Species and systematics
evolvingthoughts | March 19, 2007
Courtesy of Moselio Schechter's blog Small Things Considered, is a new report, downloadable in PDF, from the National Institutes of Health, together with the American Society for Microbiology, on research into bacteria, entitled Basic Research on Bacteria. The Essential Frontier.
The money quote?
“...research on topics like evolution and ecology has a direct impact on the advancement of human health.”
evolvingthoughts | March 19, 2007
Most historians of evolutionary biology have contended that Darwin did not believe that species were real. Instead, they claim, he believed species were arbitrarily delimited from each other, and the species was nothing more than a more distinct variety. Thus, according to Mayr, Darwin did not attempt to solve the problem of speciation because he did not and--because of his species concept, could not--appreciate that there was a problem to be solved. Since he did not consider the species a distinct natural unit, it was only natural that he did not see the need to explain how species multiply…
evolvingthoughts | March 15, 2007
One of the longstanding problems with fitness landscapes is that they are mostly abstract and arbitrary constructs used for conceptualisation rather than actual explanation. Things have changed. Now a paper in Nature shows that fitness landscapes empirically measured show accessible routes of molecular evolution from one function to another. In particular it's nice to see a comment like this:
The tentative picture emerging from the new results is one that emphasizes the possibilities of continuous optimization by positive selection. Although evolution was clearly constrained, as…
evolvingthoughts | March 14, 2007
Is the plant [Thalictrum lucidum] sufficiently distinct from T. flavum? It seems to me a daughter of time. [Planta, an satis distincta, a T. flavo? Videtur temporis filia. Species plantarum 1753]
"The Daughter of Time" (Josephine Tey)" was also the title of a wonderful detective story.
My new motto: Videtur temporis filia...
[Quoted in Ramsbottom, John. 1938. Linnaeus and the species concept. Proceedings of the Linnean Society of London 150 (192-220): 201.]
evolvingthoughts | March 14, 2007
Carl Linné, or as we know him from his Latinised name, Carolus Linnaeus, turns 300 this year, on May 23rd. And Nature has a series of articles on the famous Swede in this week's edition, as well as a slew of other interesting papers. I don't know, nothing blogworthy comes along for months, and then they hit you with too much to do properly...
OK, there is a piece on his legacy to taxonomy in the age of molecular systematics; one on the role and problems of amateurs in systematics and how they may resolve some of the problems of insufficient professionals; Linnaeus' raccoon named Sjupp (not…
evolvingthoughts | March 11, 2007
I have put a file on my home site that lists as many species definitions, from Aristotle to today, as I can find. It's a work in progress, so if you find any that are significant in the history of biology or the present debate that I have missed, please let me know. In time, this may become a reader published somewhere. [It's a 1.3Mb PDF]
evolvingthoughts | March 10, 2007
This is a repost of a piece I wrote for The Panda's Thumb in March 2004. I add it here to put it in the Basics series.
It is, wrote the Roman poet Horace, fit and proper to die for one's homeland. The word he used for homeland was "patria" (dulce et decorum est pro patria mori), and the word has entered into biology as the suffix for exactly that. Unlike Horace's slogan, though, it applies more to living than dying. It would be nice if we humans could attempt to live for our homelands rather than die for them, but that's another rant for another time.
There are a cluster of terms used…
evolvingthoughts | March 6, 2007
New research indicates that "crabs", or pubic lice, began to evolutionarily diverge after human-leading lineages and gorilla-leading lineages split. As there are very few ways to spread public lice, it suggests that there was some hominid-on-gorilloid action after speciation.
Eww, you might think. But this is to be expected in evolutionary terms. If it wasn't a case involving us or our near relatives, we'd say, "sigh... yet another case of divergent species occasionally doing the nasty". For instance, ducks, which have a deep evolutionary history, will often hybridise. Even if the two…
evolvingthoughts | March 5, 2007
Taxonomy is a science, but its application to classification involves a great deal of human contrivance and ingenuity, in short, of art. In this art there is a leeway for personal taste, even foibles, but there are also canons that help to make some classifications better, more meaningful, more useful than others.
Simpson, George Gaylord. 1961. Principles of animal taxonomy. New York: Columbia University Press, p107.
evolvingthoughts | February 28, 2007
Ignore the incredibly lame credits song. This is a cool video, filmed in Panama by actual ecology students, foot fungus and all...
Click To Play
Biodiversity is all around us! In this video we introduce you to the concept of biodiversity. It is more than just the total number of species, however. It describes diversity at all levels from genetic diversity to ecosystem diversity. Yet we are losing biodiversity. We pose the question, "What can each of us do to help save what is left?"
evolvingthoughts | February 23, 2007
When one is starting in a field for the first time, the choice of textbook is crucial, as it will often set the tone for the rest of one's study. Last year and the year before I helped teach Philosophy of the Life Sciences here, and we used, respectively, one textbook and no textbook. Right now I'm reading a rather marvellous book, that would have set me up years in advance of where I am now, so this got me thinking (it's the job description, you know): what are the textbooks on Philosophy of Biology, and what are their respective merits?
