acapellascience
6 HN recommenders · recommended in 10 months, 2017–2026
3:53 · 6.1M views · Sep 23, 2017
A Capella Science parody of Despacito that sings through evolutionary developmental biology, explaining how a single cell becomes a body, including body-axis genes and dormant snake leg DNA. It runs about four minutes.
HN recommends it as an entertaining four-minute introduction to evo-devo that works even for people who dislike the original song.
11 comments from Hacker News
I'll take a shot at trying to explain that to the best of my ability. I'm starting from the point where we have organisms and dna, since nobody knows how exactly abiogenesis happened yet. First, two general points. The most important thing to keep in mind is time. Life has had insane amounts of time. Billions of years. Beyond human comprehension amounts of time. The second most important thing is that complicated != carefully orchestrated or optimal. Life is pretty cool, but it doesn't hold itself to a very high standard. It's the survival of the good enough, and is full of so many random hacks and poor design choices it's insane. Things get easier to accomplish when you lower the standard. Now an attempt at an explanation. Evolution by natural selection works on two principles. First, generation of diversity. Second, selective pressure. DNA can and does mutate frequently. One important type of mutation is a duplication, since it let's you gain new functionality. You make two versions of the same gene, one keeps it's original function, and the other does some new function. This theme of repurposing existing things comes up again and again. Take something you have, make another version of it, change it a bit. If you've worked out how to grow a vertebra as a lizard and want to become a snake, turn off legs amd make more vertebra. Use the same genes, and just modify how you control them. This video ( this video ) is actually pretty good at running through the science behind evoluti
Yup, DNA turned out to not merely be a sequence of triplets telling a dumb matter printer which hard-coded proteins to make - at least according to what little I understand of evolutionary developmental biology[0], DNA is much more like procedural generation in gamedev or demoscene. That is, there's plenty of recipes for various structures and body parts, and then there's lots of DNA that's responsible for conditionally enabling or disabling or modulating those recipes, depending on more DNA that controls when and where and how much to enable them, and then more - a complex network of logic . -- [0] - Didn't get much further than this four-minute intro to the field, but it is a good intro : this video . (EDIT: It's actually the second part of a trio, that starts with a four-minute bottom-up overview of organic chemistry[1], and ends on a three-minute intro to nanotechnology[2]. I recommend the series together for how well it frames humans in relation to other life and universe as a whole.) [1] - [LINK] [2] - [LINK]
> Producing a whole new limb or whatever is way more complicated that we'd like it to be. It isn't that much more complicated, though. Because as it turns out, you don't always have to code for that limb from scratch. You just have to flip a switch. The key phrase here is "evolutionary developmental biology". We've learned that complex life has a lot of Lego-life quality - a lot of DNA codes for signals that enable or disable creation of whole organs at various locations, stages and cadences. A TL;DR in four minutes by A Capella Science: this video . A nice example that video gives is that snakes have DNA coding for legs, it's just turned off. It can be turned on, and a snake will grow legs.
It is, but it is increasing the branching factor by much more than finding all the "good" melodies in 400 years. Here's a good example of music that stands on it own right despite using the melody of despacito: this video - I'm pretty sure that most people at HN will appreciate this one whether they like despacito or not :)
Homeobox genes [0] are relevant when it comes to pretty high level "heads go on that end, butts go on that end" stuff. There's also this parody video of Despacito [1] that may be, er, educationally amusing. [0] [LINK] [1] this video