Hacker News Reader

Comment by LeroyRaz | Hacker News Reader

I can't take seriously the suggestion we should expect chimps and humans to be similar due to the "small" number of DNA base changes.

Tiny genetic difference can make a huge difference to an organism. Their statement is like saying doing something 10 times versus 100000 times should give similar results, because expressing both as text the difference is only 4 characters ("10" v.s. "100000"). There are literally places in the human genome that have that kind of effect, e.g. small substitutions resulting in extra whole functioning vertebrae.

View on HN

Additionally, the notion that the DNA is the sole locus of diversity in organisms is now quite outdated. There is a lot going on epigenetically.

That was the point they made.

In their colorful thought experiment, if all our writing/printing ink faded in short time periods, all recognizable civilization would disappear. Seemingly small changes can result in radical impact.

I am objecting to their initial motivation: it being surprising that "small" DNA changes lead us to be vastly superior to Apes.

They suggest in the disappearing ink thought experiment that this is because the genetic change is sufficient for us to pass some critical threshold (allowing cultural transferences of ideas).

That is a completely different from my complaint. I complain that they subtly mischaracterize how we should think about DNA changes. The number of DNA base substitutions is a pretty meaningless metric in the context they are attempting to use it.

I dont disagree with their argument that there can threshhold changes and that cultural accumilation might be one of them.

Isn’t that what they are saying, after raising the question of how percentage of DNA differences doesn’t account for the profoundness of our developmental and behavior differences?

That a few key DNA changes could account for profound change? So small percentage differences are no barrier to very different results?

Reply on news.ycombinator.com