evolution
evolvingthoughts | June 5, 2007
The Fall. What can we say about the Fall that hasn't been said many times before? Well, if all you read is the text, quite a lot.
The Serpent is interesting, for a start. He talks, and so he's a magical creature. He has a human-like personality, for he is "crafty" (although I really prefer the old term "subtle", for it makes him sound like a lawyer). He talks about YHWH Elohim only as "Elohim", for a start - I don't know what meaning there is in that. It's not that the Tetragrammaton (YHWH) had become sacred, for it is spread through Genesis and you'd expect it to be elided by the Redactor…
mikethemadbiologist | June 5, 2007Well, they're not giant, but, by way of Majikthise, I found this story about an isolated population of freshwater crabs that has been dwelling in Roman ruins for 3,000 years.
During this period of isolation, the crabs have increased in size by at least fifty percent and possibly more than 100% (based on molts) compared to the wild Greek popoulations. What's interesting is that the population is thought to be around 1,000 individuals, so there are some neat studies that can be done looking at the effects of genetic bottlenecks (we need a crab genome!). One thing puzzled me though:
While in…
evolvingthoughts | June 5, 2007
It is also likely that if God re-issued Genesis 2, he'd do it as a comic strip like this.
Oops I forgot to link it... fixed now.
evolvingthoughts | June 4, 2007
This three-part series is a talk I gave a while back to some ecologists and molecular biologists. It is a brief overview of the aims and relationship between science and philosophy of science, with a special reference to the classification wars in systematics, and the interface of science and the broader community. I will present my own overview of the elements of science - as a dynamic evolving entity of knowledge gathering rather than as a timeless methodology or as a purely social movement.
[Part 2, Part 3]
It isn't often that an ornithologist gets to talk to birds. It's even less…
purepedantry | June 4, 2007Thorpe and colleagues, publishing in the journal Science, have performed a study of orangutan movement that is turning the traditional view of the evolution of walking on its head.
The traditional view is that walking upright on the ground -- terrestrial bipedalism -- was preceded by a phase of knuckle walking on the ground. It was speculated that this phase would closely resemble how we see modern gorillas walking on the ground today.
However, Thorpe and colleagues, by observing orangutans moving through trees, are arguing that there was another way that terrestrial bipedalism could have…
pharyngula | June 3, 2007One of the common principles used to characterize the rules of growth in developing systems is the idea of allometry. Here, I'll briefly summarize the concept with a few clear illustrations and a tiny amount of simple math.
"Allometry" means "different growth or measurement", and it refers to the fact that different body parts grow at different rates during development—we aren't simply linearly scaled up versions of our younger selves, but instead we have different proportions. One vivid and familiar example is the growth of our heads. Look at a baby, and their heads and eyes seem huge…
pharyngula | June 2, 2007I can't help it—everything I read only makes sense in the light of evolution. Here, for instance, is a story about the popularity of the AK-47 assault rifle:
The AK-47's popularity is generally attributed to its functional characteristics; ease of operation, robustness to mistreatment and negligible failure rate. The weapon's weaknesses -- it is considerably less accurate, less safe for users, and has a smaller range than equivalently calibrated weapons -- are usually overlooked, or considered to be less important than the benefits of its simplicity. But other assault rifles are approximately…
clock | June 2, 2007Evolution of direct development in echinoderms
It's been several years since I last heard Rudolf Raff talk about his work and apparently he's been busy in the meantime. The new stuff is exciting, and PZ knows how to explain it really well.
pharyngula | June 2, 2007In chapter 14 of the Origin of Species, Darwin wondered about the whole process of metamorphosis. Some species undergo radical transformations from embryo to adult, passing through larval stages that are very different from the adult, while others proceed directly to the adult form. This process of metamorphosis is of great interest to both developmental and evolutionary biologists, because what we see are major transitions in form not over long periods of time, but within a single generation.
We are so much accustomed to see a difference in structure between
the embryo and the adult, that we…
oracknows | June 2, 2007Infophilia finds Dr. Michael Egnor's invocation of the Stalin Zombie from a couple of months ago and tears it apart.
Come to think of it, Egnor's been laying down some silliness about evolution lately. I had been restraining myself from commenting due to my previous oversaturation blogging about his antics, but I think I've given the blog a suitably long Egnor-free interval that it might be time to have some dismayed fun with our creationist neurosurgeon again...
evolvingthoughts | June 1, 2007
So in chapter 2, we shift stories. Now we have a story that is far older than the first chapter, and is regarded by scholars as the "Yahwist" creation story, and it focuses primarily on humans. The story is far more familiar than the first chapter is (the first few sentences notwithstanding), so we can be pretty brief.
