Supplementary material

Table 1. Estimates of species richness for four ecological realms. Estimates of upper and lower bounds in the absence of a central estimate constitute an estimated range. Estimates of upper and lower bounds with a central estimate constitute a central estimate with confidence intervals. See sources for additional detail.

Estimate (millions of species)
Realm / Lower / Central / Upper / Source
Coral reefs / 0.62 / 5.06* / 9.5 / 1
Coral reefs / 1.7 / 2.45* / 3.2 / 2
Coral reefs / 1 / 2 / 3 / 3
Coral reefs / 0.49 / 5.23* / 10 / 4
Global / 3 / 3.5* / 4 / 5
Global / 10 / 55* / 100 / 6
Global / 100 / 7
Global / 11.6*** / 8
Global / 5 / 7 / 15 / 9
Global / 14 / 10
Global / 7.4 / 8.7 / 10 / 11
Global / 1.8 / 1.9* / 2 / 12
Global / 2 / 5 / 8 / 13
Marine / 0.5 / 9
Marine / 10 / 14
Marine / 100 / 15
Marine / 5 / 16
Marine / 1.4 / 1.5* / 1.6 / 17
Marine / 2.02 / 2.2 / 2.38 / 11
Marine / 0.7 / 0.85* / 1 / 18
Marine / 0.3 / 12
Terrestrial (Insects) / 2.5 / 6.25* / 10 / Sabrowsky1952, in 19
Terrestrial (Arthropods) / 30 / 20
Terrestrial (Arthropods) / 10 / 45* / 80 / 19
Terrestrial / 10 / 21
Terrestrial (Insects) / 3 / 4* / 5 / 22
Terrestrial
(Insects) / 4.9 / 6.6 / 23
Terrestrial (Insects) / 1.84 / 2.21* / 2.57 / 24
Terrestrial (Insects) / 5 / 7.5* / 10 / 25G
Terrestrial (Insects) / 3 / 4.5* / 6 / 9
Terrestrial (Insects) / 8 / 26
Terrestrial (Arthropods) / 6.6 / 27
Terrestrial (Insects) / 2 / 28
Terrestrial (Insects) / 4 / 9
Terrestrial (Arthropods) / 5 / 7.5* / 10 / 29
Terrestrial (Insects) / 8 / 10
Terrestrial (Arthropods) / 3.7 / 30
Terrestrial (Arthropods) / 5.9 / 30
Terrestrial (Insects) / 5 / 5.5* / 6 / 31
Terrestrial (Arthropods) / 3.6 / 6.1 / 11.4 / 32
Terrestrial (Arthropods) / 3.7 / 7.8 / 13.7 / 32
Terrestrial (Arthropods) / 2.9 / 7.8* / 12.7 / 33

*Mid-point interpolated from upper and lower estimates used in analyses but not reported in Figure 1.

**Estimate includes microbes and not included in statistical analyses

*** Estimate does not include 1.4 million estimated virus and bacteria species

Table 2: Summary statistics for least-squares regressions of central estimates and their upper and lower bounds of species richness through time by realm. Data sources for these analyses are presented in the Table 1 above. P denotes the probability of the slope estimates of these regressions.

Realm / Estimate / Sample size / R2 < / P >
Coral reefs / Upper / 4 / 0.06 / 0.77
Central / 4 / 0.03 / 0.82
Lower / 4 / 0.24 / 0.51
Global / Upper / 6 / 0.17 / 0.42
Central / 8 / 0.16 / 0.34
Lower / 6 / 0.09 / 0.57
Marine / Upper / 3 / 0.01 / 0.94
Central / 8 / 0.14 / 0.41
Lower / 3 / 0.04 / 0.87
Terrestrial / Upper / 12 / 0.05 / 0.55
Central / 21 / 0.06 / 0.35
Lower / 12 / 0.09 / 0.39

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