Biologically useful molecules don’t really go away across the history of evolution. Sure, there are evolutionary innovations, but useful molecules will, at most, be minimally tweaked compared to their predecessors. The entire food web is built on this fact. If we didn’t have the same basic makeup as carrots, carrots wouldn’t have nutrtional value. There has to be a common basis for everything in our biosphere; otherwise the idea of eating something and getting nutrition from it would be madness akin to eating rocks and expecting nutrients. Yes, I am aware that there are some nutrients in rocks and there are people who eat them; this is beside the point.

An experiment that exemplifies this was the Woods Hole octopus extacy study. Scientists found that the seratonin transporter pathway in octopuses was very similar to those in humans and wanted to see if it had similar effects to the human seratonin transporter pathway. To test this, they gave octopuses MDMA and put them in a tank together. Instead of crawling away from the other octopus and hiding in the corner (the usual asocial response of an octopus), the ones on the drug came together and hugged. Despite being separated from humans by a half billion years, the octopuses had an almost identical reaction to MDMA.

OKAPUS

the species that was experimented on

For all intents and purposes, this should be a bizarre finding. Our most recent ancestor with the octopuses was a worm. A brainless, extremely simplistic group of worms known as the acorn worms, which first emerged over 500 million years ago during the Cambrian. The human brain is a somewhat monolithic system of nodes tied directly together. On the other hand, the octopus brain (if you can call it a single thing) is a system of nine independent nodes tied together over an internet of nerves running from each of the eight arm-controlling sub-brains to the central donught-shaped center primary brain. Despite this, the protien interactions between neurons has either been preserved for a half billion years or else re-evolved to an effectively identical purpose from some shared baseline.

WORM

fossils of our most recent common ancestor

And yet, my mom still thinks evolution is a fairy tale invented by Satan. We all have our blind spots, I guess.