This post is part of a series: Testing Evolution
I figured out how to test evolution, wrote an evolution simulator, ran it, and listed some testable claims I can make if it’s accurate. Now I’ll list some evidence from biology that shows I’m right – in the long term, evolution is not the main thing that happens: devolution is. This is not a full list. I was able to put this together fairly quickly by looking through a top 10 list of genetic disorders and picking a few that are clearly caused by bad mutations that natural selection doesn’t get rid of. These mutations build up in the gene pool over time, causing devolution. If enough of them build up, they’ll eventually drive all life on earth extinct.
Devolution happens fast enough that you can see it happen
I argue that the available evidence says that unless a genetic engineer figures out how to stop it, devolution in humans will eventually lead to extinction. I also expect that the same goes for all other life on earth. To any who say that evolution will out-pace devolution, I offer this challenge: show that evolution happens faster than devolution, and that it reverses devolution often enough to prevent extinction. The odds are stacked against anyone who tries, because mutation is data corruption. In complex systems like life and software, there are generally far more ways to break something than to improve it.
This doesn’t necessarily mean, though, that we’re all about to die from a mutational meltdown. Depending on how many degenerative mutations we have, and how many we can handle, extinction could be tens of thousands of years away.
However, the observed human mutation rate (56-103 per generation, with a large margin of error) is well above one per person per generation, which is far more than evolution can handle. We’re all mutants, so if each of us gets even one bad mutation, natural selection probably won’t eliminate them all.
But wait a minute, how do I know that genetic diseases that run in human families appear faster than good mutations? Does devolution really happen fast enough to see? Are the genetic diseases that run in human families so rare that it took millions of years for the current ones to develop? No. New “de novo” near-neutral, but still-bad mutations appear all the time. Devolution definitely happens fast enough that we can see it. They’re visible enough that you may even know someone who has a genetic disease that runs in a family, but doesn’t have a family history of it. Given enough time and chance, we won’t evolve into a race of supermen, we’ll devolve into dead men (and women).
Note that not all genetic diseases count as devolution. If a mutation keeps you from having viable offspring, or if it makes you so unlikely to have them that the mutation dies out within a few generations, it’s not devolution. This is because it doesn’t build up in the gene pool. Natural selection gets rid of it. If it doesn’t disappear within a few generations, it’ll spread far enough that odds are that it won’t die out.
Also note that not all mutations count as devolution. Geneticists believe, for instance, that blue eyes are caused by a mutation.
Finally, genetic disease can appear in more than one person, independently. Some genetic diseases can be caused by a huge number of individual mutations. This is one thing that makes them harder to treat. In the case of cystic fibrosis, more than 1800 separate mutations are known to cause it. A therapy or drug that works well on 1 variant might not have any effect on another, even if the symptoms of each are identical. This is also one reason why there are often multiple “flavors” of the same disorder.
Genetic disorders that count as devolution
- Cystic Fibrosis
Cause: a damaged gene makes a defective protein, which makes your mucus too thick.
Before modern medical treatments, few if any reached adulthood. It’s still devolution because the gene for it is recessive. Thus many people are carriers, but don’t have the symptoms themselves. Natural selection doesn’t eliminate it.
- Unusual buildup of mucus
- Unusually salty skin
- Unusually thick mucus, causing a continual cough
- Blocked intestines – your digestive system uses mucus to protect itself from stomach acids
- Huntington’s Disease
Cause: a mutation in the HTT gene, which codes for huntingtin. Biologists don’t currently know what it does. They just know that if it breaks, you get a terrible genetic disease.
Causes steady degeneration of the brain, mind, and coordination. Those who have it often describe it as having ALS, Parkinson’s, and Alzheimer’s at the same time.
Symptoms appear starting between ages 30-50, and people survive with it for 10-25 years. Thus, those with this disease are able to have kids before their symptoms become crippling.
Usually, they’re killed by side-effects, like choking or heart failure, rather than the disease itself.
- Personality changes
- Impaired judgement
- Trouble swallowing
- Muscular Dystrophy (Becker or Duchenne)
Cause: a mutation that breaks the protein dystrophin
Makes people unable to sustain healthy muscles.
- Steady degeneration of muscles, starting in early childhood
- Heart problems
- Sickle Cell Disease
Cause: a mutation in hemoglobin – the protein that carries oxygen and makes blood red
The mutant hemoglobin often deforms red blood cells so they can’t fit into the smallest blood vessels. They then clog these vessels and keep blood from getting to some parts of the body.
Perpetual fatigue, caused by not being able to get enough oxygen
- Random-seeming episodes of pain
When tiny blood vessels get plugged up, it often hurts
- Swollen hands and feet
When tiny blood vessels in the arms, legs, hands, or feet get plugged up, the blood has nowhere to go.
Genetic disorder that doesn’t count as devolution
- Down Syndrome
Cause: a third copy (full or partial) of chromosome 21. This doesn’t count as devolution because few people with down syndrome have kids.
- Mental retardation
- Low muscle tone
- Significantly higher risk of several deformities, such as heart defects and poor hearing
- Clothes-folding dryer
This one’s all over the net, so I’m just giving credit to the one that appeared first in the search results