Here, the deity is referred to as "YHWH Elohim", and is translated in English as "LORD God". YHWH is the ancient name for a Phoenician deity of the inhabitants of Canaan. We don't know exactly how it was pronounced, but problably it is said as "Yahweh". In the Canaanite…
voltagegate | June 1, 2007Photo: mindrec
We established that the giant and red panda co-inhabit the same habitat, but exploit very specific parts of that main habitat, different microhabitats. Giants stick to the low lands, feeding in sparse forest, while the reds alight the long branches of rhododenrons, stripping leaves from branches.
They are said to have a sympatric relationship, meaning that both pandas became separate species (speciation) while existing in the same area. Allopatry is the opposite process; it describes speciation by environmental isolation.
When ecologists and evolutionary biologists make…
mikethemadbiologist | June 1, 2007And in other news, dog bites man. Would the NY Times have printed an op-ed allowing a flat-earther to explain why he believes the earth is flat? Because that's what they did when they ran Brownback's defense of intelligent design creationism. And there's nothing original in Brownback's op-ed either.
First, Brownback makes this declarative statement:
The heart of the issue is that we cannot drive a wedge between faith and reason. I believe wholeheartedly that there cannot be any contradiction between the two. The scientific method, based on reason, seeks to discover truths about the nature…
evolvingthoughts | May 31, 2007
We're in the third day, and Elohim has made dry land, but no sun or stars or moon. Still, he's keen to see something growing, so he tells the land to produce, by spontaneous generation as it was later known, "seed bearing plants and plants bearing fruit with their proper seed inside". Seed here is crucial - God creates things that reproduce themselves through some innate generative power, but at first they come out of the land. Augustine, in De Genesi ad litteram declared that God acted out of a secondary power here - he didn't create these plants directly, but indirectly, by putting a…
voltagegate | May 31, 2007Many would like to paint evolution by natural selection as a vicious idea, drawing upon our fears of purposelessness and elitism by highlighting the misleading phrase, "survival of the fittest."
It can be a scary idea when applied to our society; we don't want to think of the disabled and handicapped as unfit in their environment. It seems to be a cold view of the world, devoid of compassion.
I can understand the apprehension. Fortunately, evolution is a biological process, not a cultural/societal process, so when it is superimposed on societal structure, it does not exactly fit the bill.…
clock | May 30, 2007Is natural selection omnipotent or are there developmental constraints to what is possible and it is only from a limited range of possibilities that natural selection has to choose? The tension betwen two schools of thought (sometimes thought of in terms of pro-Gould and anti-Gould, as he has written much about developmental constraints and against vulgar adaptationism) is still alive and well. It is nice to see someone actually do an experimental test of the thesis:
Why Are There No Unicorns?:
Why are there no unicorns? Perhaps horses develop in a way that cannot be easily modified to…
grrlscientist | May 30, 2007tags: cheetahs, evolution
Researchers studied 47 litters of cheetah cubs over nine years. Nearly half contained cubs from multiple fathers.
Image: Sarah Durant [larger]
DNA technology has revealed that female cheetahs, Acinonyx jubatus, often produce litters that are comprised of cubs sired by multiple fathers. This research, recently published in the Proceedings of the Royal Society B, studied cheetahs found on that part of the Seregeti in the African nation, Tanzania.
"If the cubs are genetically more variable it may allow them to adapt and evolve to different circumstances," Dada…
voltagegate | May 30, 2007Until very recently, no direct ancestors of the red panda (Ailurus) were known. Most paleontologists link Ailurus with previous, raccoon-like (procyonoid) fossil animals - Cynarctis, Phlaocyon, Aletocyon - mainly by the similarities in their molars.
A closer relative was described in the 1970's, an animal 50% larger than Ailurus found in Europe and North America, appropriately named Parailurus anglicus. Researchers concluded from these fossils that the red panda's ancestry was based solely in North America:
Intermediate forms between Parailurus and Ailurus are not known. The smaller size…
evolvingthoughts | May 29, 2007
A while back, I wrote a series of posts (listed at the end) on whether or not creationists were in fact being rational in their choices of who to believe about science, based on what information they had available to them as they were growing up.
Now, a paper has been published in The Edge by psychologists Paul Bloom and Deena Skolnick Weisberg, which is a revised version of a paper in Science, May 18, 2007, which argues pretty much the same thing. I only wish the paper I have forthcoming in Synthese had got published earlier, but they have data, something philosophers must avoid according…
evolvingthoughts | May 29, 2007
Denver Post is reporting that the US Army wants to use a major fossil site for bombing practice. The Picket Wire Canyonlands, in the Commanche National Grasslands, is included in a series of maps the Army has drawn up for increasing its ordinance ranges.
The landscape of southeast Colorado also crawls with history, but time may be running out on public access to the past as Fort Carson considers acquiring the land for war training.
This secluded valley is home to one of North America's richest dinosaurs finds - more than 1,300 individual tracks; 35 sites have yielded bones.
"The great…