25 May 2010

There is no such place as an inhospitable habitat

What is wrong with the following sentence?

...primates have evolved in inhospitable habitats, both in terms of availability of preferred resources, and the not unrelated facts that plants have evolved myriad chemical and mechanical mechanisms to protect themselves from predators (Lambert, 2007).
No organism can survive indefinitely in an inhospitable habitat. Inhospitable means "unfavorable to life or growth; hostile". For our purposes, we can refine this definition to mean "unfavorable to life or growth of a specific species". Then, obviously, an organism's habitat, in which it has evolved and may still be evolving to survive, can not be inhospitable to the organism. That just doesn't make sense, for if the organism can survive and reproduce indefinitely in a given habitat, then that habitat is, by definition, hospitable to the organism.

Where there are plants, there are plant predators and when plants have predators, they "have evolved myriad chemical and mechanical mechanisms to protect themselves from predators". Does this, therefore, mean that my backyard is an inhospitable habitat for insects, even though there are hundreds of species returning year after year to munch on the plants? The absurdity of the statement that "primates have evolved in inhospitable habitats" should be obvious. Primates have evolved in hospitable habitats. Their habitats may have been hot, dry, without abundant food and with abundant predators, but they were, nevertheless, hospitable.

Is the intertidal an inhospitable habitat? If we follow the cited author's reasoning, it should be, because in the intertidal the sea recedes periodically, exposing everything to the hot sun and the desiccating air and when it returns, it brings back the predators and at the same time messes up the osmotic balances. Yet thousands of species call the intertidal home. Surely, it can't be that inhospitable.

In The Log From the Sea of Cortez, Steinbeck & Ricketts wrote:
It is noteworthy that the animals, rather than deserting such beaten shores for the safe cove and protected pools, simply increase their toughness and fight back at the sea with a kind of joyful survival.
The phrase "inhospitable habitat" is an oxymoron.

Lambert, J. E. 2007. Seasonality, fallback strategies, and natural selection... in P.S. Ungar (ed.) Evolution of the human diet. Oxford University Press.

1 comment:

Susannah (Wanderin' Weeta) said...

"joyful survival". I like that; it so beautifully describes the intertidal zone's inhabitants.

I just fed my marine invertebrates. Such fun to watch the hermits drop whatever they were doing and rush to catch the floating goodies, tentacles waving excitedly.