Laws Can’t Bind Us: Species
It seems that you can’t have fun for very long before you need definitions. This is also true when examining the wonderous diversity of nature. I guess it helps people who are so inclined to divide up and get a handle on what is going down in a rigid framework. I am more of a swirly kind of guy, but you got to know what the linear folk know if you are ever going to get traction within the establishment.
One of the greatest hopes of bringing the linear folk to the swirly, non-linear light is speciousity. Species-ness? But not speciousness.
Did I just make that word up?
Traditionally, a species was rigidly defined as a group of organisms who can breed with each other to produce fertile offspring. By implication, these groups cannot breed with other ‘species’.
This worked really well in old school biology. A lion can breed with a lion to produce viable progeny, so lions are a species. A lion cannot do this with a hyena, so they are obviously different species.
However, lions can breed with tigers (giving ligers and tiglons, doesn’t this sound like scientology??), producing progeny that are viable! (And actually really huge http://en.wikipedia.org/wiki/Liger). So tigers and lions cannot be different species according to the old rules, which seems a little silly. And if there is one thing the linear, law folk hate, it is seeming silly!
This is an example using the really big mammals that the biological species definition was based on. Things get weirder and weirder from here on out!
In insects, we are starting to see that things that look exactly the same, down to microscopic levels, are actually different species that do not interbreed, communicate in totally different ways, have different chemical hormones and signals etc. This discovery led to the development of the concept of ‘cryptic species’. Species differentiated by things that we just can’t see.
According to the structures of science, if an idea doesn’t work any more, we either need to modify it to accommodate the new data, or abandon the old idea. You’d’ve thunk that after cryptic species, the old species idea would have been thrown out, at least for smaller animals. Think again; some ideas are too necessary and convenient to fail.
And the problems are even clearer when we consider bacteria.
Bacteria are the ultimate in swirly outlaws. No law can bind them. Bacteria just walk up (I guess they kinda waggle up) to each other and exchange genetic material (the minimalist approach to breeding). They are not ‘speciesist’ or exclusive about this in any way. The Staphylococcus are tapping the Escherichia. It is a mad orgy out there!
And so in this mad orgy, genetic flea market, bacteria are exchanging cool abilities like crazy. One guy has a stall giving away his capacity to live on sulfate. A lady grabs some and gives him the ability to photosynthesize in return! Where does it end? Maybe with bacteria that can do all kinds of cool things when they are mixing with a diverse crowd (as the ‘everything is everywhere’ hypothesis suggests they do!)? But certainly not with a rigid idea of what defines a species.