I wasn’t aware that evolutionary theory had anything to say about the ultimate origin of life?
Evolution in less than 10 words:
Individuals vary.
Variation is inherited.
Fittest individuals reproduce more.
Actually, as the person who wrote the OP, I have to say it wasn’t my intention to stifle debate. (Otherwise we’d be in MSPIMS.) I just wanted persons to make their first posts (or, really, just for the first dozen posts or so) based on personal knowledge rather than information refreshed by recourse to reference works. The idea was to elicit mistaken impressions so that others might correct them.
That implies to me as well, by the way, though I don’t think my thoughts on evolutionary theory are as fantastical as Silverstreak’s.
Evolution has jack all to do with the origin of life. Evolution is the scientific explanation for the diversity fo species. There is no scientific theory for the origin of life as I understand it.
Please understand, by the way, that theory means something different in science than it does in common parlance. A scientific theory is an explanation for a given phenomenon that has been rigorously tested in an attempt to disprove it, and, having so far survived such attempts, is currently accepted by the community of the relevant discipline.
And if one of you guys could poke holes in that definition to make it more rigorous, that’d be great.
Rumor, you never heard about the pond scum we are all supposed to be from? Ahhh, it had to be made alive, seems kind of important to explaining all these animals and stuff…if you need a creator for any part of what all has happened then the theory of evolution fails, that is just how it is.
Yeah maybe they do try to lock it out since it would disprove the theory. I know I was similarly told it is stupid to question the steady state theory in 1950’s, even though it did not explain life either. If any theory does not include this info I know it is false by now. I remember so many false things, the craters on the moon were all volcanoes, and on and on. Each time something comes up to disprove it, well just leave it out, say it works fine if we just don’t consider all the facts. Yeah, great science.
“life” doesn’t disprove evolution, guy. it’s a sine qua non of the fucking theory.
- Descendants of an organism have slightly different characteristics from the parent or parents.
- This leads to a diverse population of the organisms.
- Due to limits on food and/or predators, not all members of a population will reproduce.
- The characteristics which favor reproduction will eventually predominate in a population.
- For various reasons, two subpopulations can be isolated. Over time, the change in characteristics as both subpopulations evolve may cause members to be unable to interbreed. This is speciation.
While in our world we are all related, we can imagine evolution happening on two totally unrelated populations. It is still evolution.
Now I can look at the other responses.
Don’t really see what this is for, but here goes: I’m a layman in these matters. What I remember is from high-school science, some documentaries I’ve seen and the excellent book “The Greatest Show on Earth” by Dawkins. Any errors in this post are most probably mine.
I would roughly define evolution as the changing of the characteristics of groups of organisms over time. The theory of evolution states that these changes are due to variance in reproduction (mostly*) and selective pressures of the environment.
The variance in reproduction is partly due to mutations - changes to the genes** themselves due to rare copying errors or other factors - but for sexually reproducing organisms it’s mostly due to the “mixing” of genes from the parents - a child gets two equivalent genes (one from each parent) for most genes. This mixing does not change the genes - you just get a selection out of what’s called the gene pool: an interbreeding population has a bunch of variants for most useful genes, and you get one or two of each when the parents reproduce.
The selective pressures are anything the organism “experiences” during its life that might be influenced by the inherited information (the genes): a gene that increases your metabolism may help you in running faster when hunting/running away, but it’s a liability when food is scarse. Note that for these purposes, other members of the same species do provide selective pressure. Whenever an organism dies before reproducing, that removes one copy of its genes from the gene pool. Whenever an organism has an improved gene set that helps it cope better than its rivals, that increases the copies of those genes. This is called natural selection. Over time, the successful genes “take over” and the unsuccessful ones die out. This means that populations overall adapt to their environment - they change (they may get bigger, or smaller, or evolve different teeth etc).
If for some reason a population (or perhaps more accurately; the gene pool) is split up (does not interbreed) for some time, the selective pressures can drive the two groups in different directions (dropping certain genes from the pool in one group, while exaggerating them or accepting new mutations in the other), which can result in the two groups not even being able to interbreed after some amount of time. This is speciation.
