No Island Fossils
The lack of transitional fossils
Evolutionary theory spent much of its early years
embarassed about the lack of transitional forms in
the fossil record.
This page presents a theory that helps explain why such fossils are
rare.
Islands
Islands are important as crucibles for new species, and it seems
reasonable to expect that much of the world's gradual evolution
has taken place on them.
No Island Fossils
However islands leave relatively few fossils.
Many islands are volcanic - and fossils tend to prefer
to take up residence in sedimentary rocks.
Many other islands are eventually eroded and crumble into the
sea. This must be an extremely common fate of small
islands. Such an island will leave no fossils.
Next, fossils tend to form in sediments in lakes. Islands
are less likely to have lakes in the first place. Many
lakes are high in the mountains - where the ground is
rocky. Islands tend to form from more coastal land.
Islands have large perimeters, and it is easy for
the perimeter to intersect what was once a lake - and thus drain it.
Even for lakes inland, the small scale of an island
may reduce its drainage basin - and fewer animals
will leave bones in smaller lakes.
These facts may help explain the relatively low frequency
of transitional forms in the fossil record.
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