That what happens when you put the algorithms in front of people.
Didn't it cross anyone's mind that such things would be uncovered? Or that it would always "be cool"? Opt-out? Really?
Money and technology before ethics.
But I'm still left with a question. What does "25% similarity" means? I mean, humans have more than 99% in common genes with the Chimpanzee, so is this a specific set of genes or what exactly?
It's 25% similarity within the 1% of variation that makes you... well... you.
The human genome is ~3 billion bases long (haploid), so even looking at that 1%, that's still millions of possible variations. Only close family members will have significant overlap.
What 23andMe measures are single nucleotide polymorphisms (SNPs). These are variations that are known to occur within the general population. For each of these positions, they can tell if you are homozygous (2 copies with the same ACGT), or heterozygous (One copy A, and another T, for example). Once you take all of that SNP data, you can get a good estimate of how closely related you are to another person. If you share the same patterns, you're likely related.
50% similarity would only be possible between a parent and a child. 25% would be likely between half siblings.
I assume it's tracking chromosomes. Humans have 46 chromosomes, and each chromosome is basically a copy of one from our parents, plus some mutations. You can count the average rate of mutation per generation (which is very low, something on the order of 100-200 total mutations in the entire genome), and then count the differences between one chromosome and another chromosome. When comparing genomes for two individuals, you'll get a low number of differences for some chromosomes and a higher number of differences for others.
So when I hear 25% similarity, I'm thinking that it means that 25% of the chromosomes for person A are very similar to chromosomes for person B, and that the remaining chromosomes are not as similar. This is just relative similarity, the overall similarity will be quite high.
You're right about the relative similarity (and that's the key point), wrong about the number of chromosomes being involved in the 25% calculation. It's about the proportion of bases (letters in the sequence) that can differ between two people that actually differ between these two people. See mbreese's comment: https://news.ycombinator.com/item?id=8293159
The switch to opt-out is quite unconscionable but also expected as the company's main motivation here is gathering data and having as much data as possible, regardless of consequences that they cannot be sued over. I'm sure there'll be similar stories in the future.
Well, people are not algorithms but neither they are animals. Conceptions should be better planned or otherwise punished. Nothing worse then raising other guy's child unknowingly (I know article was not about that).
Didn't it cross anyone's mind that such things would be uncovered? Or that it would always "be cool"? Opt-out? Really?
Money and technology before ethics.
But I'm still left with a question. What does "25% similarity" means? I mean, humans have more than 99% in common genes with the Chimpanzee, so is this a specific set of genes or what exactly?