There is overwhelming evidence that all organisms that have so far been researched are related - and the structure of DNA/genes themselves are one of the strongest pieces of that evidence - leading to the theory that all current life on earth evolved by branching and rebranching etc… from a single source species. Meaning we are not just related to the chimpanzee, but also (much more distantly) to the sponge and the potato. See “the tree of life”. How that original species arrived on the planet is not part of the theory of evolution.
- As far as I know, certain single cell organisms can transfer their genes between individuals directly, even across species. So there the story is different. This also means that for those species, their inheritance tree isn’t a tree at all. There are more of these kinds of exceptions to be found.
I could probably go on a bit about the likely evolution of the eye, which is interesting, and some of the evidence for the theory of evolution, which is also interesting but full of hard to remember details.
In any case, for a simple acceptance of evolution pretty much all you need to accept is that reproduction is not perfect and that some inheritable characteristics of a species are better at surviving in their current environment than others. Oh, and that the earth is a LOT more than 10,000 years old.
I also know plenty annoying straw men / misconceptions / misleading creationist arguments, but I get bored by them.
** ETA: genes are the molecules that hold the information that determines how an organism grows. Variances in genes (or additions or deletion of genes) can result in small or dramatic changes in the “final” organism. Genes do not necessarily influence any specific trait - they can have a local effect or influence a bunch of “unrelated” functions or even work only in combination with other genes. Genes are what gets passed on during reproduction - even when that reproduction is just a simple splitting of a cell into two new ones.
Amusing, but it has a fatal flaw. Evolution does not find global optima, only local ones, exactly because nature does not try everything, just a subset of things.
As others have said, evolutionary theory simply isn’t talking about the origin of life itself. It’s talking about the reason we have different species.
Imagine I take a university course in 1st world war poetry. Would you criticise that course if it didn’t talk about the history of the invention of paper? No, because the course isn’t about that.
The very word evolution means ‘change.’ Not ‘how stuff started.’
That’s demonstratively untrue. In computer science there are genetic algorithms that use random changes to the code to become more suited to the task. The code was “created” initially, and a set of rules were specified, but what happens after that is the result of random modifications and the selection of the “best” candidates for the next round of mutations. The end result can not be predicted in advance, and if repeated the program will almost certainly produce a different solution.
How does this relate to evolution? Well God may have created the initial conditions for life and put into place the physical laws governing the universe and then sat back and let it rip. If we look at the evidence God left it is clear that each organism was not created from scratch. We can see the progression of simpler organisms to more complex ones, each one building upon the structure of the previous generations.
One can argue that it is more magnificent to envision a God that put together a set of initial conditions that resulted in man rather than a God that sat down and directed the development of hundreds of thousands of species, most of them becoming dead ends.
It is a sacrilege to ignore the fossil evidence that God has left behind for us to see. The Bible and other sacred books had to be written through fallible men, but the physical evidence was left directly by God. Do you really want to doubt his work?
You think wrong. Now, life began with a self-replicating molecule, like RNA. Viruses reproduce -do you consider them alive or not?
I did that, but I was too busy looking at the watch I found to notice the TV.
When simple cells are created, will you then accept evolution? It will happen.
Here is an analogy about randomness. Say you have a really complicated lock to open. It has 1,000 stage, each with ten numbers, and to open the lock you have to get every number set correctly, in sequence. Think you can do it? With 10**100 combinations, it might approach the complexity of the cell.
But I forgot to mention something. When you get the right number at each stage, you can hear a click. Now the lock is trivially simple to open, since you go through all the ten numbers at each stage, and when you hear a click, move to the next. That’s how life evolved. It didn’t pop out fully formed, but slowly and incrementally changed over time. The random walk of life kept some fairly simple and successful life forms, but also led to complicated ones like whales and us. At each stage there was a species that was successful in its niche and in its time. We are way different from pond scum, but not so different from either chimps or our common ancestor.
