evolution
pharyngula | January 4, 2009
Spiders are amazingly sophisticated animals, and probably the premiere complex adaptation of modern spiders is the ability to spin silk. They have multiple internal glands that can produce multiple kinds of silk — webs contain different kinds, from structural strands to adhesive strands, and other kinds are used for spinning egg cases and for wrapping prey — and they are sprayed out through small spigots mounted on swiveling spinnerets, which are modified opisthosomal (abdominal) limbs. Obviously, these detailed features did not spontaneously appear all at once, but had to have evolved…
gregladen | January 4, 2009The following announcement is from Nature.
About a year ago, an Editorial in these pages urged scientists and their institutions to 'spread the word' and highlight reasons why scientists can treat evolution by natural selection as, in effect, an established fact (see Nature 451, 108; 2008).
This week we are following our own prescription. Readers will find at http://www.nature.com/evolutiongems a freely accessible resource for biologists and others who wish to explain to students, friends or loved ones just what is the evidence for evolution by natural selection. Entitled '15 evolutionary…
jrosenhouse | January 3, 2009Continuing with the recent book review theme, allow me to say a few words about The Accidental Mind: How Brain Evolution Has Given Us Love, Memory, Dreams and God, by David J. Linden. Linden is a professor of neuroscience at the Johns Hopkins School of Medicine.
If you have been paying attention to the creationists lately, you know they have been playing the brain card something fierce. It is here, they claim, that the bad ol' materialist paradigm has met its waterloo. Surely so magnificent an organ can not be explained by Darwinian evolution? It just has to be the result of intelligent…
jlynch | January 3, 2009Some of you may already have seen this (for example, PZ has mentioned it), but Nature has put together a short PDF document that gives fifteen lines of "evidence for evolution by natural selection" [here]. Here's the list (stolen from PZ):
The discovery of Indohyus, an ancestor to whales.
The discovery of Tiktaalik, an ancestor to tetrapods.
The origin of feathers revealed in creatures like Epidexipteryx.
The evolution of patterning mechanisms in teeth.
he developmental and evolutionary origin of the vertebrate skeleton.
Speciation driven indirectly by selection in sticklebacks.
Selection…
jlynch | January 3, 2009
Carl Zimmer is presenting a series of posts by Ken Miller in which Miller takes on DI-flack Casey Luskin's attempt to claim that he misrepresented research regarding the evolution of clotting proteins when he gave testimony in Kitzmiller v. Dover (way back in 2005).
See here and here. The third - and final - part will appear tomorrow apparently.
awild | January 3, 2009In the comments, Eric Eaton makes an observation:
Iâm left wondering (just a little) why Alex has such a beef with Dr. Wilson. This is not the first post taking a jab at Wilson, so while Alex makes an excellent point, Iâm also sensing some underlying issues hereâ¦.
Eric is right there's an issue. It is one many myrmecologists, especially systematists, have been tip-toeing around for a while now.
The short version is that Wilson is no longer at the leading edge of myrmecology. As he has fallen out of step with the practicing research community, his public ant commentary is increasingly at…
pharyngula | January 3, 2009This week, Nature magazine published a short list of recent important developments in evolutionary biology that support the theory of evolution, as a tool to help explain that evolution is definitely a dynamic and useful theory in our field and to demonstrate that the evidence is still growing. Here's a short summary of the 15 stories the editors picked out, but you should also read the freely available article, 15 Evolutionary Gems. Teachers, put this in your classroom!
The discovery of Indohyus, an ancestor to whales.
The discovery of Tiktaalik, an ancestor to tetrapods.
The origin of…
evolvingthoughts | January 2, 2009I's an ego thing, sure, but it's also a handy way of seeing what one did this past year. Here are what I think of as the substantial posts of Evolving Thoughts from 2008. Sorry for the lateness - it's a longish list. I (and my guest blogger) have been real busy this year...
Religion and Creationism
Desecration, blasphemy in public, and manners
Why are there still monkeys?
Can a Christian accept natural selection as true?
Does religion evolve?
The heat of religion
The religious we have always with us
Agriculture and the rise of religion
The origins of agriculture now extended
Darwin, God and…
clock | December 30, 2008Three Obligatory Readings of the Day:
Brian Switek: Stephen Jay Gould's view of life
Larry Moran: An Adaptationist View of Stephen Jay Gould
Greg Laden: How fast does evolution happen?
gregladen | December 30, 2008... and other matters.
The following list represents widely held beliefs, either first order beliefs (things you hear people say) or second order beliefs (things implied directly by what people say):
Evolution is very slow.
It takes millions of years for a species to evolve into another species.
Evolution has stopped for humans.
Evolution occurs over "geological time scales."
Geological time scales are very long ... millions of years.
Geological and evolutionary time scales are similar to each other.
Evolution = Natural Selection.
