Hacker News Reader

Hacker News

Comment by jameshart | Hacker News Reader

Parent Full thread

jameshart

Weird, since ferns’ fractal growth plan lends itself so well to simple recursion.

Maybe most of the genome is just a long comment explaining why they can’t use recursion.

View on HN

Or maybe the simple growth plan allowed it to accumulate lots of cruft that’s basically doing nothing

We used to think huge amounts of our own genome didn't do anything.

But it is true that huge amounts of our genome don't do anything. There are sequences where the same letter or string repeats thousands of times. There are many copies of things that have accumulated mutations that make them non-functional.

The idea that repeated sequences in certain genomes are non-functional or 'junk' is questionable, as they provide additional encapsulation to chromosomes with cell nuclei (a sort of fault tolerance).[0]

[0]: https://www.sciencedirect.com/science/article/pii/S108495212...

Computer architectures sometimes necessitate no-ops under certain circumstances to facilitate functionality. Even though they're no-ops, they're not useless. To the contrary, they have very specific and required uses, which is why they exist.

Evolution works on integrated systems, not parts. Which goes a long way toward explaining why life doesn't seem to have any single-use components - everything serves multiple purposes. We just don't understand them all yet.

That hasn't changed. It's still ~90% junk.

  Total Essential/Functional (so far) = 8.7%
  Total Junk (so far) = 65%
  Unknown (probably mostly junk) = 26.3%

  https://sandwalk.blogspot.com/2011/05/whats-in-your-genome.html
  https://sandwalk.blogspot.com/2008/02/theme-genomes-junk-dna.html

There's a reason for everything.

There is a reason for all the junk in my drawer, but it is still junk.

In cases like this why don’t they try grow a fern that only has genes with an identified purpose and go from there?

Biology only cares about elegance when it substantially contributes to fitness, otherwise entropy is the natural way of things!

Natural selection leaving review comments: lgtm

:shipit: haha

It’s my (very simplistic and layperson) understanding that the size of an organism’s genome is more correlated to how long it has been evolving, rather than any specific complexity of the organism. Since ferns are one of the oldest organisms known to science, it makes sense that their genome would be relatively large.

I don’t remember when/where I heard this, it may very well be BS.

Reply on news.ycombinator.com