- Education and Science
How We Evolve and Why We Die
A Theory on Human Evolution
So I'm a former Mormon. I was raised with narrow views on many common concepts like evolution. As I was introduced to evolution in school, my approach was that it was wrong and that I had to endure it with patience and move on like it was just a speedbump. Afterwards, it shook the foundations of my belief because there is so much evidence for it.
Now most scientists will go gather information leading up to their theories. Darwin spent years on the sea and on foot observing the wilderness and drawing diagrams, charting his voyage. He also bred pigeons to help gather data. I have absolutely no way of gathering any more data than what I was taught in school for the two theories in this post. They are simply just theories with no backup evidence.
Going off what I was taught for years on evolution... genetic mutations can sometimes be beneficial, sometimes not. On average, each person has two mutations that aren't occurring in either parent. If the mutation is seriously negative, the fetus auto-aborts. If the mutation is minorly negative, you get people who can survive, but their odds of reproducing are significantly lower than others around them (hemophelia, for example, is survivable but makes living much harder). If the mutation is neutral, like in most people, you won't even be able to tell. If the mutation is positive, your likelihood of reproducing can be higher than others in your population.
You can pass on mutations. Once someone had the mutation for hemophelia, it became part of their genetic makeup that they passed on to their kids. Genetic diseases all started out as mutations.
So how DNA is the blueprint of life is that it encodes for proteins or "polypeptides". These proteins have a particular function. Sometimes the function is to metabolize, other times the function is to build non-protein biochemicals like hemoglobin. Some proteins are designs to reassemble or reshape other proteins. DNA is the original code for those proteins. If DNA is mutated the mutation can change the protein that is encoded by that stretch of DNA. Even if the mutation still encodes for the same protein, sometimes the mutation will change the speed at which the protein is made.
Most people have never heard of "Junk DNA". Most of the DNA in our genome does not encode for anything useful. If it is ever translated into a protein, that protein is usually useless and is just re-desolved into the body. Most proteins have a half-life of deterioration, so if a useless one is produced it won't stick around long. Popular science fiction movies sometimes refer to a Master Being in which the junk DNA has been cropped out of the human genome. James Cameron created the series Dark Angel, in which Jessica Alba plays a hybrid human-cat in which all the junk DNA has been removed. She doesn't have whiskers or anything, but she can run fast and jump high and is exceptionally strong.
My theory of evolution revolves around this junk DNA. I do not think junk DNA should ever be cropped out of the genome. Most mutations that ever occur in our genome occur in the junk DNA. If we cropped all the junk DNA out, all mutations would occur on critical DNA. Most of the mutations that occur in critical DNA is negative, whereas mutations that occur in junk DNA are usually neutral. The odds that a positive mutation will occur in the junk DNA is much higher than the odds of a positive mutation occuring in critical DNA.
Essentially what I'm saying is that if we crop out the junk DNA in the human genome, we will significantly slow down the rate at which mankind is evolving.
Why We Die
This theory ties in a little with the last. To understand what I'm discussing, you got to think of human progress versus the progress of other species. The Red Queen Effect is a term borrowed from Alice in Wonderland to describe how multiple species will evolve together. It essentially describes how the evolution of one species drives the evolution of another species and vice-versa.
I have to give an example of the Red Queen Effect real quick. Take an isolated interaction: rabbits and wolves. Wolves hunt rabbits and many times catch the slowest rabbits. The fast rabbits escape and thus reproduce while the slow rabbits die and don't reproduce. The wolf population has removed the weak and left the strong. Now the slow wolves never catch the rabbits and thus starve and die without reproducing. Starvation has removed the weak wolves and left the strong wolves. Both species essentially have evolved one step. The cycle repeats itself and after many generations the rabbits continue to get faster and faster and so do the wolves. The analogy to Alice in Wonderland is that the faster Alice runs, the faster the Red Queen runs to catch her. Faster rabbits mean faster wolves... you get it, right?
