Fig. 2: Lineage-Through Time (LTT) plots of daisies and grasses.
From: The rise of grasslands is linked to atmospheric CO2 decline in the late Palaeogene
Solid gray lines represent LTT curves derived from time-calibrated phylogenetic trees of a Asteraceae and b Poaceae (calibration scenario #1). Colored boxes depict the name and number of non-sampled (missing) species per clade that we integrated in our empirical taxon sampling. The shape of LTT curves have demonstrated to be a convenient summary metric for diversification diagnostics, particularly when diversification deviates from the expectation of constant rates81,82. However, the distribution of missing species might not be uniform—as it is the case of these angiosperm families—and can severely impact on diversification-rate estimates. Our work shows that the most important increase in diversification rate for both Asteraceae and Poaceae is completely unnoticeable using the LTT analysis, even when calibrated phylogenetic trees include a large number of species.
