~14,400 km across groups at the surface. It is
also positively correlated to within-basin auto-
correlation (rP= 0.56,P= 10−^7 at the surface;
fig. S10C), which measures the tendency for
communities from the same oceanic basin to
be composed of the same assemblages (here-
after referred to as a“basin-based structure”),
and negatively correlated with latitudinal auto-
correlation (rP=−0.49,P= 10−^5 at the surface;
fig. S10E), which measures the tendency for
communities at the same latitude on both sides
of the equator to be composed of the same as-
semblages (hereafter referred to as a“latitude-
based structure”; see materials and methods).
Results are similar at the DCM, although less
596 29 OCTOBER 2021•VOL 374 ISSUE 6567 science.orgSCIENCE
–0.2
–0.1
0.0
0.1
0.2
–0.2 –0.1 0.0 0.1 0.2
30 100 700
Body size (μm)
Chordata
Diplonemida
Collodaria
Dinophyceae
Diversity (#OTUs)
100
1,000
70,000
Mamiellophyceae
Bacillariophyta
Weak biogeographic
structure
Biogeographic axis 1
Biogeographic axis 2
Large-scale,
basin-based biogeo.
Small-scale,latitude-based biogeo.
Strong biogeographic
structure
A
Diplonemida Dinophyceae
Collodaria
Chordata
Bacillariophyta
Mamiellophyceae
B
C
D E
F G
Fig. 2. Biogeographic heterogeneity across major eukaryotic plankton groups.
(A) Principal coordinates analysis of the biogeographic dissimilarity between 70
major plankton groups. Each dot corresponds to the projection of a group onto the
first two axes of variation; dot size varies with the group’s log diversity, and dot color
varies with its log mean body size. The 70 groups cover the full spectra of
biogeographies, from those with weak spatial structure (left) to those organized at
large spatial scale by oceanic basin (top right) or at smaller spatial scale and
according to latitude (bottom right). (BtoG) Surface biogeography of six
representative groups that are labeled in (A). Only the most prevalent assemblages
in each group are shown by using colors that are variations of the group’s color in
Fig. 1B; the remaining assemblages are left in gray. See fig. S5 for additional groups, and
see ( 31 ) for assemblage-by-assemblage representations of the same biogeographies.
RESEARCH | REPORTS