The number of half-life estimates for each tissue type-taxon combination (hereafter referred to as ‘group’).

<p>Two groups (invertebrate organs and invertebrate blood; indicated by *) were excluded from group-level comparisons due to low sample size.</p><p><sup>1</sup>fishes, reptiles, and amphibians</p><p>The number of half-life estimates for each tissue type-taxon combination (hereafter referred to as ‘group’).</p>