Recently in Evolution Category
Introgression or genetic exchange between crops and their wild relatives is of broad interest due to concern regarding the escape of transgenes from genetically engineered crops. Many fear the potential deleterious effects of such introgression including decreased fitness or diversity of wild relatives and/or the creation of “superweeds” that are resistant to the current arsenal of herbicides. But there is another side to crop-wild gene exchange. A paper published in the open-access journal PLoS Genetics this week reveals that crop-wild introgression is likely a longstanding and potentially beneficial phenomenon in some agroecosystems. Matthew Hufford, Jeffrey Ross-Ibarra and colleagues describe how introgression from wild relatives has shaped the genome of corn, potentially providing essential adaptations as it spread from a narrow center of domestication into novel environments.
Corn was domesticated in the lowlands of southwest Mexico ~10,000 years ago from a wild grass known as teosinte. A few thousand years later corn colonized the high altitudes of the Mexican Central Plateau. There, it came into contact with a different wild teosinte, one presumably well adapted to the new environment. Both corn and teosinte in the highlands have characteristics such as purple pigmentation and hairy stalks and leaves that are believed to help these plants tolerate the lower temperatures and higher ultra-violet radiation of the highlands. For some time, biologists have been stumped as to whether corn and teosinte obtained these highland adaptations independently or through introgression, with some arguing that the shared characteristics were a good example of maize genes escaping into the wild.
Photograph by Paul Ruggeri.
Photography contest, Honorable Mention.
Loxodonta africana – African elephant. Mud dries on the back of the elephant. The mud in the furrows between the folds remains moist, helping the elephant to keep cool in the heat. The dried mud on the folds helps protect against sunburn.
Casey Luskin is such a great gift to the scientific community. The public spokesman for the Discovery Institute has a law degree and a Masters degree (in Science! Earth Science, that is) and thinks he is qualified to analyze papers in genetics and molecular biology, fields in which he hasn't the slightest smattering of background, and he keeps falling flat on his face. It's hilarious! The Discovery Institute is so hard up for competent talent, though, that they keep letting him make a spectacle of his ignorance.
I really, really hope Luskin lives a long time and keeps his job as a frontman for Intelligent Design creationism. He just makes me so happy.
His latest tirade is inspired by the New York Times, which ran an article on highlights from the coelacanth genome. Luskin doesn't think very deeply, so he keeps making these arguments that he thinks are terribly damaging to evolution because he doesn't comprehend the significance of what he's saying. For instance, he sneers at the fact that we keep finding conserved elements in the genome, because as we all know, there are lots of conserved elements.
Narcissus sp. – daffodil. Slightly off task, but this daffodil was one of many passed out at a ceremony during which the Polish government awarded my friend Walter Plywaski, a Holocaust survivor, the Knight’s Cross of Merit, “in recognition of outstanding services to the Polish-American community in disseminating historical awareness on Polish and Jewish fates in the occupied Poland.” The 6 sepals represent the star of David.
The coelacanth genome has been sequenced, which is good news all around…except that I found a few of the comments in the article announcing it disconcerting. They keep calling it a "living fossil" — and you know what I think of that term — and they keep referring to it as evolving slowly
The slowly evolving coelacanth
The morphological resemblance of the modern coelacanth to its fossil ancestors has resulted in it being nicknamed 'the living fossil'. This invites the question of whether the genome of the coelacanth is as slowly evolving as its outward appearance suggests. Earlier work showed that a few gene families, such as Hox and protocadherins, have comparatively slower protein-coding evolution in coelacanth than in other vertebrate lineages.
Honestly, that's just weird. How can you say its outward appearance suggests it is slowly evolving? The two modern species are remnants of a diverse group — it looks different than forms found in the fossil record.
As we reflect upon the amazing body of work left behind by this giant of the movie scene, readers of the Thumb should know (if they don’t already) that Roger Ebert was a passionate defender of science, and of evolution in particular.
His passion was not un-noticed by creationists (of both young-earth and intelligent design categories). William Dembski had this to say about Ebert in an Uncommon Descent blog from 2006:
Roger Ebert: Film Critic, Expert on Evolution, ID Basher, and Overall Supergenius .….. Or is Ebert just another clueless bonehead whose imagined expertise is in exact disproportion to his actual knowledge …
Here are some memorable comments by Ebert on creationism, evolution, and religion.
