Naming Nature

The Clash Between Instinct and Science
Carol Kaesuk Yoon

Whatever editor though up that dumb subtitle should be sent back to the mail room for reeducation. There is no clash in this book between science and instinct. Instinct is not even mentioned. What there is, is an interesting discussion of the way that esoteric systems of classifying the plants and animals of the world, used in the in he academic pursuit of biology, have become far removed from the way we, regular people, recognize them.

Yoon, a biology graduate student turned science journalist, calls this ordinary view of the natural world the "umwelt" (oom-velt) which is a German word for the way we, or the different ways other creatures, perceive the world. A creature's umvelt depends on what kind of senses that creature has, where it lives in the world, what it looks for to eat and what eats it. A dog's unwelt, for instance, has a lot to do with how things smell and prominently features squirrels and the postman. In our case, how we think about the world is another major factor.

Naming Nature contains an entertaining history of the study of taxonomy, starting with Carolus Linnaeus, known to his friends as Carl. Linnaeus devised the system, familiar from high school, of dividing life into domain, kingdom, phylum, class, order, family, genus and species. He established the tradition of naming species with two Latin names, the binomial system. Linnaeus' system is an artificial construct which helps us to comprehend the relationships between different plants and animals. Yoon makes the mistake of equating Linnaeus' taxonomy with the taxonomies of any and all cultures, saying that we all organize nature in our minds in the same way, even though she, herself, gives several examples of cultures that classify animals in bizarrely different ways. Her argument for the universality of Linnaeus is weak. It's also beside the point.

As she proceeds with the history of taxonomy Yoons point becomes clear. Just as physics has wandered far from the common sense of Isaac Newton into the far out realms of relativity and quantum mechanics, taxonomy has found, through statistical analysis, DNA matching and cladistics, all of which Yoon talks about in some detail without any MEGLO (My Eyes Glaze Over) effect, that some of the common sense relationships we believe in, among plants and animals, don't really exits. She quite proudly announces the demise of fish as a teaser at the beginning of the book. Her later explanation of this, having to do with the lungfish having characteristics similar to a cow, seems a bit off the wall, but no matter. That salmon I had for dinner was not a fish. I believe her.

Yoon calls for a revival of the umwelt in our daily lives. Don't let those snooty scientists tell you that nature is a strange place inaccessible to ordinary mortals. Go out there with your Peterson's Field Guides and revel in it before it's too late. Good advice. I think I'll shut off my computer now and go outside.

Ed Note: I went back and corrected the spelling of "umvelt." See the comments below.

The Pluto Files

The Rise and Fall of America's Favorite Planet
Neil DeGrasse Tyson

The Pluto Files is a rather tongue in cheek look at the demotion of Pluto from it's status as a planet by the International Astronomical Union, written by the director of the Hayden Planetarium at New York's Museum of Natural History.

In 2000, the freshly renovated Hayden Planetarium, under Tyson's direction, opened a new exhibit showing the relative sizes of the planets - excluding Pluto. The exhibit classified the planets as either Earth like - the inner group or gas giants, the outer group. Pluto, being very small and made mostly of ice, did not fit in either group, and was left out of the exhibit. This led to a large controversy, many angry letters from elementary school students and, eventually, a vote, in 2006 at a gathering of the IAU, to define the term planet in a way that excludes Pluto.

Tyson's reason for leaving Pluto out of the exhibit is that it is not a member of either class of planets, neither a rocky Earth like planet nor a gas giant. How can you have a class of one? he asks. Pluto is a very small object, smaller than our own moon. It's orbit is eccentric, dipping in closer to the sun than Neptune's for one part of each turn around the Sun and veering off from the plane of the ecliptic. Pluto is like a small child running around and between the legs of a group of adults.

Later, as other Pluto like objects have been found in what is now known as the Kuiper belt, named after Dutch astronomer Gerard Kuiper. At least one, Eris, is larger than Pluto. We now have a class of objects with several thousands of examples, of which Pluto and Eris are the largest known members. Are they both planets, then? No because the AIU had voted on a definition of a planet with three criteria: 1. that it orbits a star and not another object 2. That it has enough gravity to give it a spherical shape and 3. That it has cleaned up it's orbital zone of debris. Both Pluto and Eris, and also one Asteroid, Ceres, meet the first two of these criteria, but not the third.

This last criteria is problematical. The Earth is always being struck by meteorites, which are debris in it's orbital zone. Is the Earth not a planet? Just last weekend Jupiter was struck by a large object which has created an Earth sized impact disturbance in it's atmosphere, visible by amateur astronomers, arguably an object not previously cleared from Jupiter's orbital zone. It appears to me that this is an arbitrary criteria, with exceptions being made in order to include, really, any planets at all. Besides, since when is science subject to a vote?

I suggest that the orbit clearing criteria be abandoned as a bad job and be replaced to the requirement that a planet must have an atmosphere. this would restore Pluto to the status of a planet, possible Eris, too, and exclude Ceres. We would then have nine or ten planets and counting. Pluto has been redefined as a dwarf planet. OK, but a dwarf planet is still a planet.