Both Separate and Connected. But how?

I love to beat up on taxonomists because they tend to be constitutionally opposite of me. I see taxonomists as the accountants of the biological sciences, obsessed with making up rules out of thin air and trying to make everyone think they were made by God. But, I hate rules.

I’d like to keep talking about that but it is time for the Almanac Section, where I talk about what happened on the ranch this week. I know you don’t want to. You know I don’t want to. But it’s the rules. What are we going to do?

This week, Jonathon and I pruned a hundred foot tall spruce tree next to the house. Why? Cause humans like views. Really, Jonathon pruned it. I hadn’t even finished my discourse on why it should be pruned, using evolutionary science and what not, before he was up there. I was reminded of all the documentaries of hunter gatherers climbing two hundred feet up into trees to get honey.

Similarly, yesterday afternoon I was with Abel-the-two-year old when he picked up a pointy stick that happened to be laying around and started to chase the dogs saying ‘hunt dogs!’ They ran over to the chickens, and the game changed (‘hunt clucks!’) and the chickens ran over to the sheep and goats. This is a good lesson in herd behavior. ‘Hunts baahs! Hunt doats!’ He has a hard time with ‘g’ sounds. Then, ‘Hunt all animals! Hunt all animals!’ as he ran around with his replica Schonengen javelin. This is why the dogs, chickens, and sheep are so crazy around here but it is worth it if it means that Abel has a chance of being sane.

The technological disruption that is tearing apart our ideas of taxonomy also has me licking my chops, cause I never much liked it anyway. Even in the last five years, a pretty substantial body of science has developed showing that organisms that we call distinct species, have been extensively ‘hybridizing.’ These 'interspecific hybrids’ (quotations and over-the-top eye  rolling explained below) are probably very important mechanisms for evolution. This is not just the case with obscure fruit flies and planarian flatworms. It seems that our most charismatic megafauna (bears, big cats, elephants, wolves) are subject to the shifting sands of ‘interspecific hybridization.’ This has led some workers in the field to say that a ‘species used to be defined as populations that could reproduce.’ I am trying to think of a Monty Python skit that is perfect for this moment but I know that if I start searching the internet I might never come back. So I will make up a hypothetical.

There is a table saw that has the tendency to cut off the pinky and ring finger of its users. After studying the issue, the government agency responsible concludes that with a few simple guards and rearrangements, these table saws could be much safer. However, this would require the users to dramatically change the way they have been using the tool for their whole lives. Instead, everyone agrees that it is better to prophylactically remove the pinky and ring finger of all operators so those things don’t get in the way. The needs of the tool, as constructed, take president over the needs of the user.

There is a very good reason to tie the basic building block of taxonomy to ‘reproducability.’ Taxonomists resist for a bad reason, the universally relevant truth that they all have tenure and, what, are they supposed to learn something new? Or worse, scrutinize the closely held ideas that got them in their current position?  They memorized the obscure difference between Planaria simplex and Planaria fontana. It’s what separates them from the Muggles. It would be like Exxon admitting that global warming is a big problem caused by oil, like the Twinkie Corporation admitting that white fluff has no evolutionary analogue in the human diet. It would amount to killing the Golden Goose! No. Give me a break. They’re going to stuff the truth into the old system until it is impossible to understand for anyone but themselves, then go back to trying to get out of committee obligations.

But this is not going to just be an adjustment for academics. The rest of us will have to come to terms with the fact that a coyote is a dwarf wolf. Well, Linneas probably did the dog first, thats going to be a tricky one. Polar bears are white grizzly bears. That wooly mammoths are hairy Columbian mammoths! The last one gave me pause and caused my courage to falter, but I must push on. And this will be more than a habit of the mind. It will have many real world repercussions, think for example, of the Endangered Species Act. It will not be easy. But it will be true.

And that is what has been missing from Taxonomy since its inception, with Ptolomey or Linneas or with whoever. Truth. Hard, fact based, quantitative truth. It has always been the arcane arguments of people labs as to whether this little protrudence on a bone means that this individual is one species and the other is not. As it turns out, those protruedences don't add up to a hill of beans and in fact, many of the populations that we thought were unambiguously different, that no one argued over, were a lot more closely related than they looked. The incentives have always been to have more species cause then the researcher gets to name that species after his girlfriend. We all know that having a deep sea nematode share your name can be a powerful aphrodisiac.

