Wednesday, March 15, 2006

Classifying things....

` In general, why do people have problems classifying objects (much less their own peers)? A lot of it has to do with language and culture, to be sure. The rest, I would think, has to do with the habitual way that people artificially divide and group things.

` Surely you've heard (or even asked) the old question; 'Is a tomato a fruit or a vegetable?' I've heard it numerous times, and yet the answer is so easy to grasp that I am astounded by the sheer number of people who do not know!
` So, to give anyone who doesn't currently know a bit of an informational one-up, I've added a bit of technicality:
` A tomato plant bears flowers. As you probably know, one part of a flower is called a pistil. And part of the pistil is called an ovary, which contains the ovules. After fertilization, the ovaries ripen into fruit and the ovules mature into seeds.
` That's what a fruit is, and this particular fruit is called a tomato.

` Therefore, the fruit of a tomato plant is... well, a fruit.

` It is surprising how many people do not know that. At one point in my life, I read this on a container of vanilla soy milk; 'Vanilla! The bean that's a fruit!' Apparently, what the writer of those words failed to grasp was that all beans are fruit!
` They are filled with seeds, are they not? Same goes for squashes, corn, and peppers - they are all the seed-bearing parts of flowering plants and therefore cannot be anything but fruit!
` On the other hand, leaves (i.e. kale and spinach) roots (such as carrots and potatoes) and stalks (like celery and rhubarb) are obviously not the fruit of the plant and so can be called 'vegetables'.

` Let's review:

` If it contains seeds, it's a fruit. If it's some part of the plant other than the fruit, it's a vegetable. Therefore, cucumbers, being full of seeds, are fruit. Radishes, being the part of the plant that seeks out, obtains and stores nutrients, are not.
` Could it be any simpler?

` Another question that I've heard people ask would be: 'Is Pluto a planet?' Now that is a tough question. It all depends on your definitoin of what constitutes a planet. I suppose we can all agree that a gas giant - such as Jupiter - which does not have enough mass to initiate nuclear fusion, is a planet: Once fusion begins, the object has become a star. (Though, conversely, are burnt-out brown dwarfs really stars?)
` On the small end of the scale, however, it is much harder to draw any lines between small planets and rocks of some type or another.
` The fact is, Pluto is a Kuiper Belt object and could be argued to be a planet, for example, because it is so large. Yet, it is not the smallest Kuiper Belt object!
` There are several other KBOs that are similar to Pluto in size and orbit, and at least one that is much larger. I suppose the question could be 'Can planets be Kuiper Belt Objects?' If so... what's the difference between KBOs that are planets and those that are not? Is it a spherical shape?

` Figure that out and at least you're closer to an answer.

` This is why I prefer biology and taxonomy. It's not quite as arbitrary, at least above the level of interbreeding populations. And classification data can be so accessible - you can just reach out and touch it! For example, vultures, a clade of raptors, look a lot like condors.
` However for decades, biologists suspected that condors (and other New World vultures) are more closely related to storks and herons than they are vultures and eagles.
` Simply by analyzing the DNA of both Old World Vultures and their American Lookalikes, it is abundantly clear that condors and other species like turkey vultures are Ciconiiformes - or at least close relatives - like the more graceful egrets and ibises. (Incidentally, cranes are lookalikes of Ciconiiformes!)
` Of course, this relative ease of classification in biology is due to the fact that there exist fairly unambiguous taxonomic definitions. That is entirely due to the fact of common decent.
` Unfortunately, planets and other giant bodies come to be in a relatively separate and more chaotic manner. Therefore, they can only be classified in terms of what they are formed out of, how much mass they contain, their position, their movement, shape, and other such aspects.
` This is why I prefer biology - things are easier to define. In anatomy, 'fruit' describes the ripe ovary, the part of an Angiosperm that contains seeds. In taxonomy, a condor is clearly a type of Ciconiiform and is definitely not a Raptor, due to the intervention of millions of years of evolution.
` The word 'planet' on the other hand, is more of a traditional word from the ancients rather than a scientific term.

` I admit, I am rambling. Perhaps I shall not ramble as much in about a week or so when I get my own internet connection. I must go now, as I'm rapidly running out of time.

2 comments:

Galtron said...

I for one thought it was a pretty interesting rambling, especially the first part! It all makes sense now... Tomatoes are fruit, and so are green peppers--not because they grow on related plants but because they are both the part of the plant called a fruit!


I must have slept through that part of biology class. But then... so have a lot of other people, evidently, so I don't feel so bad.

S E E Quine said...

` The terminology most commonly used in American culture doesn't help, either.