marbled lungfish

Size doesn’t matter

Since genomes are basically instruction books for making organisms, you’d think that complicated organisms (like people) would have larger genomes than other organisms (like plants and simple animals). But it turns out that isn’t necessarily true!

Human beings have roughly 3.2 billion base pairs in our genome, which is about 3.3 Gb of data in every cell. That’s a lot! But it’s nowhere close to the vertebrate with the largest genome: Protopterus aethiopicus, or the marbled lungfish. 

The lungfish has 130 billion base pairs in its genome. Look at that smug face. But she’s still pretty far from the largest confirmed genome. So far, the biggest one that has been found belongs to an organism called Paris japonica.

That’s right, it’s a plant. It’s genome is 150 billion base pairs, which is frankly ridiculous. This is partly because, while animals have pretty strict rules about chromosome numbers, plants don’t really care as much. Paris japonica’s genome is probably allopolyploid - meaning it contains duplicate chromosomes from multiple species. Researchers suspect it is a hybrid of four different species!