Ok, this bacteria story is too good not to talk about… a group in Italy have been working a ratchet turned by ecoli bacteria. The ratchet itself is small (check out Figure 1 in the link above), about 45 micro meters across and is designed so that bacteria get trapped when facing one direction,…
I think this is interesting and, I suppose, one could choose to see it as profound: life is divided into eukaryotes (which have a cell nucleus) and prokaryotes (which don’t; these are bacteria and archaea). In eukaryotic cells, such as those in the human body, there is a cell nucleus with DNA, and also lots of different organelles. One of these is the mitochondrion, the cellular power plant, of which there may be one or many in any given cell. Prokaryotic cells have none of these things: no organelles (or at least few and simple ones), no nucleus. The interesting thing is that mitochondria (and also chloroplasts, the organelles responsible for photosynthesis) have their own DNA, and reproduce a little like bacteria. (Mitochondrial DNA is inherited only from the mother; hence Mitochondrial Eve.) This DNA looks suspiciously like the DNA of a certain kind of bacteria.
This suggests what is called the endosymbiotic theory: that around 1.5-2 billion years ago — when eukaryotic cells started showing up — one cell survived endocytosis (getting “eaten” by another cell) and, somehow, gave the host cell a leg up in the evolutionary race. This symbiotic relationship continued, and developed into the eukaryotic cells we see today, with mitochondria, chloroplasts, etc. In other words, one prokaryotic cell ate another, but instead of annihilation, the eaten cell continued life inside the host, leading to the survival of both the host and the parasite; today, the “parasite” is such an integral part of eukaryotic cells that if you take it out, you destroy the cell. All multicellular life (just about, anyway) consists of eukaryotic cells. Without this symbiosis, there would be no humans, no animals, no birds nor fish nor plants.
Tell that to the next person who calls evolution a heartless eat or be eaten world.
Imagine you are James Clerk Maxwell, in 1865, formulating your theory of electricity and magnetism, and writing down your four equations for the first time in history. You write down the terms of these equations based on your experiments with electric batteries, bits of wire, and magnets. (…) You take the values you measured for εo and μo, multiply them together, take the square root, and then take the reciprocal. The answer is a speed, so it has units of speed, in this case metres per second. And the answer is very close to 300,000,000 metres per second. Converted into miles, that’s a tad over 186,000 miles per second. Being James Clerk Maxwell, and a brilliant physicist, you immediately recognise what this number is.
The speed of light. (…)
When you were writing down your equations, you were thinking about electricity and magnetism. Light was the farthest thing from your mind. You had not the slightest clue (and nor did anyone else) that light was related to elecricity or magnetism. But there it is, falling out of your equations.
You realise that you are the first person in all of history to know what light is made of. Can you imagine that feeling?