In highschool you’re taught that DNA is a simple sequence of instructions read by machines in the cell (insert a bunch of useless knowledge about RNA). Depending on signalling chemicals in the cell’s environment, the machines follow the DNA code to build proteins that do stuff. I recently learned it’s way more complicated than that:
- Autocrine signalling
- A cell transmits chemical signals that attach to its own chemical receivers
- Post-translational modification
- A cell produces proteins that modify the other completed proteins inside the cell (including prions, which are inheritable via reproductive cells)
- Post-transcriptional regulation
- A cell produces proteins that modify the way other proteins are assembled in the cell
- Chromatin remodeling
- A cell produces proteins that control how the machines access the DNA, including making parts of it inaccessible (probably inheritable)
- Methylation
- A cell produces proteins that make temporary changes to the DNA (by covering in a chemical that blocks the machines, which is totally inheritable)
- “Copying errors“
- Currently believed to be random mutations, I predict that proteins will be discovered that affect how DNA is copied
- Reverse transcription
- Proteins (including retrovirii) in the cell write new genes into the DNA (when these get inherited they’re called endogenous retrovirii)
Most of these mechanisms are very poorly understood and the more research that gets done in them, the more significant they appear to be versus vanilla genetics. This is why the Human Genome Project has failed to give us superpowers.
All this reminds me of a long time ago, when computers were really expensive, programmers would write programs that modify themselves while they ran. They are impossible to read (you can’t just look at the code), and only crazy people could write them, so it is now considered extremely bad programming. In other words, if there is a God, I wouldn’t hire Him.
Tags: evolution, genetics, Programming
[...] a mechanism called genome imprinting: Chromosomes from each parent have different markers added by chromatin remodeling or methylation (together called epigenetics: I get the impression that which mechanism is unknown in almost all [...]