evolution
pharyngula | December 1, 2008Last week's Friday Cephalopod actually has an interesting story behind it. It was taken from a paper that describes the evolutionary radiation of deep-sea cephalopods.
First, a little background in geological history. Antarctica is a special case, in which a major shift in its climate occurred in the last 50 million years. If you look at a map, you'll notice that Antarctica comes very close to the southern tip of South America; 50 million years ago, they were fully connected, and they only separated relatively recently due to continental drift.
When they were connected, South America acted…
pharyngula | December 1, 2008The Atlantic has republished Asa Gray's review of Darwin's Origin from 1860. It's a fascinating read: Asa Gray was a general supporter of Darwin, and the two of them corresponded regularly, and the review is generally positive, pointing out the power of the evidence and the idea. However, Gray is also quite plain about the way the implications of the theory make him very uncomfortable, and you can see him casting about, looking for loopholes.
The prospect of the future, accordingly, is on the whole pleasant and encouraging. It is only the backward glance, the gaze up the long vista of the…
grrlscientist | November 30, 2008tags: Birdbooker Report, bird books, animal books, natural history books, ecology books
"One cannot have too many good bird books"
--Ralph Hoffmann, Birds of the Pacific States (1927).
The Birdbooker Report is a special weekly report of a wide variety of science, nature and behavior books that currently are, or soon will be available for purchase. This report is written by one of my Seattle birding pals and book collector, Ian "Birdbooker" Paulsen, and is edited by me and published here for your information and enjoyment. Below the fold is this week's issue of The Birdbooker Report which…
evolvingthoughts | November 28, 2008
I haven't done much philosophical blogging lately. There are Reasons. I'm preparing to move to Sydney over the next few months (and there may be a period in which I have no laptop too), and trying to catch up on a bunch of projects I have in play and which deserve my attention. Also, there's a stack yay high of books to review. To impress you all and disgust my editors, they include the following:
Books
Sober, Elliott. 2008. Evidence and evolution: the logic behind the science. Cambridge, UK; New York: Cambridge University Press.
This continues Sober's general project of giving a…
pharyngula | November 26, 2008
Now this is an interesting beast. It's a 220 million year old fossil from China of an animal that is distinctly turtle-like. Here's a look at its dorsal side:
a, Skeleton in dorsal view. b, Skull in dorsal view. c, Skull in ventral view. d, Body in dorsal view. Teeth on the upper jaw and palatal elements were scratched out during excavation. Abbreviations: ar, articular; as, astragalus; ca, calcaneum; d, dentary; dep, dorsal process of epiplastron; dsc, dorsal process of scapula; ep, epiplastron; fe, femur; fi, fibula; gpep, gular projection of epiplastron; hu, humerus; hyo, hyoplastron; hyp…
edyong | November 26, 2008 Clad in hard, armoured shells, turtles have a unique body plan unlike that of any other animal. Their shells have clearly served them well and the basic structure has gone largely unchanged since the time of the dinosaurs. But this unchanging nature poses a problem for anyone trying to understand how they evolved and until now, fossil turtles haven't provided any clues. All of them, just like their living descendants, have fully formed two-part shells.
But three stunning new fossils are very different. They belong to the oldest turtle ever discovered, which lived about 220 million years ago…
laelaps | November 26, 2008
"Fighting the Mammoth," from The Rise of Man.
In efforts to understand evolution, identification of transitional forms has been extremely important. Presently the fossil record offers ample evidence of how one type of organism was modified into something distinct, but has not always been so. In the past, development seemed like it might provide clues as to what the ancestors of particular organisms looked like via the "ontogeny recapitulates phylogeny" argument.
Simply put, the concept envisions that during development organisms "replay" their evolution. This was particularly tied to…
oracknows | November 26, 2008Here we go again.
Every so often, one of the--shall we say?--less popular members of our crew of science bloggers, someone who, despite being an academic whose area of expertise is ostensibly science communication, has stepped in it again. I'm referring, of course to Matt Nisbet. Only this time, it's not him lecturing us just on how to combat creationism. No, this time around, he isn't limiting himself to just that, although that is what he made his name doing, around the blogosphere anyway. This time around, he's perturbed at a certain word, a certain term that we skeptics sometimes feel…
pharyngula | November 25, 2008Got an hour? A good way to spend it would be to watch Neil Shubin lecture about digging in the arctic for fossil tetrapods.
