kmr wrote:Well, I'm still fuzzy on the whole thing too, but as far as I see it, evolutionists tend to have two different ideas.
1) Mutation creates new genes.
2) Mutation changes genes into new genes.
My idea (I'm sure that countless others have come to this conclusion as well) is as such:
1) Mutation cannot create new genes, because mutation by definition is "an inconsistency in genetic code due to natural influence in a creature". In other words, mutation harms or disrupts the genes that already exist.
There are several types of mutations in the genetic code. Remember that DNA codes for information to make proteins. When being replicated and/or transcribed into mRNA, the code can be either changed or made into the incorrect protein. Every three bases in the genetic code are called codons. These codons will match to specific amino acids that, in turn, when connected, will generate a functioning polypeptide. The function of this polypeptide and therefore the proteins rely upon the correct folding due to the sequence of amino acids. If a codon is incorrect, then several things can happened.
1. It can mistakenly be changed to a stop codon, thereby stopping the entire process of protein synthesis, which obviously is horrible.
2. It can simply be changed to another nucleotide base (an A is added to the DNA instead of a G, for instance), which therefore changes the amino acid that is inserted into the polypeptide chain. This can result in changes to the polypeptide chain anywhere from a neutral mutation (the amino acid change doesn't really affect the protein structure) to a bad change to perhaps a good change (the new amino acid perhaps can change the protein to hold onto a substrate better, for instance). In this case, a mutation isn't always dangerous (although very frequently so), sometimes neutral, and rarely better.
3. The worst type of mutation happens in what is called a frameshift mutation. In this case a nucleotide is dropped or inserted into the DNA chain: ATTGGC can become ATTAGGC...which, as you can imagine, will be disastrous since it causes EVERY subsequent codon to be different. THE BOY ATE HIS CAT becomes TAH EBO YAT EHI SCA T... In this case we see that it's not simply one amino acid that is changed but the entire strand, leading to an entirely different amino acid sequence and an entirely different protein.
Case number two offers the best scenario for neutral or possibly beneficial mutations.
2) Mutation wouldn't turn a life form into another by changing its genes alone, firstly because a complex organism obviously has more genes than a bacterium (which mutation doesn't produce), and second because mutation never really (or perhaps one time in ten to the -1000 power) changes one gene into another that works in an organism, instead it harms the organism. Yes, every person has mutations, but those are the mutations that don't make your eyes focus right, or, in rare cases, change the location of your toes to unnatural positions.
Natural selection does happen, but all it is is different individual inheriting different, pre-existing genes from their parents. Research the difference between dominant and recessive genes (probably already know it), but anyways, there are multiple genes for every property (like eye color), some more likely to be inherited than others. Natural selection basically is when an individual gets a less likely (recessive) gene and passes it on to its children, which doesn't often happen that you can tell would make it a different "species". Different types of dogs were generated in this manner, but the basic form of the canine stayed the same, because it is just the same genes being circulated in different ways.
Not really. Natural selection is not working on whether the dominant or recessive allele is passed on to the offspring. It operates solely based on which allele is passed on selectively. In some cases a recessive allele provides for more reproductive fitness and in other cases the dominant allele does. If a parent population contains 60 percent dominant alleles and 40 % recessive alleles but the organisms that contain the recessive alleles reproduce, then the next generation will have more recessive alleles. (and vice versa if the dominant allele provides more selective advantage).
You'd hate my accent Zoe, but I know I'd love yours...
Lol, I hadn't been keeping up with this thread earlier, so I just saw this. Why would Zoe not like your accent? I know the accents vary a lot, depending on the area, and while I love some accents there, others I don't so much. Have you seen that XBOX game Fable? A lot of the accents on there are not very pleasant. You can marry someone in that game, and I picked the same person out twice! I wasn't trying to (her face is hidden), but the accent she has (um . . . you play a guy) is very nice, I guess it would be considered upper class. She says kind-of snooty things sometimes too, LOL. Anyway, you would like our accent?
SoCal? Love it! 
Now now Danny, I don't want to have to hurt you! 
Okay just kidding, but seriously, she doesn't have a southern accent. 
