Re: Evolution of CPs

Robert Beer (
Tue, 6 Jun 1995 12:53:44 -0700 (PDT)

> you have Sarracenia. In the Northwest, you
> have Darlingtonia in a relatively small geographic
> area. Throughout North America, you also have
> many species of Drosera, and some Utrics.

There is definitely evidence that there was once a broader climatic
region that was friendly to Sarraceniaceae, which includes Sarracenia,
Heliamphora, and Darlingtonia. Droseraceae's wide distribution is not
quite so mysterious, since some N. American Droseras (and Sarracenia
purpurea) is still distributed over wide areas, and droseras have made it
to islands such as Hawaii, possibly on a bird. Droseras seem to have an
easier time spreading long distances. It is also known that the
high-elevation habitat of Heliamphora used to cover much larger areas.

> Many scientists have suggested that there was once
> a continent in the middle of the Pacific which some
> call Mu.

Mu, at one time, was connected to North
> America. The CP plant populations of Mu migrated
> across North America when the climate was different.
> the Darlingtonia species became trapped in cool bogs
> in Oregon, mainly due to the uplifting of mountains
> in the region.

Most of N. America was once much cooler and moister at one time, a
evidenced by the former huge range of redwood species, which require cool
moist habitats to thrive. The predecessor of Darlingtonia may have been
much more widespread during this time and survived only in the cool areas
once the rest of the region warmed up. Depending on the timing, the
entrance into the picture of the Cascades is an important factor as
well, as they form a "rain shadow" and areas to the east are hot and arid.
But what does Mu have to do with it?

> U.S. east coast, and U.S. Southeast. The surviving
> Sarracenia species became adapted to the high tropics
> as Heliamphora in South America.

I would expect that the ancient Sarraceniaceae (not Sarracenia species)
originated in an environment closer to that of the Tepuis (Heliamphora
habitat) since the Heliamphora are the list sophisticated of the family,
still much closer to the rolled leaf. Could they have diverged up both
coasts to become Darlingtonia and Sarracenia? The only Sarrracenia in
the Midwest is S. purpurea, which seems to have come by way of the east
coast and across the north. If actual Sarracenia had been so widespread,
one would expect to find some of them in the many wet sphagnum areas in
the cacades and the redwood areas of California.

At this time,
> the Caribbean region experienced a similar collapse
> and upheaval, separated the Drosera species from
> North and South America. The fact that Drosera are
> found across the world suggests that Gondwana and Mu
> were once connected.

Maybe...but with such small seeds, and the fact that Drosera and
Pinguicula are found on many islands, I wouldn't rule out birds as the
carrier. If they could make it to Hawaii, then why couldn't they be
spread around coastal regions and from small island to nearby island?

This explains the spread of
> Nepenthes between Southeast Asia, the Southwest pacific,
> and the Indian subcontinent.

India was much farther south at one time, and later drifted up to collide
with the Asian mainland, probably taking Nepenthes with it.

When the split up of
> Gondwana occurred, Nepenthes had probably made it to
> Australia. One Nepenthes took hold and had to adapt
> to severe local conditions and became Cephalotus.

Whoa there! Cephalotus is a very different plant than Nepenthes, and
seems to be entirely unrelated. Different construction of the trap,
monoecious as opposed to dioecious, and different floral formulas.

> Anyway, you get the picture. It's wonderful flame
> bait, but I think good to speculate on. We're missing
> a lot of information about how these diverse species
> spread and adapted. The similarities between tubular
> species of pitcher plants are too great to ingore.

Parallel evolution is a pretty common phenomenon. One could say the same
about Cactaceae, Euphorbiaceae, and certain Asclepiadaceae as well as
others. They are not genetically related at all though; they do share
conditions which favored such evolutionary phenomena.

> The same goes for Drosera. And the same for Nepenthes
> and Cephalotus. Somewhere, many of these plants have
> a common genetic ancestry and a common point of origin.

The three genera of American pitcher plants, as stated above, are considered
members of one family. But common form or purpose does not necessarily
mean common ancestry. If something evolved once in one area, why could
it not happen elsewhere?

I'm not
> going to claim they're from outer space. But perhaps,
> there was a common land mass from which VFT's originated
> and all that's left of that original habitat is a finger
> in the Cape Fear region.

Possible...but VFT is in the same family as Drosera, and their motion
also results from a growth process, (unlike some other moving plants,
such as Mimosas for example). Aldrovanda also exhibits the same type of
trapping, so VFT isn't all alone in any sense of the word.

There might have been an Atlantean
> continent connection at one time that held many more plant
> species than we now know of.

There may have been, but our own continent and the continents we know
today have undergone tremendous shifts in climate many times throughout
prehistory; if you visited a particular area several times with several
million years in between each time, you would see many different
habitats. Our Pacific Northwest climate is relatively new; there were
much warmer periods where our present species were found only much
farther north, as well as glaciated periods where all of the Puget Sound
region was unde more than a mile of ice. Many plants of farther south may
have existed here at one time; the Siskiyous, where Darlingtonia is
found, is also home to many, many other endemic species. With all this,
who needs another continent?! (And who knows - if there were another
continent, what other families of carnivores could have existed there?)