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early development, and that this shared development dif ers markedly
from the early embryonic stages of other large groups of animals such as
with a hardworking and loyal honeybee than with a tousled and uncharis-
matic sea urchin, but the evidence of our shared youthful anatomies says
otherwise.
It is not surprising that right down until the 1960s Garstang's conclu-
sion was rejected by some other anatomists. This is in part because he went
too far, and concluded that vertebrates had sprung from ancient echinoderm
stock. We now know that our common ancestor probably didn't look much
like either modern echinoderms or modern vertebrates. But it is now clear
that he was right about his essential point, that we are indeed closely related
to the echinoderms. A century after Garstang's pioneering studies, the subtle
signs of kinship that he drew from the anatomy of early development were
reinforced by molecular studies. Comparisons between echinoderm and
vertebrate DNA sequences prove our close relationship beyond a doubt.
Figure 12
A leaf scorpionfi sh,
Taeniotus tricanthus
, drifts along the bottom, doing a most
convincing imitation of a dead leaf while waiting for nearby fi sh to be fooled.
