Haekel's Drawings

Apparently someone cut out each of Ernst Haekel's drawing of invertebrates and put them online under a creative commons license.  Awesome!!!

Check out the gallery Here

A Life Without Holidays

This weekend was Valentine's Day, which got me thinking about holidays and other date/ purpose specific celebrations.  I've written previously about my general dislike for obliged gift giving and reciprocation thereof, but this time I think that I'll assail holidays in general.  

Scrooge was taught to keep Christmas in his hearth throughout the year.  The same principal could be applied to any holiday.  If you are in a relationship, keep Valentine's day in your heart throughout the year.  The holiday and the traditions associated with it are there as a reminder to perform acts and displays of affection and devotion, because frankly people forget.  Listening to the Dr. Laura radio show, the majority of callers looking for help are advised to overtly show their lover that they care about them.  That alone seems to resolve tons of relationship issues.  Holidays and their traditions are there as reminders that serve some social function, whether it is to strengthen family bonds (however often it actually works is up in the air) at Thanksgiving, give people an excuse to dress up an express themselves in disguise at halloween, promote altruism at Christmas.

But this is the twenty first century!  Aren't we as a society and as individuals above the necessity of tradition?  Once we know the purpose of the tradition, can't we find a suitable substitute for it that doesn't oblige us to the limitations that having a holiday on a specific date presents us?  If a husband tells his wife that he loves her on their anniversary, it won't make up for not saying it the rest of the year, but not saying it on that day has bigger consequences than not saying it any other day because of the importance of the calendar date, not the sentiment.  Essentially, having the reminder on a specific date, and then associating importance with that date is deleterious to the intent of the holiday.  Celebrating keeps you at status quo while not celebrating costs you something.

If we were to switch to a system where there were year round public reminders of the virtues espoused by our holidays, would people actually apply those virtues more?  Sadly, I doubt it.  People would just learn to ignore the reminders, staying at the status quo all year.  Having a cost associated with not exemplifying the virtue on a certain date reinforces the behavior, even if only for the period when the holiday is actively on our minds.

Sensitivity sensitivity

It occurred to me at a party the other night that the only thing that someone can say to me, that will get under my skin and raise my ire, is to call me sensitive.  

Ontology and Phylogeny

I've just read Conrad's 2008 "Phylogeny and Systematics of Squamata (Reptilia) Based on Morphology" and it has frankly left my head spinning.  What bothers me is that although this is the best attempt so far at figuring out squamate relationships, there is a big difference between the phylogeny that he developed and the one that I think is intuitively good.  I'm not saying that I prefer one evolutionary hypothesis over all others in the face of contradictory evidence, I'm saying that the distribution of characters on the tree is different from how I think a good distribution would look.  

For example, several characters that are given as unambiguous synapomorphies of a major group, are also shared with other major groups.  Iguaniamorpha, as far as I can tell is synonymous with Iguania under Conrad's taxonomy and are defined by what I consider to be mostly bad synapomorphies which include obliteration of the notochordal canal by centrum ossification, procoelous vertebrae, premaxilla fusion and possession of a ventromedial process of the pterygoids.  All of these are shared by some major schleroglossan groups!  Just about every lizard is procoelous.  Gekkotans are the only ones that I can think of that have an unossified notochort, and that is probably due to the highly derived, paedomorphic state of the group rather than an ancestral condition, something that should have been apparent from comparison to Sphenodon sp. as the outgroup.  A fused premaxilla turns up allot throughout squamate evolution: iguanians, varanids, mosasaurs, snakes, dibamus, some skinks, some geckos.  

The ventromedial process of the pterygoid is especially problematic because it not only appears in other major groups, particularly the Scincophidia (tax. nov.) and the anguinae, but it is reversed several times back and forth within the Iguania.  The Chamaeleontiformes, which includes the living acrodont iguanians and several fossil taxa is considered one of the major divisions in iguanians in other analyses has one reversal from the 'ancestral' condition and there is yet another reversal from the chamaeleontiform condition in two fossil taxa within that group.  This happens again later in the Scincophidia.  It supposedly united some derived skinks, dibamids, amphisbaenids and snakes, but dibamids don't actually have it.  This isn't the only character that does this, but I'm using it as the example.  

Intuitively, reversals from the ancestral character state shouldn't go back and forth several times in one lineage.  If it does, then there must be a strong functional correlate to it and it is therefore a highly plastic and probably bad character.  Also, characters like this popping up all over the tree would make it very hard to think of the systematics in terms of a dichotemous key.  I realize that a dichotemous key doesn't actually reflect evolutionary relationships, but if you only have one or two characters that unite big groups, it aught to at least be close or show up at some point in the creatures development.  It works for plants, birds, mammals and just about every really major group, so why not lizards?

The analysis has 363 characters and 222 ingroup taxa, so clearly this isn't a problem that is just going to be solved by throwing more characters or more taxa at it.  So what other options are there?  Character weighting or unidirectional characters?  The snakes with legs are my preferred group for this example but other groups could be used.  In the Conrad analysis, snakes fell out with other legless lizards in a clade supported by characters largely relating to enclosure of the braincase and modification of the palate.  That by itself doesn't really pose a problem except that snakes with legs, some of the oldest known fossil snakes, fall out as derived macrostomatans.  They are legged beasts nested deep within an otherwise legless group.  I find it hard to believe that they either re-evolved seemingly vestigial legs or that every other group independently lost them.  Possession of legs is such a big character that it implies that the polarity of other, more fine detail characters, is wrong.  Do you make leg possession a unidirectional character?  Weight it more than other characters?  Both of these seem wrong since the natural polarity of a character should be supported by the other characters in an analysis.  

The problem of convergence in snakes and legless lizards could be huge.  The uropeltine snakes are a very bizarre group, specialized for a very specific mode of life.  If they are a natural group, one would expect them to come out in a fairly basal position due to the sheer number of characters that they have in common with each other compared to any other member of the snakes.  If there is a single charcter that would, say unite them with Cylindrophis and 5 that unite them with each other, then Cylindrophis might be pulled out and stuck with macrostomatans because of plesiomorphies.  Establishing character polarity in a group is important but difficult, even in groups that you are certain are monophyletic.  The basal split between horned lizards (phrynosomatidae) and all other iguanians seems similar.  You have a very bizarre, highly specialized group, of unquestioned monophyly pulled out into a basal position on the phylogenetic tree.  This kind of thing could be what causes all of the character reversals higher up in the tree.