I wonder if this is available in high-quality DVD format? I could see using this in the classroom.
oracknows | November 25, 2008As I sat down on the couch in front of the TV last night to do my nightly blogging ritual, trying to tickle the gray matter to come up with the pearls of wisdom or insolence that my readers have come to know and love, I had a fantastic idea for a serious consideration of a question that comes up in the discussion of science and pseudoscience and how to combat pseudoscience. It would be serious and sober. It would be highly relevant to the interests of my readers. It would rival anything I've ever written for this blog before.
I ended up writing this instead. Oh, well, maybe tomorrow. Besides…
awild | November 24, 2008Last week the Howard Hughes Medical Institute announced that they will be funding Danny Reinberg, Shelley Berger, and Juergen Liebig to sequence three ant genomes. Their interest is research on aging, hoping that solving the puzzle of why genetically identical ant nestmates can either live for a year as a worker or twenty as a queen will unlock some clues to aging in our own species.  I think that's a stretch, but whatever. We myrmecologists will be able to probe the ant genomes for plenty of other worthwhile reasons.
Three species were chosen to represent varying levels of caste…
sporte | November 24, 2008Ebola virus has impressed me as creepy ever since I read "The Hot Zone: A Terrifying True Story some years back by Richard Preston. (I guess he has a new book, too, Panic in Level 4: Cannibals, Killer Viruses, and Other Journeys to the Edge of Science but I haven't been in airport for the past couple of weeks, so I haven't read it yet.)
Technorati Tags: blast, phylogenetic trees, Ebola, viruses
Infectious agents that cause diseases with gruesome symptoms really excite those of us with an interest in microbiology. Tara has written about this paper, too, and summarized the details.
I…
evolvingthoughts | November 23, 2008
Sgt Pepper... oops, wrong oeuvre...
On the 24th of November 1859, a green bound book was published. It made something of an impact on the way we think...
Hat tip to Professor Olsen @ Large
razib | November 23, 2008An editorial in The New York Times, Bring Back the Woolly Mammoth?:
No one is quite sure why the woolly mammoths died out toward the end of the last ice age, some 10,000 years ago. Theories include warmer temperatures that gradually displaced the plants on which they fed, overhunting by primitive man, an accumulation of harmful genetic mutations, widespread disease, or an asteroid or comet colliding with Earth and disrupting the climate.
If scientists do bring back a few mammoths, we suspect our warming world won't look any more hospitable than the one that did them in.
A meta-point here is…
grrlscientist | November 23, 2008tags: Birdbooker Report, bird books, animal books, natural history books, ecology books
"One cannot have too many good bird books"
--Ralph Hoffmann, Birds of the Pacific States (1927).
The Birdbooker Report is a special weekly report of a wide variety of science, nature and behavior books that currently are, or soon will be available for purchase. This report is written by one of my Seattle birding pals and book collector, Ian "Birdbooker" Paulsen, and is edited by me and published here for your information and enjoyment. Below the fold is this week's issue of The Birdbooker Report which…
razib | November 21, 2008Gene Regulation in Primates Evolves under Tissue-Specific Selection Pressures:
Regulatory changes have long been hypothesized to play an important role in primate evolution. To identify adaptive regulatory changes in humans, we performed a genome-wide survey for genes in which regulation has likely evolved under natural selection. To do so, we used a multi-species microarray to measure gene expression levels in livers, kidneys, and hearts from six humans, chimpanzees, and rhesus macaques. This comparative gene expression data allowed us to identify a large number of genes, as well as specific…
awild | November 21, 2008 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. …
evolvingthoughts | November 20, 2008
I'm introducing a new category - the Trashcan. This is a term used in systematics to identify a group that comprises "everything else" once you have done the identification of the real groups of some taxonomic grouping.
I will be using the Trashcan to group together all and only those links that have one common property - that they caught my eye. No other property is necessary or sufficient for inclusion. It has no rank, either.*
Under the fold is the Inaugural Trashcan.
Some work on the simplest vision system, of a marine worm, suggests how complex vision got started. Just two cells…
awild | November 18, 2008In the comments, Rob Clack asks:
Iâve just read about Martialis on Pandaâs 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 Iâm missing something.
Rob is referring to this post, going straight to the problem that Martialis seemingly poses for our…
jrosenhouse | November 18, 2008As part of my daily diet of news sites and blog reading I keep an eye on various creationist websites. This is done partly as opposition research. It's always good to know what the crazy people are getting excited about. But it is also because they frequently link to interesting articles I might have overlooked otherwise.
Over at Uncommon Descent, Denyse O'Leary helpfully linked to this article by Carl Zimmer from the November 10 issue of The New York Times. The article discusses recent developments in genetics, and how hey are changing long-held notions of what a gene is. It's…