Animal of the week: Even nature could find something to cut: the lungfish has a huge amount of useless DNA

A lungfish is a meter long, but its DNA would reach far into space if it were stretched open. Picture: Wikimedia Commons

We live dire times. Everything has to be cut.

So let’s create our eyes on nature. There is certainly all kinds of extra nonsense there too.

Consider, for example, lungfish. It has the longest gene pool in the world, but only a fraction of a percent of it is actually used.

All land animals, including us humans, are descended from an ancient lungfish-like creature that adapted to live on the border between sea and land hundreds of millions of years ago.

But this current lungfish sloth hasn’t had time to evolve into a human or even a badger, despite having so much DNA. Ineffective!

Pari years ago it was found that the American lungfish (The paradox of Lepidosis) has the longest gene pool of all animals.

So it has the most DNA letters i.e. base pairs, the fragments of which then form genes. Genes, on the other hand, control the functioning of cells and the body and code the proteins that make us up.

Lungfish have a whopping 91 billion base pairs. A person has three billion.

However, fish only have 20,000 functional genes, which is the same as humans. The rest of the lungfish’s genetics is probably pure junk, extra “residual code”. A bit like if a thick book had three pages of facts and the rest of nonsense.

The lungfish is a very self-replicating animal. Much of what it inherits is a copy of itself. In a way, it has a biological copier left on it: certain sequences in the fish’s DNA are duplicated and bounce from one place to another.

Scientists calculate that during every ten million years the lungfish’s inheritance has accumulated size as much as the human gene pool.

Printer is apparently still on. Lungfish’s legacy just expands its futility like a bureaucratic administrative bubble. Isn’t it time to do something!

But the tauhka DNA is not harmful to the fish. It swims in the rivers of South America and occasionally rises to the surface to breathe.

When the dry season comes, the lungfish burrows into the mud and secretes a protective mucus layer around itself. It can hibernate there for even years.