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Comment by exmadscientist | Hacker News Reader

Single-point mutation. I know the author thinks that leaving out that qualifier makes the claim sound cooler, but it doesn't. It makes the claim sound wrong. Because the unqualified claim is wrong. There are a lot more things in this world than single-point mutations.

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Another qualifier: "viable". Every viable single-point mutation. This may seem obvious and covered by the "could exist", but it does mean that for any given base pair you won't necessarily find somebody in the population with a mutation there as the claim would seem to suggest.

What is a single-point mutation?

I beleive this is referring to a single base pair changing in the DNA. SNP (Single Nucleuotide polymorphism)

https://medlineplus.gov/genetics/understanding/genomicresear...

https://en.wikipedia.org/wiki/Single-nucleotide_polymorphism

I think the author took the frequency of changes in SNPs and the human population and figured if the change is "compatable with life" it exists in the human population which is a staggering 8 billion.

There are studies called GWAS (Genome Wide Annotation Studies) where they look at a the genetic sequences of a large group of people and try to figure out if a particular SNP causes a particular issue.

https://medlineplus.gov/genetics/understanding/genomicresear...

This GWAS study for example looked at 5 million genomes to find snps associated with height. "Their analysis revealed 12,111 common single nucleotide polymorphisms (SNPs), or places in the genome where a single letter varies, that were associated with height. "

https://www.broadinstitute.org/news/largest-genome-wide-asso...

An A is replaced by a T, or by a G, or by a C, or vice versa.

The more expansive side of the coin are indels or CNVs (copy number variations), where pieces of genome are replaced by other pieces (ATGCT by ATGCTCTA for example) or just deleted, or where specific pieces are copied a few times. These are far harder to measure using current sequencing technologies; most people still use the ubiquitous Illumina machines which can go up to 300bp, and we know many of those more complex mutations are longer than that.

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