[Pinklemonade]
Comment posted on September 18th, 2006 at 02:03 PM
by the way, the comparison between evolution and gravity is made frequently, but i dont think this i an apt comparison. we call the theory of gravity a law because not only does it adequately describe the phenomenon we observe, but it is useful and successful in predicting outcomes. it is demonstrably consistent. the theory of evolution does not do this at all. it may adequately describe our archeological and biological observations, but it isnt useful for prediction, nor does it have predictable consistency. so i see a major difference between the two.
[/Pinklemonade]


I'm not a physicist, but I played one at college.

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Gravity is intuitive, as anyone who trips can tell you.

Also, when scientists were figuring out gravity, (Galileo, and later Newton w/ his laws of motion) they had the benefit of two very simple systems to study:

The earth, which is so damn big everything on a human scale just falls down, and the solar system.

w/ the planets: From earth, the planets do weird things. Their movements seem chaotic and random. It took a couple of centuries, a couple of geniuses, a new thought model (heliocentric) and a new math (calculus) to figure out that the sky dance of the wanderers could be boiled down to elliptical orbits and relatively simple equations.

(that's for a *simple* model)

When developing the theory of gravity into a law, the simplicity of these systems (two objects in the falling case, 9 observable objects-- at the time-- in the solar system) gave us a huge advantage.

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Evolution is also observable. We also have a thought-model ("Evolution" is short-hand for that whole conceptual thing) and some math. Let me tell you why it then becomes a tough question:

We don't have 9 observable objects. We have trillions of individuals that are spread out over an unknown number of species and which have cycled through an unknown (but very large) number of generations.

Our time scale isn't a couple of decades (I think Saturn takes 30 years or so to cycle, as observed from earth), we're looking at thousands and millions of years.

The system ('life' as it were) is nowhere near as static as the solar system (where large lumps interact only via a single force over very large distances). Individual units can interact with others in hundreds of ways. While also interacting with the environment. While also undergoing personal change.

We can figure out things that are statistically likely, but not certain. And even when you think you know how it works, well, an asteroid falls in the middle of your argument and kills off the dinosaurs.

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Though I pulled the gravity/evolution analogy for the sake of humor, as you point out there is an incongruity in that argument.

the more apt comparison is to the science of geology.

The time scales are equally large. The interactions are also complex, and exact predictions impossible.

I can't tell you what color the next variation of a particular species of flower will be. I can't predict earthquakes in California, either. (more precisely: "SO, this geology of yours tells you how diamonds are created, and the places they form. Where's my diamond, sucka? Come on, fork one over. 50 carats and up, I don't want the small fry, fool.")

Geology does describe the causes and mechanisms that provide for earthquakes, and evolution is also a descriptive science. The failure of each is in the complexity and chaotic nature of the systems they attempt to explain.

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[Pinklemonade]
Comment posted on September 18th, 2006 at 01:31 PM
i would really like for a very knowledgable scientist with no agenda whatsoever to explain to me the strengths and weaknesses of the evolution model. it has many, many stregths of course. correct me if i am wrong, but isnt one of the weaknesses the lack conclusive evidence of the actual bridge or switch from one species to the next? we have remains of several species which are very similar and which are no longer extant. but can we say beyond speculation that there really was a gradual switch from one species to the next rather than just the presence of more than one similar but utterly distinct species? i honestly dont know, and whenever i try to do some curosry research on it (i havent time or patience to read a scientific book on the matter right now, not to mention i wouldnt be sure which book is trustworthy since this is such a politicized issue) all i can find is information that is heavy on the rhetoric and agenda, so i dont know if what i am getting is the facts, or a selective presentation of the facts.
[/Pinklemonade]

My area of expertise is beer the physical sciences (if you'll forgive the language: "Shit that blows shit up") as opposed to the so-called 'soft' sciences (because the gear isn't nearly as cool-- I mean, a 5mi. diameter particle accelerator; I want one in my back yard) so my understanding of the science behind evolution is not as comprehensive as it should be to answer your question.

Since I've been drinking, and since this is the internet, obviously this is no obstacle to me responding.

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The time-scale involved is *huge*

I can't tell you who half of my great-grandparents were, either. (or any of my 16 great-great-etc. for that matter, and that's only going 100 years of so back)

The fossil record is spotty. Sorry. There's no way to fix that. Currently, some scientists are really looking at DNA (particularly now that we can decode whole genomes) but that's like 'listening' to music by reading the binary code off of a CD. ("oooh, I love this part 0001010100010110111010100...")

You doubt the conclusions; because similar species might be descendants, might be ancestors, might be existing concomitantly, might be unrelated but similar in construction (in the broadest sense: birds, bats, and bumblebees all fly), and might even be broad variations in a single species that only appear to be divergent from the physical evidence. (technically, Chihuahuas and St. Bernards are the same specie. Though before we could get puppies, there are practical considerations...)

The whole thing is too big. For me (YMMV) the basic ideas of

- mutation (species diverging over time because individuals are all different from one another, and even within the context of a 'specie' the differences will add up)
- selection (differences between individuals make a, um, difference)
- heredity (stuff that works for me should also work for my kids)
- & random crap (not just asteroid-precipitated-mass-extinctions, but also geographical isolation, wild mutation-- snakes with two heads, et. al.-- climate change, disease, a sudden fad where lemmings are served as hors d'oeuvres in haut cuisine restaurants...)

add up to a system that makes sense as a whole, if requiring a bit of [*cough*] faith.

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and for the record, the orig. post was a joke. a one liner. (well, with some spite behind it, but still a joke)