So imagine a Red Queen Effect with humans and other species. Viruses and bacteria mutate rapidly so they'd be the Red Queen that always catches us. But what about our food? What if we had never developed farming techniques and were still hungry all the time? Some potential foods we can't eat because they're poisonous or unpleasant to eat. We could evolve to metabolize those foods. We could evolve to no longer taste spice. We could evolve so that we can get energy out of cellulose (wood). There is room for humans to keep evolving.
My theory on death is that it is necessary for evolution of the population to take place. We've already determined that crossing-over of genetic material is necessary for evolution, so we know that organisms have placed a priority on the rate of evolution. If we don't die, we'd keep our out-of-date genetic material in circulation and thus slow down the rate of evolution. Think of it like software - we have to remove old software to make room for the latest version. Death is thus necessary to ensure the rate of evolution.
If death does not take place, it would be the equivalent of Alice no longer accelerating. The rabbit would not run any faster. The wolf and the Red Queen would eventually catch up.
Other Crazy Related Theories
I like the occasional conspiracy theory. A few that I thought were a bit nuts started making sense after taking genetics classes. So you're probably familiar with the concept that humans evolved from a puddle of ooze. Bacteria evolved, then multi-celled plants evolved, then animals evolved. Reptiles evolved into birds that evolved into mammals. Mammals then evolved into all sorts, including great apes, of which our "Common Ancestor" was one. From there we get other great apes like orangutans, gorillas, and chimpanzees. We also get neanderthals and other human-like apes that are now extinct. "Common Ancestor" is usually in context with the other great apes, but really it depends on how many generations of evolution back you go. That puddle of ooze can be considered the Common Ancestor of all species if that's how far back you go.
But the conspiracy theory of choice doesn't deal with genetics that far back. Probably just a few hundred million years back. If you look from species to species, you notice certain genetic similarities from specie to specie. For example, most mammals have five fingers or five finger-like philanges. Bats have five philanges in their wings. Horses evolved their feet to loose their philanges, but fossils of ancient horses showed they used to have five. Mice have five. Cats have four, with a vestigial philange comparable to our thumb. Same with dogs. We share a lot of common genetic material with other species. You may have heard that we are 98 % identical to most apes and 99.8 % identical to chimpanzees. Other species outside mammals might still have 90-95% identical depending on what you're talking about. The vast majority of mammals have seven cervical vertibrae, including the giraffe. All mammals have four chambers in their heart. All mammals grow hair. All mammals are deuterostomes, which means in embrionic development they develop ass-first when considering their gastrointestinal development.
That small percentage of difference seems to count for a lot. Sometimes a stretch of DNA thousands of base-pairs long has an on-off switch just a few base-pairs in size. A mutation can simply shut off the large gene. A small change that makes such a difference. These biochemicals that operate the on-off switches are called Activators, Promoters, and a few complimentary factors. Two species might have the genes for scales, but in humans the activator has been mutated to no longer work and the gene is thus turned off. Humans thus never express the gene for developing scales. Much of our junk DNA is remnants of ancient genes we inherited from our Common Ancestor, genes that have turned off or "become silent".
One conspiracy theory I heard is that at Area 51, they were doing genetic experiments. No surprise there. It gets more believable. I heard a guy was taken to a hospital with scales growing on his arm, much like a fish. Not believable yet. Later they discovered that he wasn't necessarily having his genes tampered with as much as the activators and promoters. They extracted the activators and promoters from fish in large quantities and rubbed them on his skin like a lotion, causing his own silent genes to suddenly turn on and express in the form of scales on his arm. Suddenly the logic becomes much more believable! Holy shit! Whether it is true is not a big deal in my opinion, with the exception of medical applications.
What if we could benefit from our silent genes tucked away in our junk DNA? What if a poor soul has a genetic disease where the only thing wrong is with his promoters and activators? We could perform therapy on just the activators and promoters to suddenly turn the gene on or turn it up?
I know activator and promoter therapy is already being researched. To say it's being done on our junk DNA is just a conspiracy theory. But what if we could unlock all those silent genes? What would we find in our junk DNA? How would it benefit our species? We might never know because we have laws that classify that research as unethical.