TABLE 1.

The distribution of relative age of ECOD domains involved in the new and previous bridging theme dataset

Age bin	The number/fraction of domains in the dataset of 2021 MBE	The number/fraction of domains in the dataset of this paper
0–0.2	1 (0.2%)	0 (0.0%)
0.2–0.4	1 (0.2%)	2 (0.4%)
0.4–0.6	0 (0.0%)	4 (0.7%)
0.6–0.8	141 (30.4%)	44 (7.9%)
0.8–1.0	321 (69.2%)	504 (91.0%)

Note: Ancient domains are enriched in both datasets, with only a few domains that are more recent. Age estimation of ECOD domains. Ages are assigned with the dataset from Edwards et al. ²⁸ A relative age of 1.0 and 0.0 represents the oldest and the youngest domain, respectively.

Abbreviation: ECOD, Evolutionary Classification of Domains.