The evolution of a sensitive lesson

Educators find ways of handling The Theory. Some skip it. Others hunt for a balance point.

By RON MATUS and DONNA WINCHESTER, Times Staff Writers
Published February 3, 2008

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Inverness Middle School science teacher Steve Crandall says he chooses to tell students that science doesn't have all the answers.
	[Ron Thompson | Times]

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Sometimes, Allyn Sue Baylor doesn't teach evolution in her science class, even though the state requires it. She knows of other teachers who duck the issue, too.

They fear a backlash.

"There are cases when parents have gotten really upset," said Baylor, who teaches at Palm Harbor Middle School in Pinellas County. "It's scary. You can lose your job."

Meanwhile, David Campbell, a science teacher at Ridgeview High in Clay County, near Jacksonville, heads off conflict by telling students what may seem obvious: There's a big difference between science and faith.

"The student needs to know, 'I'm not asking you to believe this. I'm just asking you to understand it,'" said Campbell, a 14-year veteran.

Which teacher is more representative of what happens in Florida classrooms?

Nobody knows.

As an emotional debate continues to unfold over Florida's proposed new science standards -- standards that students will be tested on next year -- it's surprisingly unclear how often kids raise concerns about evolution, how teachers respond, and how many avoid the topic altogether.

To answer those questions, the St. Petersburg Times attempted to contact more than 50 science teachers in the Tampa Bay area and beyond. Most did not respond.

A science supervisor in one district suggested teachers may be gun-shy given recent headlines. A spokeswoman in another district told principals to instruct their teachers not to talk to a Times reporter.

Of the 17 teachers who did respond, most said the controversy burns with far more fury outside their classrooms than it does within. Their collective take: Students and parents don't raise concerns often. And when they do, teachers try to answer respectfully and sensitively, stressing the science without stomping on faith.

"It may not satisfy them," said Charles Lassiter, a biology teacher at Fort White High School near Gainesville. "But it makes them comfortable enough to get through the unit."

* * *

Can it be that easy?

Officials at the Department of Education, the Florida Association of Science Teachers, the Florida Coalition for Science Literacy and the Florida Citizens for Science said as far as they know, no one has surveyed Florida science teachers on their concerns about teaching evolution.

But a suite of surveys outside Florida offer a nagging counterpoint, suggesting that many teachers avoid the subject.

"In short, there are too many biology teachers who won't, or don't, or can't teach evolution properly," according to an editorial in the January edition of the American Biology Teacher.

Some may be glossing over the subject because of their faith. A 1999 survey of biology teachers in Oklahoma, for example, found that 12 percent wanted to omit evolution and teach creationism instead. A similar survey in Louisiana found that 29 percent of biology teachers believed creationism should be taught, while in South Dakota, it was 39 percent.

Others may fear being dragged into a battle over belief. In a 2005 survey by the National Science Teachers Association, 31 percent of respondents said they had felt pressured by students, parents, or administrators to include creationism, intelligent design or other faith-based alternatives to evolution in their curriculum. Thirty percent said they felt pressure to de-emphasize or omit evolution.

Some teachers say the numbers ring true in Florida, too.

There is a "large subset of teachers out there who flat don't teach it because they're afraid," said Campbell, the Clay County teacher, who also is a member of the committee that helped write the draft science standards.

Once, when he and another teacher were coordinating lesson plans, they got to the part on evolution and she said, "I'm going to skip that one," Campbell said. Baylor, the teacher at Palm Harbor Middle, said she knows of two teachers who have avoided evolution because they're unsure how parents will react.

They get away with it because "virtually no one complains when a teacher does not teach evolution," said Randy Moore, a University of Minnesota professor who has edited several science education journals. "There is not an outcry for, 'Teach us evolution.'"

Would the proposed standards, which include the word "evolution," make teaching the subject any easier?

On the one hand, some say, teachers would be less likely to avoid the subject because their students would be tested on it on the high-stakes Florida Comprehensive Assessment Test. The Department of Education also is expected to conduct training on the new standards once they're rolled out.

On the other hand, if more teachers teach more evolution, classroom conflicts might increase.

"Eventually, you'd see less (conflict)," said Jason Wiles, who manages the Evolution Education Research Center at McGill University in Montreal, "The more students understand about evolution, the less likely they are to reflexively reject the scientific evidence."

* * *

The freshman in Dan McFarland's Advanced Placement biology class at Durant High had a thoughtful question.

He had read about a rock formation where radiometric dating found the layers on top appeared to be older than the layers on the bottom. How could that be, he wanted to know? And didn't that put a dent in evolutionary theory?

McFarland, a 24-year veteran, knew the student was a young-earth creationist -- somebody who believes God created the Earth a few thousand years ago -- and hardly a lone wolf at Durant in Plant City.