"Macro evolution" is slow, "Micro evolution" is fast but…
oracknows | December 30, 2008Here's one for our favorite creationist neurosurgeon: A whole Grand Rounds all about the interface of and application to medicine of the theory of evolution.
edyong | December 30, 2008In the twilit waters of the deep ocean, beneath about 1000m of water, swims the brownsnout spookfish (Dolichopteryx longipes). Like many other deep-sea fish, the spookfish is adapted to make the most of what little light penetrates to these depths, but it does so with some of the strangest eyes in the animal kingdom.
For a start, each eye is split into two connected parts, so the animal looks like it actually has four. One half points upwards and gives the spookfish a view of the ocean above. The other points downwards into the abyss below and it's this half that makes the spookfish unique.…
oracknows | December 29, 2008Last week, I gave everybody's favorite creationist neurosurgeon, Dr. Michael Egnor, the gift everyone loves to read but not to receive: the gift of not-so-Respectful Insolence. Christmas or no Christmas, he did ask for it, and far be it from me, given my benevolent nature, not to respond to his plaintiff plea with a resounding "Affirmative!" Nor was I alone. Others joined in. But apparently not everyone thought Dr. Egnor deserving of such a group slapdown. Apparently there is at least one blogger out there who thought that Dr. Egnor needed a defender. Apparently there is at least one blogger…
razib | December 29, 2008Neanderthal Extinction by Competitive Exclusion:
Despite a long history of investigation, considerable debate revolves around whether Neanderthals became extinct because of climate change or competition with anatomically modern humans (AMH).
...
We apply a new methodology integrating archaeological and chronological data with high-resolution paleoclimatic simulations to define eco-cultural niches associated with Neanderthal and AMH adaptive systems during alternating cold and mild phases of Marine Isotope Stage 3. Our results indicate that Neanderthals and AMH exploited similar niches, and…
laelaps | December 28, 2008I have to admit that one of my favorite targets of criticism is the "Dinosauroid," which I have previously mentioned on this blog multiple times (with the more detailed treatments here, here, and here). Even though paleontologist Dale Russell and taxidermist Ron Sequin stated that their hypothetical being might bear a little orthogenic bias, it was nonetheless presented a plausible hypothesis of what dinosaurs might have become had they not gone extinct. (Mind you, this predated the consensus that some dinosaurs still exist today; we just call them birds).
Perhaps, but the creature is so…
awild | December 28, 2008This morning I was picking through recent ant literature for a 2008 myrmecological retrospective post when I stumbled on this little gem.
Why do autumn leaves change to such striking colors? Kazuo Yamazaki thinks it's all about the ants:
Therefore, bright autumn leaves may have adaptive significance, attracting myrmecophilous specialist aphids and their attending ants and, thus, reducing herbivory and competition among aphids.
I hereby proclaim Kazuo Yamazaki the first recipient of an award in his own name, the Yamazaki "Going Way Out On A Limb" Award, for creative lateral thinking in…
edyong | December 28, 2008Solar power is a relatively new development for humans but, of course, many living things have been exploiting the power of the sun for millions of years, through the process of photosynthesis. This ability is usually limited to plants, algae and bacteria, but one unique animal can do it too - the emerald green sea slug Elysia chlorotica. This remarkable creature steals the genes and photosynthetic factories of a type of algae that it eats (Vaucheria littorea), so that it can independently draw energy from the sun. Through genetic thievery, it has become a solar-powered animal and a…
amillikan | December 27, 2008Scientists have long been torn about the exact evolution of birds since fossil and molecular dating techniques have yielded different answers. But by studying the DNA of birds in the parrot and cockatoo families, which do not migrate like most other birds, researchers were able to discern the times of species divergence and concluded that "parrots are an ancient lineage without any close evolutionary relationships," according to ScienceBlogger Grrl Scientist.
evolvingthoughts | December 26, 2008It is often said that one of the most significant discoveries in mathematics was the concept of zero, in the Indus valley sometime in the pre-Christian era. An equally important concept in logic is the operator NOT. While Aristotle, the founder of western logic, had discussed groupings of things in terms of what they are not in the Categories, chapter 10, the importance of NOT seems to have been realised first by George Boole in the nineteenth century. In this post I want to discuss it in the context of classification.
Aristotle wrote of four kinds of "contrarieties":
We must next explain the…
oracknows | December 26, 2008...more not-so-Respectful Insolence, courtesy not of Orac this time but of other skeptical physician-bloggers!
Enjoy:
Smackdown, please (yes, Egnor, I'm talking to you) (by blog bud PalMD)
Defending science-based medicine (by skeptical neurologist Dr. Steve Novella, who's been known to spar a bit with Dr. Egnor himself over evolution and neuroscience)
Egnorance is Bliss (by Dr. Kimball Atwood IV)