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The truth about `Hobbits'

From pygmies in Indonesia to Pluto's status, scientists must marry ideas with facts.

September 07, 2006|David P. Barash | DAVID P. BARASH, an evolutionary biologist, is professor of psychology at the University of Washington.

'FACTS," according to one of Ronald Reagan's more notorious pronouncements, "are stupid things." In all fairness, Reagan had supposedly meant to say "stubborn." But in any event, facts can certainly be troublesome, especially when they require us to give up a cherished notion.

Remember, for instance, in 2004, when anthropologists announced the discovery of fossil remains of members of the genus Homo on the island of Flores in Indonesia? Named Homo floresiensis and standing barely 3 feet tall, these miniature creatures were said to have been a separate species of human beings, living as recently as 13,000 years ago, hunting pygmy elephants and overlapping Homo sapiens in both time and place.

But now it turns out they may be our same old species after all. A re-analysis of the find -- by other researchers -- suggests that these tiny "Hobbit-like people" may have been normal pygmies of the sort currently living nearby, and thus Homo sapiens just like us. Moreover, one skull -- upon which most of the earlier analysis was based -- probably came from a pathologic individual who suffered from microcephaly.

Darn! I was rooting for Homo floresiensis, just as I still hold out hope -- increasingly forlorn -- for Bigfoot, or Sasquatch, reputed to stomp about in the forests of the Pacific Northwest; for the Abominable Snowman, or yeti, of the Himalayas; and even for Nessie, the legendary monster said to inhabit Scotland's Loch Ness.

The scientific jury is still out on the Hobbit people, which is the really important point. "We are not here concerned with hopes or fears," wrote Charles Darwin at the end of "The Descent of Man," "only with the truth as far as our reason permits us to discover it."

I like diversity: different foods, different cultures and languages, different environments, different people, even -- if reality would permit -- different species of people. But science (and in our daily lives, common sense) demand that we be "reality-based" rather than "faith-based" or "preference-based."

The great Nobel Prize-winning animal behaviorist Konrad Lorenz once quipped that a good scientist should be prepared to discard several cherished ideas every day, before breakfast. Although I don't recall that Lorenz often followed his own advice, it remains a touchstone, and one that doesn't apply only to downcast devotees of Homo floresiensis.

Take Pluto. Or rather, consider the melancholy fact that Pluto -- or at least, Pluto as we have known it -- has just been taken from us. Astronomers have concluded that Pluto no longer warrants being part of the planetary pantheon, belonging instead with a group of several "dwarf planets." Many of us grew up with Pluto, just as many of us were tickled by the notion of Homo floresiensis.

By the same token, many of us also grew up with giraffe necks, as follows: Textbooks consistently proclaimed that they are not merely a giraffe's way of keeping its head above its shoulders, but the iconic example of how to distinguish evolution by natural selection from Jean-Baptiste Lamarck's now-discredited notion of the "inheritance of acquired characteristics."

You remember: Whereas Lamarck would claim that giraffes evolved long necks because their ancestors stretched their heads to reach high-elevation leaves, thereby somehow bequeathing elongated necks to their descendants, Darwinians attributed giraffe anatomy to the consequence of longer-necked individuals leaving more successful offspring than their shorter-necked compatriots.

It now appears, however, that sexual selection may hold the real key to why giraffes have long necks, somewhat displacing the hoary traditional wisdom. More than a decade ago, researchers found that long-necked giraffes don't actually forage much higher in the leafy canopy than do short-necked ones; rather, males with long necks use them effectively as clubs, with which to battle their sexual rivals. And females also prefer to mate with longer-necked males. It is thus at least possible that giraffes have long necks not primarily because the ones so endowed got more to eat, but because they were more successful in defeating and intimidating other giraffes, as well as being found attractive by lady giraffes.

If true, the mechanism is still Darwinian natural selection, with evolution proceeding by differential reproduction of alternative forms, but the details will need to be rethought. Herein lies both the frustration and the glory of science and its reality-based and fact-driven approach. Even if we end up losing a purported long-lost Hobbit cousin, or must wave goodbye to Pluto as a familiar member of the planetary pantheon or to the seemingly settled story about giraffe necks, we can cling confidently to one thing at least: the wisdom of attending to the real world and of keeping an open mind.

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