So, McFarland did what he always does in these situations. He told the student he didn't know the answer. But he suggested there may be scientific explanations. Perhaps the type of dating mechanism used wasn't appropriate, or maybe the formation had been affected by a geologic event that resulted in layers being switched topsy-turvy.

The student wasn't buying it. But he appreciated how McFarland handled his questions.

"He explained everything to the very best of his ability, but he didn't convince me," said Dan Barousse, now a senior who plans to study mechanical engineering in college next year. "It's three years later and I'm still a young-earth creationist."

Convincing the student, though, wasn't McFarland's goal.

"I'm not trying to disavow anyone of their religious beliefs," he said. "I'm trying to offer scientific explanations for natural phenomena. That's my job."

Many of the science teachers interviewed by the Times echoed that sentiment.

In 20 years of teaching science, Rena White, a teacher at Challenger Middle School in Cape Coral, said she has never dealt with a parent upset about evolution. (But frog dissection? That's a different story.) She tells them that their beliefs and values are important, and that they should hold on to them.

But if she asks them how old the Earth is on a test, she says, "the answer is 4.65-billion years."

* * *

It's unclear how often science teachers veer into the realm of faith, even if it's simply to make clear faith's distinction from science.

Nothing in the state science standards, either in the current version or in the proposed draft, bars teachers from doing that. But nothing explicitly tells them they can, either.

If students raise the issue, some teachers shield themselves by saying the state requires them to teach evolution. Others just say they don't have the expertise to answer. "I tell them I'm not equipped to answer their questions about creationism because I'm not a theologian," said Clifford Wagner, a 29-year veteran at Springstead High School in Hernando County.

So, some teachers don't go there. But some do. And given the importance of faith to some of their students, they say it's necessary to do so.

Some students "say they don't believe in evolution, they don't believe people came from monkeys," said Steve Crandall, an eighth-grade science teacher at Inverness Middle School in Citrus County and president of the Florida Association of Science Teachers. "You see their eyes perk up and you sense that it's an important question (to them). They deserve to be heard."

So, Crandall said, he listens. And then he tells his students this: There are some questions science can't answer.

"To me, there's room for the question of who created the universe and why," Crandall said. "But that's separate from how."

Times staff writer Tom Marshall contributed to this report. Ron Matus can be reached at matus@sptimes.com or (727) 893-8873. Donna Winchester can be reached at winchester@sptimes.com or (727) 893-8413.

What educators are saying

• "Teachers teach what they're expected to teach and they teach to the standards that they're given. They also use the state adopted textbook. Our teachers use the state adopted materials and the state standards to present the science they are expected to present." Nancy Marsh, Hillsborough County science supervisor
• "I am one of the teachers who is willing to talk about evolution in the classroom. But I've been advised by other teachers, 'Don't touch that subject.' They say, 'I'm afraid the parents will be angry. I'm afraid of the feedback I'll get.'" Michael Simmons, a biology teacher at Osceola High School in Largo
• "Some of the kids will say, 'I heard that God directed evolution.' We talk about it. We definitely don't shy away from the idea of God having something to do with it. I want kids to explore. I never teach them one way or the other, or that they are mutually exclusive." Allyn Sue Baylor, a seventh-grade science teacher at Palm Harbor Middle School
• "I've only had one student question evolution. He was pretty adamant that God made the world and that was the true story. I said, 'Well, some people believe that, but in science we don't deal with that. We deal with evidence and experiments and observations. That's what we're going to talk about in this class." Mary L. Watkins, a science teacher in Pinellas County Schools' hospital homebound program
• "I can honestly say that I have never had either a parent or a student who in any way objected to any sort of evolutionary ideas. There's nothing extreme being thrust upon them. It's a theory that is being taught. There are a lot of scientific principals behind the theory, and that's all that's being shared with them." Randy McGonegal, a biology teacher in the International Baccalaureate program at Palm Harbor University High School

Results from a teachers survey

A 2005 survey conducted by the National Science Teachers Association gauged how much pressure science teachers felt about evolution instruction in their classroom. Here are some results:

• 31 percent said they felt pressured to include creationism or Intelligent Design in their science classroom. Most of the pressure came from students (22 percent) and parents (20 percent).
• 30 percent said they felt pressured to de-emphasize or omit evolution or evolution-related topics from their curriculum.
• 85 percent said they felt well-prepared to explain the reasons why it's important for students to understand evolution; 11 percent said they did not.
• 19 percent said they de-emphasize or omit the term "evolution" in their lessons so as not to draw attention to it.

