are often among the most contentious because they are difficult to interpret. This is because their morphology has invariably been affected by the processes of decay and diagenesis, meaning that it is often difficult to distinguish preserved biology from artifacts introduced by these processes. Here we describe how a range of analytical techniques can be used to tease apart mineralization that preserves biological structures from unrelated geological mineralization phases. This approach involves using a series of X-ray, ion, electron and laser beam techniques to characterize the texture and chemistry of the different phases so that they can be differentiated in material that is difficult to interpret. This approach is demonstrated using a case study of its application to the study of fossils from the Ediacaran Doushantuo Biota.

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