An Excerpt from Jim Conrad's
NATURALIST NEWSLETTER
of October
28, 2001
issued from the woods just
south of Natchez, Mississippi, USA
The Ladies'-tresses Orchids got me to thinking about how the Orchid Family's fabulous success in producing so many species provides insights into nature's general tendencies. For me, recognizing "nature's general tendencies" is a bit like someone else in our culture searching in the Bible or some other holy book in the hope of understanding "what God's plan is." Here is what the Orchid Family teaches me:
First, in terms of evolution, this most-species-rich family of all is a newcomer. The evolution of living things proceeds more or less like a tree that starts as a single sprout, branches, and then the branches rebranch, and so forth, with the branches growing and rebranching at different speeds and with different degrees of vigor. Earth's first large, land-based plants (plants at the evolutionary tree's roots) reproduced with spores, and they appeared over 400 million years ago. Flowering plants did not come onto the scene until much less than a hundred millions years ago, thus they are situated about 4/5 of the way up the evolutionary tree. Moreover, orchids did not appear among the flowering plants until relatively recently, geologically speaking, so they occupy only an outermost twig of the vast evolutionary tree. Yet this outside twig proliferates new species like none other.
What can we see about orchids that might explain their success? For one thing, orchid flowers have fused "traditional" flower parts (calyx, corolla, stamens, etc.) into very specialized structures favoring an efficient pollination system that no longer relies on powdery pollen. Despite the impression given by flower-shop orchids, most orchid flowers, such as my Ladies'-tresses, are much smaller than flowers of "more primitive" species. Orchid species generally occupy very narrow ecological niches -- they are very, very fussy about where they live. Orchid seeds are nearly microscopic: A single pod may contain thousands of seeds, yet if just one of those seeds manages to germinate and grow into a mature plant the orchid is lucky.
If you think about it, the recent evolution of computers has followed the same path as that taken by orchids -- they are always evolving toward higher efficiency, miniaturization, specialization, proliferation, and as more and more computers join into networks there is consequent loss of importance for the individual... A good topic for a long night's discussion would be how human history and today's societies manifest these very same trends, and what this means to us today.
The orchids also show that nature doesn't put all of Her eggs into one basket. The Magnolia Family is considered to be one of the most primitive among flowering-plant families, yet in this forest around me the magnolias appear to be thriving quite as well as the orchids.
I personally find this last observation tremendously encouraging, for here the forest is telling me that as much as anything Nature loves diversity. In a world where orchids and Silicon-Valley yuppies appear to be poised to inherit the Earth, plodding magnolias still can offer their perfume and simple hermits can smell of woodsmoke.