
Originally Posted by
DBM aka FDS
Problems with “change in allele’s over time yadda yadda” crap… I will make it very easy – an allele is a part of a car. Evolution states we can take a car and make tractor… It’s still a motor vehicle, still has some of the same parts, but is drastically different. An allele is a part of that car and/or tractor… The genes (or chromosome – depending) is the car or tractor. Change in the allele crap is that if we change the tire enough the whole car will change… Well, that’s incorrect, because unless you keep within the “parameters” of the car tire, and let’s say, put on a tractor tires, the car does not work.
No, alleles/genes are the blueprints for how the car is made, not the actual car parts, to use your analogy. And, much like cars or tractors, minor variations are built around the current design, while larger design changes incorporate much larger redesigns.
However, at a certain point, the analogy breaks down because motor-vehicles are not organisms.
How do they explain that? Find anything? Nope… anything stating “Look, here we can see how the allele has changed the whole gene sequence (chromosome) into something else… now we have (Presto Chango’d) stems that will eventually turn into feathers (after a couple mutations through natural selection

) after the allele for hair color (Presto Chango’s) continues to change from brown to blonde… or mutates (Presto Chango’s into something completely different)
Alleles change because there are mutations within the genetic code. Jesus, you've been arguing this for, what, like 4 years now? You should know better.
So, short version because I don't want to waste my time too much.
DNA has four bases: ATCG. A combination composed of three bases makes up a codon, which codes for a specific amino acid, which ribosomes use to construct proteins, which are chains of amino acids.
You change the codon, you change the amino acid (sometimes; the last position in a codon usually doesn't affect which amino acid is used to make a protein), which can change the function of a protein (in varying amounts; sometimes changing a terminal amino acid on a protein will result in no change, some amino acids are very similar to one another and don't produce changes in proteins, while others can cause enormous changes with a single amino acid substitution), which can produce macroscopic changes in development or biochemistry. Depends on which protein is affected and how.
This also makes some genes highly conserved, because if they change, the organism simply dies, while other genes code for proteins that don't do a whole lot and thus can be changed quite frequently and rapidly because they don't kill the organism. The former is something like a growth hormone gene, which can kill an organism during development if it is mutated. An example of the latter is the proteins that code for certain taste-bud receptors that have an intense reaction to certain chemicals.
"There are two novels that can change a bookish fourteen-year old's life: The Lord of the Rings and Atlas Shrugged. One is a childish fantasy that often engenders a lifelong obsession with its unbelievable heroes, leading to an emotionally stunted, socially crippled adulthood, unable to deal with the real world. The other, of course, involves orcs." - John Rogers
Bookmarks