Nature Notes

October 19, 2006

A previously unknown species of mouse belonging to the Old World genus Mus was recently found in the mountainous regions of Cyprus. Our common house mouse, Mus musculus, the one so glorified, prettified, and given the power of human speech in all of those Walt Disney movies and Hollywood cartoons, is also from the Old World and a very close cousin of the Cypriot mouse.

The Greeks and Turks have been haggling for generations over the Mediterranean nation. Meanwhile, the new mouse, probably a resident since long before any human resident, went about quietly doing what it had to do to survive, unmindful of the never-ending struggle for supremacy being waged around it.

Scientists are always finding new species, but new mammals are rare: Fewer than one a year is discovered. A new species of bird was recently uncovered in Africa. Many new species of frogs and lizards, collectively called herptiles, are found each year, particularly in Southeast Asia, Oceania, and South America. And the deeper and wider we explore the oceans and remote rivers and lakes, the more new fish species we dredge up, such as the new shark species found a month or two ago in the western Pacific.

While perhaps there are as many as a thousand new vertebrates waiting out there yet to be found, there are thousands upon thousands of unique invertebrates waiting in the wings. The large majority of them are insects, the largest group of animals in the world by far, but there are almost as many new-to-science marine and aquatic invertebrates out there to keep our zoologists going for centuries to come.

The big challenge, of course, is to find them before they're gone. Each year we lose as many species as we find new ones. We only hear about the larger ones; an insect or jellyfish gone extinct does not make the news. The plant kingdom is as rich in species as the animal kingdom, and the higher plants, the ones with leaves and flowers that are the most obvious, are no exception.

While a typical acre of South Fork forest may contain as many as 25 different species of trees, shrubs, and vines - what we call "woodies" - an acre of rain forest in the backwaters of the Amazon has close to a thousand. With so many different plants packed into such a small area, it is understandable why so many have been overlooked in the past and are just now turning up.

Not counting the viruses, bacteria, fungi, and protozoans - the so-called protests - there are at least two million distinct species already cataloged, almost all of them as specimens in museums or living in zoos.

A species is a form of life differing in a number of ways from every other form of life. The most obvious criterion for separating one closely related species from another, say, the Norway rat, Rattus Norvegicus, from the brown rat, Rattus rattus, is the ability of one to interbreed with the other and produce viable young that can also interbreed with one another and produce viable young, and so on, down the line.

Sure, the donkey, Equus asinus, can be interbred with the horse, Equus caballus, to give rise to the mule, but the hybrid produced from this mating is not fertile. Such interbreeding almost never occurs in nature, to wit, in parts of the West where feral donkeys and wild horses share the same range.

We say that in nature one species is reproductively, or genetically, isolated from another. Locally, there are ponds in which spotted salamanders and tiger salamanders breed side by side; they are very closely related members of the same mole salamander genus, Ambystoma, but they never interbreed. Green frogs and bullfrogs are closely related members of the rain frog genus, Rana. There is nary a pond of the hundreds on the South Fork that doesn't have both breeding at the same time, yet they never interbreed. They are reproductively isolated.

Here on eastern Long Island, eight different aster species may be flowering at the same time in the same area; bees and other insects may be intermingling back and forth with members of each species. Undoubtedly some cross-pollinations between species must be occurring, yet when seeds from them germinate, we only find the stiff-leaved aster, calico aster, late-flowering aster, or New York aster coming up, never a late-flowering-New York aster combination, or a combo from one of the other pairs.

Such observations have become one of the founding blocks of the notion of "intelligent design," as opposed to the Darwinian idea of "natural selection."

It's only been 15 years or so that species can be easily typed and separated from each other by comparing the DNA in their chromosomes or other cellular organelles. The DNA of the Cypriot mouse, when matched against that from the house mouse, was shown to be different.

Further DNA testing will show how different the two are. The number of changes is an indication of how long the two species have been separated from each other, in this case geographically separated. The one may have stemmed from the other, or they both may have come from a common ancestor no longer with us. The more unmatched nucleotide pairs, the greater the time of isolation.

As far as physical anthropologists and biologists can determine, there is only one extant human species, and that species is the only surviving such member of the genus Homo since at least 20,000 years ago. All six-billion-plus of us have genomes that are almost identical in every respect.

Barring the presence of unique physical problems and age differences, all six-billion-plus of us can interbreed to beget new humans. East Hampton Bubbies can just as easily breed with Asians or Eskimos and produce viable young as with other Bubbies. In fact, if it weren't for such outbreeding the modern human would be a sorry stock, beset with so many inborn physical and mental frailties and immunological ineptitudes by now that we could almost be wiped from the face of the earth by a single dread disease in a generation's time.

That will never happen. But we could be wiped out by a genetically and culturally fostered disposition, one that is found in very few other animal species and never to the extent it is found and cultivated in us humans. True, neighboring meerkat clans in Africa raid one another, as do some baboon and chimpanzee tribal groups, but only a few if any clan members lose their lives by way of such raids.

Not so with the human species. We've been raiding one another, and viciously so, since we left the Garden of Eden, and before, no doubt. Our internecine strife shows little sign of paling; millions of us the world over are lost to fighting, either directly or indirectly, each year.

It's been going on for millenniums, with little promise of abating. World government, politics, religion, science, education, and medicine practiced in their most modern and progressive forms don't seem to be able to mollify or mitigate this terrible tendency of ours to contend with one another in injurious and harmful ways.

While this warring predisposition, more than our intellect or our language, may have gotten us to the moon, the planets, and beyond, it is the same one that has put us on the threshold of eternal oblivion. The rub is, there doesn't seem to be much we can do to overcome it before it overcomes us.

Perhaps Huxley was right in "Brave New World," but only begrudgingly. A soma a day might just keep us from becoming the youngest species to ever become extinct. We have to do something to stop the killing, but what?


Questions and comments can be sent to Mr. Penny at nature@ehstar.com.