Then you take it up in front of a committee and people vote on it. If other taxonomists think that your protrudence is a pretty good protrudence than they will vote for it and it’s official. It’s a popularity contest. The problem is Truth is not a popularity contest. I know. By definition, I don’t like it anymore than you do.

This is where we need the help of another discipline, made up by myself thirty seconds ago.  Applied Philosophy. We applied philosophers will see this problem as a species of its own. This is part of one of humanity’s oldest problems, deciding where to draw the line. Where to divide one thing from everything.

Words and other symbols are extremely powerful. But like that table saw, they have their dangers. Having made a word, you need to draw a line. These are things in the real world that this word represents, that this word points to. Which means that everything else is different. Is out. This is a point of great responsibility. On the one hand you risk overstating the similarities between the things represented by your new moniker. On the other hand, you risk overstating the differences between that thing and other things.

Our words, if they are to do more good than harm, must cleave as closely as possible to the real contours of the things they are meant to represent. This is where I must take my hat off to the taxonomists and admit that they are right to make arbitrary rules. In this realm, it is important to have uptight rule followers that religiously believe their own rules to be true. You don't want a freewheeler like me in there. The process of fabricating the idea of a ‘thing’ must be understood as both inherently arbitrary and extremely useful. But also fraught with peril.

The problem is, these consumate rule followers haven't followed the rules. Its time to start. As far as taxonomy is concerned, I believe, this means basing our understanding of taxonomy on sexual compatibility. This is one of our rare opportunities to separate something out from the rest of reality with a word and have the reality reflect that symbolic separation. This thing is different, it is distinct, from all other things in the world that do not have this name. When you have a population that can reproduce, those two populations are tied together and will hang as one through evolutionary history. The evidence supports this more and more. However, the instant those two populations cease to be able to reproduce and create viable offspring, then forever those populations are cast apart, drifting through the vast infinite of the future, never again to be reunited.

From there, I would suggest that we use the time of separating major speciation events as the new metric for taxonomic breaks. We could even use the old and rather dilapidated Kingdom, Phyllum, family, etc. system. Or some other words, the words aren’t important, it is the process for deciding on words that is important. If people didn’t want to call the fundamental building block of our taxonomy a ‘species’ I guess that’s fine. We could say that reproducibility is the hallmark of the Genus. But then you would have to discard the idea that the  ‘species’ is all that important, or even based on anything. You’d have to give me a pretty good reason for that.

Then speciation (as defined by reproduction) goes on to inform every other step in the process.  Ten million years of speciation gets you the genus. More than that? Sorry, your out. 50 million years gets you a family, and so on. I have no idea what the right number should be, and the point is, it doesn’t matter, its arbitrary, but if it’s going to be arbitrary it must be uniformly arbitrary. Or it could be based on a certain number of mutations on base pairs, I am not qualified to speak on the details of how it would look. What do I know is that if taxonomic terms are going to have any relevance in the future, they must be based on evolutionary proxies that can be quantified, and on rules that are uniformly applied. Taxonomy needs to be able to tell me, at a glance, how separate any two organisms are. And how connected.

This sounds ultra geeky, and of course it is. But it is also important. Many enormous human problems are fueled, or even completely generated, from such linguistic malpractice. For example, our species, like most mammal species studied so far, has been shaped by the ‘love’ between long-separated populations. The most famous of these are the Neanderthals and the Denisovans. But it seems increasingly clear that the African ‘anatomically modern human,’ previously viewed as the ‘pure’ species, is the result of crosses between populations that were separated for almost as long as Neanderthals and Denisovans. Hang on to your hats when we finding ancient DNA from European and Asian Hominins that predates the most recent interglacial.

We need to call Denisovans and Neanderthals, what they are. Humans. Homo sapiens. If those people are people, then that tells us something about all the humans that are alive today, way more closely related than H. denisova and H. neandertalensis. It tells us that we are definitely all one thing.