Definitions

• Darwin's theory of evolution: Says species have changed over millions of years, driven by their ability to adapt and survive in changing environments.
• Creationism: The belief that a god or gods created the Earth, the universe and life.
• Intelligent design: The belief that some systems found in nature, such as the human eyeball, are too complex to have formed without the intervention of an unnamed designer.

[Last modified February 2, 2008, 23:28:13]

Catholic News Agency

Austrian cardinal to present book on creation and evolution in San Francisco

Cardinal Christoph Schönborn

San Francisco, Jan 31, 2008 / 02:19 am (CNA).- Cardinal Christoph Schönborn, Archbishop of Vienna, will give an official presentation of his new book on creation and evolution in Berkeley, California this February.

Cardinal Schönborn’s book, titled “Chance or Purpose? Creation, Evolution, and a Rational Faith,” continues a long debate about God and the creation of the world. The cardinal’s book addresses the issues raised by recent atheist writers such as Richard Dawkins, Christopher Hitchens, Daniel Dennett, and Sam Harris.

The book also examines the interpretation of the Book of Genesis, the problem of evil and suffering in a world created by God and the place of humanity in relation to nature. The place of chance and divine purpose in human existence is another featured topic.

In 2006, the cardinal, who was the main editor of the official Catechism of the Catholic Church, published an opinion article on evolution in the New York Times. Some critics charged him with biblical literalism and Fundamentalist “creationism.” Both critics and proponents of the “Intelligent Design” movement tried to associate his name with that position.

Cardinal Schönborn distinguishes the biological theory of evolution from “evolutionism,” which he describes as the reduction of all reality to mindless, meaningless processes. Arguing that science and rationally grounded faith are not contradictory, the cardinal’s book examines philosophical and theological questions often overlooked or ignored by many contemporary thinkers.

The cardinal will speak at the Dominican School of Philosophy and Theology in Berkeley on February 15, from 2:15 - 3:45 pm Pacific Time. The book’s website is www.ChanceOrPurpose.com .

The Repeater

January 29, 2008, 6:52 pm

The Repeater

Olivia Judson

Here’s an evolutionist’s dream: 10,000 planet Earths, starting from the same point at the same time, and left to their own devices for four and a half billion years. What would happen? Could you go on safari from one planet to the next seeing an endless procession of wildly different organisms? Or would many of the planets be home to life forms that are broadly similar?

The conventional answer to this question — the one championed by the late Stephen Jay Gould, for example — is that chance events, from mutations to asteroids, play such a large role in evolution that each of the planets would be totally different. And probably, after four and a half billion years, they would be. I wish we could do the experiment, though. It might hold some surprises.

Looking around the Earth, it’s striking how often similar traits evolve in similar environments. So: birds living on remote islands typically lose the power of flight. Males in species (be they chimpanzees or yellow dung flies) where females are promiscuous tend to evolve high sperm counts and large testes. Animals that live in caves lose their eyes and their color: whether they live in Rwanda or Romania, they’re a pallid, blind lot, the troglodytes. Mammals that specialize on eating leaves — be they cows or langurs (that’s a monkey) — have evolved foreguts where bacteria break down the leaves, as well as special enzymes to help with digestion. Amazingly, the same phenomena are also seen in the hoatzin, a leaf-eating bird from South America. In short, evolution has a remarkable tendency to repeat itself.

That this happens has been known for decades. But now we’re unpicking the genetic basis for the repetitions. And the startling thing is, evolution often repeats itself at the genetic level, too.

Alizarin Red stained sticklebacks. Credit: Pamela Colosimo and David Kingsley, Stanford University.

As an example, take three-spine sticklebacks (Gasterosteus aculeatus). These little fish usually live in the ocean, but like salmon, they come into rivers to spawn. As the glaciers retreated at the end of the last ice age — a process that went on between ten and twenty thousand years ago — a series of lakes began to form in the northern hemisphere, and the sticklebacks moved into them. Initially, the lakes would have been linked to the oceans by streams and rivers, but as the glaciers retreated, the land rose up (ice is heavy), and the exits to the lakes closed, leaving the sticklebacks in each lake marooned and isolated. And so the animals stuck there began evolving to live exclusively in freshwater.

Which is a real-life version of the evolutionist’s dream: each lake is an evolutionary experiment, a natural laboratory. Because there are so many lakes, the experiment has been repeated many times; and because we know the ages of the lakes, we know roughly how long each experiment has been going on. And sure enough, fish in different lakes have evolved a variety of similar features, repeatedly and independently.

Drawing of marine sticklebacks. Credit: David Kingsley, Stanford University (based on Cuvier & Valenciennes, 1829).

