From viruses?

Some say we evolved from viruses. I thought viruses themselves evolve by integrating the DNA of a host into their own DNA, thereby altering it. If viruses were once the only animal thing in existence, how did they evolve if there were no hosts to integrate DNA from?

We certainly did not evolve from modern viruses so it's impossible to use modern viruses in your example. Which answers your question.

However, you may be curious about this question: Did primative life have some viral characteristics that are no longer expressed? Which is totally possible.

__________________

then why did some primitive life remain virus-like, while other primitive life evolved into different life-forms without virus characteristics, since viruses and other life forms at their earliest stages must have had the same sort of surrounding circumstances?

One species of organism(especially ones with such primative characteristics) can't fill up all the possible ecological niches. That coupled with variation among individuals of a population creates selection pressures so that individuals with certain traits become overtime isolated to a niche.

__________________

So...
The earliest animal lifeform, was it's DNA so varied, that all offspring just came up different randomly? And then the most succesful ones survived, depending on what situation they were in?
Did the primordial amoeba contain the future DNA of a deer and a rabbit, or something, or is DNA something that randomly changes over time? But then what makes DNA change? If DNA can change during the lifetime of a creature, like it does in a virus, doesn't that make natural selection rather irrelevant to early lifeforms? Did they all produce by cloning, like bacteria, then why develop other forms of reproduction, what advantage does this have?


why evolve in the first place? why become something else? why not stay an amoeba?

DNA "changes" when it is copied. When a cell replicates itself, it makes a copy of its DNA. However, this copying process is imperfect. Sometimes mistakes are made resulting in the copy of the DNA to be not identical to the original. These mistakes are called "mutations". It is these mutations which give rise to variations in DNA.

__________________
Creationism has not made a single contribution to agriculture, medicine, conservation, forestry, pathology, or any other applied area of biology. Creationism has yielded no classifications, no biogeographies, no underlying mechanisms, no unifying concepts with which to study organisms or life. - Botanical Society of America's Statement on Evolution

Firstly, the last I was aware, the consensus was that viruses evolved long after bacteria. Thus, while simpler, they are actually more modern lifeforms then bacteria are.

Second, I suggest taking the time to educate yourself about evolution. Your questions demonstrate some common misconceptions about evolution and how it works. I'm sorry to say there's no simple answer to what you're asking; in fact, there is no answer because you are asking the wrong questions. Check out Understanding Evolution by CSU Berkeley, one of the top educational sites on the subject.

__________________
On "illegal" immigration:
"Give us your poor, your tired, your huddled masses longing to be free..." -The Statue of Liberty

On the alleged connection between Hitler and Atheism:
"For it was by the Will of God that men were made of a certain bodily shape, were given their natures and their faculties." -Hitler, Mein Kampf, Volume II, Chapter X

On gay marriage (or any other discrimination) and the Bible:
"God has shown me that I should not call any man impure or unclean." -Paul the Apostle, Acts 10:28

Oh alright then. Thankyou for the website and your answers everyone. Perhaps I'm too philosophically minded to comprehend the purpose of evolution. When someone tells me how finches evolve into other, better adapted, finches, yes I can see how that works, it makes sense to me. But why would atoms and molecules, of which everything is made, for some reason all decide to bunch together and create life, dna, and animals, for the sole purpose of creating more life, dna and animals, albeit in slightly different forms, but essentially and eventually all the same molecules that make up everything else in the first place? Is there some law in physics that causes this? Fair enough I can't expect anyone to provide an answer to this question, if they did they'd probably win the noble prize. But to me, for this reason, when I think deeply on it sometimes, it all makes no sense. ?

Evolution doesn't have any purpose/intend. It's simply a natural consequence of imperfect self-replication. Life that replicates more effeciently in an environment with limited resources will over time tend to outcompete life that replicates less efficiently, and with mutations and an ever changing environment life will continue to evolve.

You mention that you understand about the finches. That's a good starting point. As I'm sure you're aware, there wasn't some conscious evolution process that commanded the birds to "change your beaks!". The relatively slow changes were simply a consequence of mutation and differential survival/reproduction.


First I'd like to point out that "decide" is the wrong word to use. For instance would you ask "Why does salt decide to dissolve itself when it comes into contact with water"? Of course not, as there's no conscious process involved when chemicals react with each other.

Secondly, these things didn't just happen in one step as you perhaps unintentionally seem to suggest. Also, it might be a good idea to break your question up into smaller and more specific questions, as you're basically asking a question so broad that it would take evolutionary scientists and entire books to give a fulfilling answer. When you enter a forum with unrealistic demands, you're bound to get disappointed.

Wikipedia has some good articles about the subject, and it might be a good idea to read some first to get a better idea of good, specific questions to pose. Here's an easy to understand general introduction to evolution. Abiogenesis deals with how life first arose. The RNA World hypothesis might be a good starting point if you're curious about how DNA made its entrance. To understand where animals (and the other eukaryotes) come from endosymbiosis was the initial essential step.


You'll probably never get a full answer as scientific theories doesn't make us omniscient. There will always be holes in our knowledge about the world. But the more you learn about the theory, other areas of biology, organic chemistry, and the classic experiments and important studies in evolution, the less confused you'll be, so it always pays off to study.

Peter

Viruses weren't the first animal.

In fact, viruses aren't an animal, they aren't even alive. But that aside, simple unicellular organisms were the first living things, and viruses came later.