The more you know about evolution, or simple logic, the more you are likely to be appalled by the film. No one with an ability for critical thinking could watch more than three minutes without becoming aware of its tactics. It isn’t even subtle. Take its treatment of Dawkins, who throughout his interviews with Stein is honest, plain-spoken, and courteous. As Stein goes to interview him for the last time, we see a makeup artist carefully patting on rouge and dusting Dawkins’ face. After he is prepared and composed, after the shine has been taken off his nose, here comes plain, down-to-earth, workaday Ben Stein. So we get the vain Dawkins with his effete makeup, talking to the ordinary Joe.
I have done television interviews for more than 40 years. I have been on both ends of the questions. I have news for you. Everyone is made up before going on television. If they are not, they will look like death warmed over. There is not a person reading this right now who should go on camera without some kind of makeup. Even the obligatory “shocked neighbors” standing in their front yards after a murder usually have some powder brushed on by the camera person. Was Ben Stein wearing makeup? Of course he was. Did he whisper to his camera crew to roll while Dawkins was being made up? Of course he did. Otherwise, no camera operator on earth would have taped that. That incident dramatizes his approach throughout the film. If you want to study Gotcha! moments, start here.
During in all the endless discussions on several threads of this blog about evolution, intelligent design, God and the afterworld, now numbering altogether around 3,500 comments, I have never said, although readers have freely informed me I am an atheist, an agnostic, or at the very least a secular humanist–which I am. If I were to say I don’t believe God exists, that wouldn’t mean I believe God doesn’t exist. Nor does it mean I don’t know, which implies that I could know.
Let me rule out at once any God who has personally spoken to anyone or issued instructions to men. That some men believe they have been spoken to by God, I am certain. I do not believe Moses came down from the mountain with any tablets he did not go up with. I believe mankind in general evidently has a need to believe in higher powers and an existence not limited to the physical duration of the body. But these needs are hopes, and believing them doesn’t make them true. … No, I am not a Buddhist. I am not a believer, not an atheist, not an agnostic. I am still awake at night, asking how? I am more content with the question than I would be with an answer.
The True Believers. Found in both parties. One side declares God without any doubt does exist, and created the universe and everything in it. A much smaller subset of this group is convinced that God did this in fairly recent times–as little as 6,000 years ago, or in any event too recently for Darwin’s evolutionary process to have had enough time to take place. The other side declares that God without any doubt does not exist, and it is equally certain. Both sides frequently quote the Bible, on the one hand citing its truth, on the other side citing its falsity. Christianity is the only religion involved; my blog has readers from all over the world, but apparently those from elsewhere find Intelligent Design a uniquely American notion.
The zealots of Creationism are indefatigable. Even now there are attempts to legislate that the pseudo science of Intelligent Design must be taught in school systems as a “debate” with Evolution. In common sense terms, that debate was over a century ago. Yet there are votes out there for politicians who support such legislation, and at the 2008 GOP presidential debate, no less that three candidates said they do not believe in evolution. I suppose I should be gratified that there weren’t more.
My only purpose today is to state early and often that if a Presidential candidate believes early humans used saddles to ride on the backs of dinosaurs, as they are depicted at the Creation Museum in Petersburg, Kentucky, that candidate should not be elected President.
And if a candidate counts among close friends and advisors anyone in communication with the spirit world, that candidate should not be elected President.
And if a candidate accounts for the fact that humanoid and dinosaur bones are never found at the same level in the fossil record by evoking the action of sediment after the Great Flood, that candidate should not be President.
And if a candidate has a spirit guide, consults his or her Chart and takes more than a passing amusement in the horoscope, that candidate should not be elected President.
There’s a category page linking these and other blogs, appropriately titled “Darwin My Hero”.
Comments about Roger Ebert are welcome. Comments that are nonsequiters, religious rants, or are otherwise irrelevant, will be tossed onto the Bathroom Wall.
Photograph by Jon Woolf.
Photography contest, Honorable Mention.
