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Dr_Vesuvius t1_jbochke wrote

Reply to comment by PatrickKieliszek in I just learned that the known shortest DNA in an “organism” is about 1700 base pairs in a certain virus. Is there a minimum amount of “code” required for an organism (or virus) to function in any capacity? by mcbergstedt

Well first we must distinguish between “non-coding” and the pop-science concept of “junk” DNA. While the most interesting thing about DNA is its ability to code for genes, that is not the only thing it does.

Most of our DNA has some kind of function. That could be coding for RNA that isn’t supposed to be transcribed. It could be structural, like telomeres and centromeres. It could be about regulating transcription or replication.

All the same, human DNA is much more prone to accumulating dead genes than bacterial DNA due to our generation time. We can carry around a bunch of pseudogenes or ancient viruses that managed to get themselves added to our genome. Selection pressure is much less and much slower when it takes 20-40 years to reproduce as opposed to 20-40 minutes.

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Mithridates12 t1_jbp6rmn wrote

Off topic, but I really appreciate when people like you who seem to know what they’re talking about share some insights that laymen like myself can understand. Just makes me want to read up on things

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Major_t0Ad t1_jbwx7av wrote

Adding to this awesome answer: ecologically speaking, the investment for offspring is much less dependent on sheer DNA mass for complex organisms than it is for bacteria. Bacteria optimize things unheard of for complex organisms, they have crazy selection pressure.

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