My copy arrived from Amazon the day before yesterday. I’ve not given it anything more than a couple cursory thumb-throughs, but I’m immediately left with the impression of schizophrenia.
The bits on social organization, behavior, communication, and levels of selection- mostly Bert Hoelldobler’s sections- seem an engaging and modern review, while the chapters dealing with ant history and evolution- Wilson’s area- are… How do I say this diplomatically? Rubbish.
The past ten years have brought immeasurable advances in our knowledge of ant evolution, both in breadth and detail. Inexplicably, Wilson fails to recognize it. Really. He cites some recent paleontology but next to none of the large and growing body of genetic work. He reproduces the phylogeny of Moreau et al (2006), but the accompanying text reveals that he does not understand its meaning, nor that it can and is being used to connect the vast body of previously disparate natural history tidbits that Wilson himself relates throughout the book. At best, Wilson’s section is charming but irrelevant, at worst it will serve to further confuse a field that is already finding clarity independent of Wilson. We could use a comprehensive reference detailing the great evolutionary story of the ants, but at first glance this isn’t it.
Oh, and the production value is high. It’s a weighty, glossy, attractive book. Lots of illustrations. The sort of thing that on a coffee table is sure to impress, even if you don’t plan on opening it.
I’ll post more detailed comments as I give it a more proper reading.
In the comments, Rob Clack asks:
I’ve just read about Martialis on Panda’s Thumb and have a question. If I interpret it correctly, your cladogram shows Martialis to be the sister group of all living ants. Since it was blind and many living genera are not, that presumably implies that vision evolved independently within modern ants. I would therefore expect there to be some significant differences between modern ant eyes and those of other hymenoptera.
I assume I’m missing something.
Rob is referring to this post, going straight to the problem that Martialis seemingly poses for our understanding of ant evolution. Was the ancestor of all ants blind?
Continue reading →
Dipterist Keith Bayless exposes a pernicious case of media bias:
Six new families of Diptera were described from newly discovered species in the last 6 years! None of these flies received the press coverage given to Martialis. There are a variety of explanations for this, including that
1) The fly descriptions were published in lower profile journals than PNAS
2) Many of the the new fly families evolved more recently than the first ant in the Martialis lineage
3) The level of public and scientific interest in ants inclines them to be better covered or
4) People who study ants are better at public relations.
I think Keith misses an even larger issue. Continue reading →
Martialis heureka Rabeling & Verhaagh 2008
drawing by the inimitable Barrett Klein for PNAS
Most scientific discoveries these days emerge through carefully planned and controlled research programs. Every now and again, though, something unexpected just pops up in a distant tropical jungle. Martialis heureka is a fantastic discovery of that old-fashioned kind. This little ant simply walked up to myrmecologist Christian Rabeling in the Brazilian Amazon. It is not only a new species, but an entirely different sort of ant than anything known before. Continue reading →
This is a graph showing the number of technical publications indexed in PubMed under the search terms “evolution” and “intelligent design”. I threw in a third search term, “biochemistry”, just to give a sense of how evolution sits relative to another large research field. Basically, the graph measures the productivity of a field in terms of scientific publications. In 2007, scientists produced 17 technical publications every day that employed or tested some aspect of evolutionary theory.
See the blue flatline at the bottom? That’s the productivity of intelligent design. It is dead weight.
The point of Expelled seems to be that intelligent design proponents are being treated unfairly. I don’t agree. They’re being treated about as fairly as one would expect for people that have produced no tangible results. If they want equal time in the classroom, they’ll need to put in equal time at the lab bench.
(And what’s with the death spiral of biochemistry 1995-1998? Did all those folks start keywording with proteomics? Can we expect Ben Stein to narrate a movie lamenting the surpression of biochemistry?)
One of the most important collections of South American plants is being shut down. The Utrecht Herbarium in the Netherlands houses nearly 1 million specimens and 10,000 types. When the museum closes we will lose a wealth of knowledge about the flora of a diverse and endangered part of the world.
Read More and Sign the Petition.
Why does this closure bother me?
Public support for biological research is the reason why that field guide on your shelf costs $15.00, instead of the $100 or so you’d be paying if you had to foot the bill for all the research that book is based upon. Our knowledge of the natural world comes in large part from government subsidies such as that supporting the Utrecht Herbarium. There are plenty of other benefits to maintaining natural history collections as well, including giving us abilities to identify and track medical and agriculture pests, to conduct more accurate forensic investigations, and to monitor long-term changes in the landscape.
Speaking personally, my income from photography absolutely depends on having correctly identified insects. That knowledge is directly tied to taxpayer-supported natural history collections. My identifications either come directly from collections (for instance, I put a name on this Apatides beetle by comparing the beetle to specimens in the natural history collection at the University of Arizona), or indirectly through the use of taxonomic keys and guides that are based on collections. This public knowledge creates private profit. I pay taxes back to the government. And through the compounded actions of many thousands of businesses like mine that make use of public biodiversity knowledge, the whole system pays for itself and makes everyone better off. That’s why I find it so shortsighted every time another collection is closed and more taxonomic experts are laid off.
How does a newly speciating ant prevent backcrossing with its parental species? A new study in the journal Evolution by Schwander et al. investigates four hypotheses using the Pogonomyrmex rugosus/barbatus hybrid speciation system, finding support for three of them. Apparently the daughter species maintains its genetic distinctness from a parent species by mating at a different time, mating preferentially with its own species, and by having a much lowered ability to produce viable offspring.
In my opinion, the story of these hybrid harvester ant species is among the most interesting pieces of evolutionary research in the last decade. If you aren’t familiar with it, it’s worth reading up on. An ancient hybridization between two common harvester ant species, P. rugosus and P. barbatus, spun off a pair of daughter species that are each stuck with the odd position of having to mate with the other daughter species in order to produce worker ants. Otherwise, the colonies produce only queens and aren’t viable. Stories like these serve as reminders for just how complicated the origin of species can be.
Source: Schwander, T., Suni, S.S., Helms-Cahan, S., Keller, L. (2008) Mechanisms of Reproductive Isolation Between an Ant Species of Hybrid Origin and One of its Parents. doi:10.1111/j.1558-5646.2008.00387.x
photo: a worker of a hybrid daughter species emerges from her nest at the Southwestern Research Station in Portal, AZ.
The famous Cambrian Explosion- a rapid diversification of animal groups about 550 million years ago- assumes a rather diminished significance when mapped to the full Tree of Life.
update: yes, I made the diagram myself, by modifying this.
Tribolium castaneum - Red Flour Beetle
The genome of the red flour beetle Tribolium castaneum was published today in Nature. This latest insect genome is interesting not for what it says about beetles but for what it says about another model species, the venerable fruit fly. The more we learn about other insect genomes- the honeybee, the mosquito, and now the flour beetle- the more we see that the famed Drosophila fruit fly is an odd little beast. The bee and now the beetle, it turns out, are both rather normal. They share a lot of proteins with mammals, and fish, and other animals we know about. Fruit flies, not so much. While we all understand that the fruit fly has a number of great qualities for lab breeding and chromosome work and blah blah blah fruit flies blah blah blah (sorry, can’t help it), its genome is so very divergent that it becomes hard to know to what we can legitimately apply our immense accumulated knowledge of fruit fly biology, other than other fruit flies. It is an unfortunate choice for a model organism.
Continue reading →