31 . Octopi , along with some squid and cuttlefish species , routinely edit their RNA sequences to adapt to their environment . This is unusual for two reasons . 1 ) When an organism changes in some fundamental way , it typically starts with a genetic mutation - a change to the DNA . 2 ) Genetic adaptations to the environment usually occur over many generations - not immediately !
32 . Unlike the octopus , humans can not naturally edit their own genes . However , scientists can now turn genes on and off ! Over the past decade , the CRISPR-Cas9 gene editing system has revolutionized genetic engineering , allowing scientists to make targeted changes to DNA . By delivering the Cas9 nuclease enzyme into a cell , the cell ' s genome can be cut at a desired location , allowing existing genes to be removed and / or new ones to be added in vivo .
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33 . Despite the fact that it is a much more simple organism , an amoeba has 200 times more DNA than a human being !
34 . In 1995 , Haemophilus Influenzae became the first self-replicating , freeliving organism to have its genome completely sequenced . In 2002 , scientists decoded the genome of the first mammal – the mouse .
35 . DNA has a half-life of around 521 years . This means that many ancient species can never be cloned back to life , even if samples of their DNA can be recovered from fossils .
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