I'm going to ignore the various present and…
evolvingthoughts | February 18, 2007
A paper out in Nature 15 February, uses a novel technique devised by one of the authors, Dan Faith, called Phylogenetic Diversity (PD), to assess the biodiversity and conservation value of endangered species and regions in terms of how unique they are in evolutionary history.
The summary article says this:
When seeking to preserve biodiversity, simply trying to count and protect every species may not be enough. A new study suggests that conservationists should also consider the extent to which the mix of species in an area has the genetic potential to adapt to change.
In the past, many…
evolvingthoughts | February 16, 2007
At last, my grant application is in. I reckon there's about the same amount of work in a grant application as in a good size novel paper, which is to say a paper on a topic you haven't published before. To add to that, I finalised a paper for final submission - which I hope meets the exacting standards of the editors.
So I am able now to work on other stuff, which includes more on Darwin and species concepts. When I began this, I hadn't read David Stamos' Darwin And the Nature of Species, in which most of the source material is covered. Stamos, like me, thinks Darwin was a species realist…
evolvingthoughts | February 11, 2007
One of the ironies of the history of biology is that Darwin did not really explain the origin of new species in The Origin of Species, because he didn’t know how to define a species. [Futuyma 1983: 152]
Comments like Futuyma's have been published in scores of textbooks and repeated ad nauseum. Similar criticisms go back to the 19th century, and in my view, they are totally wrong.
Charles Darwin was a student of some of the best geologists and naturalists in Britain at the time, when geology and natural history were regarded as being similar if not identical topics. When he set off on the…
evolvingthoughts | February 4, 2007
The Biohumanities Project of Paul Griffiths, of which I am a minor part, has a page up of talks and discussions at conferences and workshops, recorded for podcasting. We have just revamped and shifted our podcast page to here. If you want to stay abreast of these, subscribe to our RSS feed.
Some of the crispy goodness: A conference on mechanism and reduction, a conference on the philosophy of ecology, and a conference on evidence based medicine, plus talks on emotion, essentialism and biological hierarchies.
evolvingthoughts | February 2, 2007
Darren Naish has a typically wonderful post up about the evolution of giraffe necks, with the delightful snippet that until 1999 people thought they had fewer neck vertebrae than they do.
I can't add to the biology, so allow me to make a few comments about the role of the giraffe in the history of biology.
In the middle ages, the giraffe was known to most Europeans only by travellers' reports, and from classical times it was called the "cameleopard", as it was thought to be a hybrid between a camel, which was a familiar enough animal, at least to the eastern Mediterranean Europeans, and…
evolvingthoughts | February 2, 2007
Recently, John Lynch mentioned a short passage in a book by historian Peter Dear, called The intelligibility of nature. Dear wrote this:
It is one of the remarkable facts about nineteenth-century natural history that the practices of taxonomists were not thrown into disruption by the eventual publication and acceptance of Darwin's ideas after 1859. Darwin was to rely on taxonomy for much of his argument in Origin of Species, reinterpreting its meaning in terms of the branching theory of descent. He never paused to ask whether the very meaning of the category "species" might have been…
evolvingthoughts | February 2, 2007
Canadian blogger, columnist and science fiction writer Ed Willett has a nice piece on some taxonomic jokes that have a point, entitled Lazarus, Elvis, zombies and Jimmy Hoffa. It's also a column in the Regina Leader-Post, which speaks well of Canadian media.
Willett discusses "Lazarus taxa", which are taxonomic groups that are found , either today or as fossils, long after the first instances become unrecorded in the fossil record. The star example of this is the Coelocanth. He gives a good short introduction to Linnaean systematics.
He mentions also Elvis taxa, which are taxa that look…
evolvingthoughts | January 23, 2007
Species: A term which everybody thinks they understand, but which nobody agrees upon, to denote the "basic units" of groups of biological organisms.
It is sometimes said, or has been said to me, that one ought not know too much about a topic if you are to define it clearly. This is because the expert knows all the many nuances that apply in different conditions, and writes not to the beginner but to the other experts. So I must note here that my thesis and continuing work is on species concepts, and things may get a bit rocky. You've been warned.
First of all I'd like to disagree with…
evolvingthoughts | January 23, 2007
Not Darwin. Not Lamarck. Not the Greeks. A French physicist and mathematician...
Pierre-Louis Moreau de Maupertuis (1678-1759) was an interesting man. He devised what we now know as the principle of least action, and showed that the earth was flattened. Some other things he did, however, changed biology forever.
In 1735, the first edition of Linnaeus' Systema Naturae was published. Linneaus put out at least 13 editions of this in his lifetime, and the famous 10th edition was adopted in the 19th century as the "gold standard" - if Linnaeus named a species, that was its name thereafter…