Membranes

Some time around 4 billion years ago, life was first forming here on Earth. One key to this process was having some way to keep some things out of an organism while allowing other things in.

The forming proto-cells formed from lipids, similar to the way soap bubbles form. Some of these proto-cell lipids spontaneously developed a mechanism to do exactly this, by pushing some things in and other things out.

This is the earliest biological membrane, and it was the key that unlocked all of biological complexity. This was an ultra-simple structure, but over billions of years, this in-and-out control panel of the cell gradually evolved from a crude barrier to a more sophisticated filtration system.

The membrane was a crucial step for the wall of the cell itself, but another big step came when one prokaryote (a cell without a nucleus) engulfed another cell in its entirety, just swallowing that cell’s membrane whole. You have to realize that “swallow” is a metaphor here, since no cell around could really eat anything by this point. Instead, the first word I used—engulfed—tells the story more accurately.

These little cells that had been gobbled up became organelles, each powering a different part of the new mega-structure, the eukaryote. Eukaryotes developed another significant trick, too: their membranes folded inward to better protect the molecule that encoded its structure and allowed it to reproduce: DNA. This little swallowing created the nucleus.

This was more like a bubble that ended up inside of another bubble than Godzilla gobbling up terrified humans, but the process gave those cells certain advantages over other cells. They could now survive and reproduce more effectively, so the era of eukaryotes began around 2.7 billion years ago.

If one cell could sort of swallow another cell to become another type of organism, could multiple cells find other ways of working together in order to form a new super-organism? Indeed, this is exactly what happened at least 2 billion years ago.

Some cells could survive better if they clumped together, whether to better defend against predators or to share resources. When you had a little colony of cells, not all cells had to do the same thing. This meant that certain cells could become specialists, like workers in Adam Smith’s pin factory, now capable of vastly more productivity.

In a multicellular organisms, as we humans are properly classified, there can be cells purely focused on movement, while others take care of reproduction. By differentiating between these tasks, the individual cells now within the larger organism can perform all tasks more efficiently than one cell that tries to do be a jack of all trades.

All of this is possible thanks to membranes.

Today, when one company acquires another, there can sometimes be a similar effect. A company that manufactures computer chips might try to purchase another company that designs the chips, for instance. Many of the biggest companies in the world are collections of lots of little organelle-companies.

The concept of the membrane has been used by people in all sorts of ways. Allowing some things into a liquid while preventing others from getting in is a sort of membrane, and a necessary step in brewing beer, one of our oldest beverages.

As technology improved, we’ve seen use case after use case for membranes. Today, we use them to filter our water, separate fossil fuels into component parts, and in the way we feed the world. We develop new medications and figure out new ways to deliver existing ones, and we figure out new building materials that rely on membranes, like Roman concrete.

Today, denizens of the internet are required to use a sort of information membrane. The internet is an absolute fire hose of information, with the ideas and trivia and statistics of human existence all flying around at light speed. You need to know where to look and what to look for.

Not only do we need to keep harmful misinformation out, but we also need to consider our own output. What and how we communicate into the world is a part of what shapes the world, so let’s be sure we’re shaping it into something reasonably good!