Most of my recent, brief essay on why islands leave relatively
few fossils is presented below:

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.

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.

On Mar 1, 1:13 am, Tim Tyler cyberspace.org> wrote:

There is a spot in New Mexico where the fossils are supposed to
be from an ancient lagoon in the Pennsylvanian era. The Kinney Brick
Quarry, Late Pennsylvanian, in Central central New Mexico provides a ...

Lorentz wrote:

Caves and mountains represent other types of isolation, though
often do not represent terribly hospitable environments.

Freshwater lakes can be isolation - for fishies.
E.g. the Cichlid fishes of the great lakes.
These would seem to offer relatively good fossil potential.

Glaciation and deserts could also produce isolation.

It is normally the interior - not the exterior of the desert that
is isolated - and again this is not a terribly hospitable environment,
and might not leave too many fossils.

In article darwin.ediacara.org>, Lorentz wrote:

I suspect that you're thinking of the tepuis, which form part of
the watershed between the Amazon and Orinoco basins.

"Tim Tyler" cyberspace.org> wrote in message news:fqas6f$29ls$1@darwin.ediacara.org...

Paul Crowley wrote:

[Re: http://alife.co.uk/essays/no_island_fossils/]

On Mar 8, 9:12 pm, Tim Tyler cyberspace.org> wrote:

I think my point is that all these environments can form pockets
of isolation. Furthermore, these pockets don't have to last millions
of years, just maybe a few thousand. The pocket has to be isolated
just long enough to form a hybridization barrier. Once the subspecies
has formed a hybridization barrier, even a partial hybridization
barrier, it has the potential of becoming a new species and eventually
a new class of animals.
The hybridization barrier in effect becomes a portable island. The
animal is embedded in its pocket of isolation. The pocket will grow
deeper with time. Maybe a hole in the pocket will form, generating a
taxon much higher than species. Even a difference in mating behavior
can start the evolution ball rolling. ...