The Great Unconformity in the Grand Canyon. Mr. Wolf writes that the unconformity “demonstrates geologic time and a number of basic geologic rules that help to destroy YEC.”
After the unit on Creationism and Intelligent Design in my Critical Thinking/Science and Pseudoscience class at New Mexico Tech (Psych 189), I asked the students to write an essay on the question
Is “Intelligent Design” just another version of Creationism? Why?
Along came student Elaine, who included this comment in her essay:
It seems that if you are only comparing Intelligent Design against Creationism, there are enough subtleties to identify one or the other. However, if it is a case of arguing Intelligent Design vs. Creationism vs. evolution, the contrast between evolution and the other two is so great that Intelligent Design and Creationism become indistinguishable in their respective arguments. The only giveaway would be a reference to Genesis, the use of “God” rather than “Creator/Designer”, or some explicit differentiation between the two. In contrast, no one could ever possibly confuse an evolution argument with any other.
I remarked that the student had used evolution as an outgroup to correctly root the evolution/creationism/ID tree, and gave her an “A” for the assignment.
Photograph by Danny Satterfield.
Photography contest, Honorable Mention.
Banded gneiss on east coast of Greenland, south of Qaanaaq.
Photograph by Greg Mead.
Photography contest, Honorable Mention.
Mr. Mead writes, “It beautifully exhibits tilted and horizontal sedimentary layers, faults, and an erosional surface (an “unconformity”), all of which you can use to determine the relative age of the features. Even in this picture, the sediments include at least 20 easily identifiable beds, some separated by erosion, and they have been tilted below the unconformity.
“It is pretty much impossible for those to be formed by a single catastrophic event, and it is the kind of thing that caused naturalists, starting in the 17th century, to begin to understand the great age of the Earth.”
Photograph by James Wood.
Photography contest, Honorable Mention.
Tasmanipatus barretti – giant velvet worm found in a rotting log in northeast Tasmania. This species is restricted to a range of 600 km2 in the northeast corner of the state and is listed as rare under Tasmanian state legislation.
We have been going through our archives to find excellent contest entries that have not so far been posted. We begin with this picture, which dates from the first photography contest in 2009. Our apologies to the photographers, but we had an embarrassment of riches the first few years.
“Project Steve” is a tongue-in-cheek parody of a long-standing creationist tradition of amassing lists of “scientists who doubt evolution” or “scientists who dissent from Darwinism.”
Conceived in discussions amongst NCSE staffers and members of the old TalkDesign group (several of whom went on to be founding contributors to Panda’s Thumb), the Steve-O-Meter currrently shows 1,239 scientists whose first name is Steve or a cognate, including the two eligible living Nobel winners (Chu and Weinberg), who have signed on to this statement:
Evolution is a vital, well-supported, unifying principle of the biological sciences, and the scientific evidence is overwhelmingly in favor of the idea that all living things share a common ancestry. Although there are legitimate debates about the patterns and processes of evolution, there is no serious scientific doubt that evolution occurred or that natural selection is a major mechanism in its occurrence. It is scientifically inappropriate and pedagogically irresponsible for creationist pseudoscience, including but not limited to “intelligent design,” to be introduced into the science curricula of our nation’s public schools.
Since “Steve” and cognates comprise roughly 1% of first names, that corresponds to over 120,000 scientists concurring with the statement.
Compare that to the wishy-washy Scientific Dissent from Darwinism statement maintained by the Disco ‘Tute:
We are skeptical of claims for the ability of random mutation and natural selection to account for the complexity of life. Careful examination of the evidence for Darwinian theory should be encouraged.
Cell Reports, an open access journal of cell biology, has a special Darwin Day issue:
In celebration of Darwin Day 2013, we offer this collection of papers published in Cell Reports on various aspects of evolutionary biology. Topics range from experimental evolution in real time to explorations of the origins of signaling pathways in existence for nearly a billion years. Like all papers in Cell Reports, these articles are open access, free to read and distribute. We hope you enjoy the collection, which is perhaps best prefaced by Mr. Darwin himself:
It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, being Growth with Reproduction; Inheritance which is almost implied by reproduction; Variability from the indirect and direct action of the external conditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less-improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.
- On the Origin of Species, first edition, closing paragraph