BTW, what did you base your response on? Have you ever read an actual book on evolution?
No scientist would ‘lock out’ data that disproves a theory. They’d write a smug paper explaining in great detail why the current theory is erroneous and there’d be huge debates and a mad scramble as every else tries to test the same phenomenon and at the end we either have a stronger current theory or a new current theory. Science is never set in stone. We can never find The Truth. We can only rule out The Untruths. So we have things like The Law of Gravity. For all intents and purposes it appears to accurately predict the effects of gravity on all phenomenon. If someone performs an experiment where the Law of Gravity is unable to make an accurate prediction, then we need to examine the law and the experiment to find the discrepancy. You are more than welcome to disagree with a scientific principle. However, if you’re going to disagree, it would behoove you to have a similarly valid principle that replaces it. God did it is untestable, makes no predictions and is not even about evolution but rather the beginning of life and therefore not within the scope of this thread.
First off, and if you read even the littlest bit of science you’d be aware of this, we have mapped complete genomes for many species and they do indeed show near endless amounts inherited mutations, so again, I have no clue what you’re talking about. Evolution, as in inherited mutations, is absolutely proven and observed so all you denialism is really moot. And evolution in NO WAY posits how life started. That is simple not its purpose. What it does unequivocally show is that all life we have so far examined has common ancestry and that the diversity of life has arisen through evolution. The first life on the planet is the study of abiogenisis. A different subject altogether. It is also idiotic to state that we need to replicate an event to prove that event took place. We would no nothing about anything if applied that criteria to any field of study. So some creator made the stars because we can’t make one? Or do they just not exist because we can’t replicate one? Your argument is childish and better know as the God of Gaps argument. You fill in our gaps in knowledge with your god though it isn’t needed. We’d still be hunter gathers if we took your outlook and applied to science. “Gee, we don’t know how this happened. Well, it must have been God so I’m not going to bother to look into any deeper.” Luckily for us rational thinkers with even an iota of patience the gaps keep getting smaller and smaller.
Silverstreak Wonder, if you want to try to debate against evolutionary theory, please start a new thread. If not, I suggest you read the other posts in this thread. You might learn something about the subject you are discussing. EDIT: I’m also advising all the other posters to let go of this tangent.
Inner, in your post 73, you say no scientist locks out data, then by the last sentence you lock the origin of life right out of it anyway. Kind of funny. Again it shows how if it does not fit, just leave it out.
Well the origin of life is certainly required to go from elements in a pond to living things, I have never seen a piece of iron reproduce itself, so seems like the living process is rather important to the evolution theory. Since it can’t be figured out, well just leave it out like it is not an important fact?
Several others have the same problem, they basically say, well this works if you just ignore what life is and how it came about. How can that be good scientific method? If life fits evolution then prove it does. Otherwise, false theory.
The theory of evolution doesn’t explain the origin of life just like the theory of gravity does not explain the origin of mass.
Anyway, I note that I forgot to mention in my post above that evolutionary speaking, inheritable traits are only relevant to the extent that they influence reproduction. For humans, this means that there has been very little evolutionary pressure to keep most of us alive after 40 or 50 (when historically speaking we’ve done most reproducing and the kids can live on their own), which is part of the explanation why there are all kinds of health problems related to reaching “old age”.
Not to debate, but to correct a factual error - plenty of scientists are looking at the origin of life. It just doesn’t fall under the umbrella of evolution. Please google “abiogenesis” for details.
Let me esplain. No, there is no time - let me sum up:
Natural selection, genetic drift, sexual selection, mutations, DNA & RNA, common descent, speciation, extinction, ontogeny, phylogeny, phenotype, genotype, fitness, constraints, homology, analogy.
I can expound at length on any of those topics, but there’s way too much to go into for a basic summary. If anyone’s ever read anything I’ve written on these boards, they should have an idea what I do / do not know 
Actually, the OP has indicated that the debate is intended; he just wanted to get some initial off-the-cuff understandings into the thread first. I think the “tangent” may be the intention. Can we get a moderator re-eval?