valerina

I love the Hitchhiker's Guide to the Galaxy series! It's definately one of my top 5 favorite =)

In response to the whole viruses are living thing. I searched the wikipedia entry for eukaryotes and virus did not appear once. Moreover, when I looked up "virus" in wikipedia they say "Because viruses are dependent on host cells for their replication they are generally not classified as "living"." Also, I looked it up and there are 3 Domains, the Eukaryotes, the Prokaryotes and the Archae and viruses aren't placed into any of these! That means that nearly all scientists feel that they are not truly alive. Viruses don't have nucleases or a way of reproducing between viruses or by themselves, but rather they must be inside another type of cell that is alive in order to reproduce. That's the main reason we don't understand how viruses work, mainly because they aren't alive and frankly anything that isn't alive and still manages to reproduce is quite puzzling. As for the fact that the term "higher" and "lower" aren't used by all evolutionary theorists, its true that hardly any will agree in the way you are taking us to mean it (with evolution having a direction and stuff, even though I don't mean that), but all scientists (but maybe a select few) use it when calling things more complex, even if it isn't the best term.

Thanks for the help with the quoting, I'll try it out soon And yeh, that 'smallest particle stuff' really messes with my mind too

First off, thanks for the welcome guys Okay, I still don't know how to quote someone and get there name to show up, but this is something Scathane said: Anyway, I will agree that it is difficult, perhaps impossible, to compare the complexity of carrots and humans since we agreed that since they branched off from the same evolutionary ancestor long ago, making their traits too different. I mean, in some ways we find it plausible that emotions are a characteristic that might be "more complex" than something a carrot has, like its root system that allows it to suck nutrients out of the ground. However this is like (to borrow an old saying) comparing apples to oranges. But now we get to the question, what really is complexity?? When I learn about complexity of organisms here at the university they describe it as something that can be compared between organisms, and say that the most complex organisms are the species that is the latest derived (newest). http://www.estrellamountain.edu/faculty/farabee/biobk/cladogram_1.gif In this case its the chimp, saying that it is the most recently derived species and thus have the most recently derived traits, which tend to be the most complex. Some examples would be the fact that chimps have emotions because we've seen cases (like Coco and her kitten) whereas we know fish do not form these kinds of things. Similarly, we can say that humans are more advanced than primates because we can look at our communication abilities, compare the tools they use to ours, and things like that. If this does not satisfy the issue of complexity, which I'm sure it might not since I am trying to give you the results of centuries of research in a few paragraphs, then say something. I just wanted to make clear that that's how I meant the term earlier.

While it isn't a perfect guide, scientists can look at the number of chromosomes and chromosome lengths in order to compare the complexity of the organism and determine the number of changes an organism has undergone. In this case, a carrot has 18 chromosomes whereas a human has 46. However, there are a lot of exceptions and thus this cannot be relied upon fully. Many organisms that most will agree are less advanced as humans have more chromosomes than us, such as an amoeba, goldfish and the toucan. Still, this principle can be used as a general guide but definately far from proving the fact. However, something that can be relied upon very heavily is the number of genes an organism has. I think it was you that mentioned before, it is hard to compare something like the human and the carrot since the human didn't evolve directly from the carrot. While we have some evidence to support calling humans more complex, we will just have to wait until the carrot genome project is finished and its DNA is compared to that of humans (it MIGHT be, the project started in 1995 but for the life of me I couldn't find the results anywhere). Still, we can compare things we do know evolved more recently. The human genome has approximately 20,000 genes, whereas the fruit fly has approximately 14,000. Typically the more genes you have, the more advanced characteristics that arise in that organism, making it more complex. If you go even farther back, you find that an organism like yeast only has 6,000 genes. This way of comparing gene number probably does have exceptions, but is much more dependable than the first method. I hope this helped and if anyone can find the number of genes a carrot has, that would really help.