Marine sticklebacks, for example, boast body armor: from head to tail, they are covered in rows of bony plates. Many freshwater sticklebacks have lost these. In marine sticklebacks, the pelvis is a complicated affair that comes complete with a pair of long spines. In some freshwater populations, individuals have a much reduced, lopsided pelvic structure. In others, they have just a remnant, a small, lopsided bone: the ghost of pelvis past.

Drawing of freshwater sticklebacks. Credit: David Kingsley, Stanford University (based on Cuvier & Valenciennes, 1829).

Mutations to a gene called Ectodysplasin have been implicated as the major culprit in loss of armor; another gene, Pitx1, has been fingered as the main agent of pelvis reduction. Yet the means by which the two genes have effected their changes are different.

Take Ectodysplasin first. In this case, a rare version of the gene exists at a low frequency in marine sticklebacks. Two copies of the rare version (you inherit one from each of your parents), and you have no plates. Two copies of the regular version, and you have all the plates. But if you have one of each, the sort of armor you have can vary. Some individuals will have all their plates. Others will have a sort of half-armor.

What seems to have happened is that when sticklebacks invaded each lake, some of the invaders carried this rare version with them. In the ocean, being without body armor is deadly: it makes you vulnerable to predators. But lakes don’t have the same dangers as the ocean — and armor is heavy and makes you less agile. Thus, in these new environments, being without body armor conferred a significant advantage, and so in lake after lake, the rare variant of the gene swept through the population.

Let’s turn now to the ghostly pelvis. Pelvic loss is much less common than armor loss. But if you find sticklebacks that lack a pelvis, you can bet that they came from large, shallow lakes where the water is soft, there are no large fish that might act as predators, and the vegetation is dense. Soft water has little calcium, and you need calcium to make the pelvic spines. Shallow lakes that are thick with weeds are home to predators like dragonflies, which enjoy having a stickleback for breakfast. And whereas the spines are a defense against being eaten by other fish — trout, say, or pike — and can actually induce the predator to spit out the stickleback instead of trying to swallow it, insect predators catch sticklebacks by grabbing the spines.

The difference between having a spiky pelvis or not is influenced by the expression of several genes, but as I said earlier, the main agent seems to be a gene called Pitx1. In sticklebacks with a proper pelvis, this gene is turned on at several different places in the developing fish, including the head, the pituitary and the spots on the side of the body where the pelvis should form. In those without, Pitx1 is switched on everywhere except the pelvic region, and the pelvis doesn’t grow.

There are a couple of interesting things about this discovery. The first is that the molecular basis of the change from pelvis to no pelvis does not involve a mutation to the protein-coding region of the Pitx1 gene itself. In other words, the protein made from the gene hasn’t changed. What has changed is the way the gene is expressed. This is in contrast to the sorts of mutations one often reads about as being involved in evolution, which typically involve changes to the protein itself.

A second interesting feature of the stickleback pelvis is that — unlike the armor plates — the loss is probably due to mutations having occurred independently in the different populations. What’s more, changes to the use of Pitx1 are also implicated in pelvic loss in nine-spine sticklebacks (Pungitius pungitius) — yet nine-spine and three-spine sticklebacks have been going their own evolutionary ways for at least 10 million years. Mice that have been genetically engineered to lack Pitx1 have a suite of abnormalities, including crushed faces and abnormal pituitaries, that cause them to die young. Intriguingly, they also have a reduced pelvis and hind limbs, and as with the sticklebacks, the reduction is lopsided and shows a greater loss on the right than on the left.

Which makes you wonder. Manatees — those charming marine mammals that cavort in the Florida keys and the West Indies — have also lost their hind legs. All that’s left of their pelvis is a lopsided bone, smaller on the right than on the left. Could Pitx1 have been involved here, too? So far, no one knows for sure. But I’d put money on it.

The idea that the same gene could be involved in mediating evolution of the same trait in creatures as distantly related as mammals and fish is exciting. And — to give one last example — while the relation between Pitx1 and the manatee’s missing hind legs is speculative rather than proven, there is much stronger evidence that a gene called Kit ligand is involved in mediating the evolution of light skin color in both sticklebacks and people.

This gene is by no means the only one that affects human skin color; nonetheless, genetic differences in the regulatory regions of this gene have a significant effect on how light or dark your skin will be, or whether you have blond hair. In sticklebacks, meanwhile, pale skin often evolves in freshwater — perhaps as a disguise — and the change again maps to Kit ligand, and involves alterations in the way Kit ligand is expressed in particular tissues.

Here, I’ve focused on one particular version of the evolutionist’s dream. But there are many others. In northeastern Mexico, for instance, a small fish known as Astyanax has, on a number of occasions, taken up residence in caves: populations of the fish have been found in more than 25 caves, some of them hundreds of miles apart. This system, too, is giving us a glimpse of the genetics of repeated evolution.

And I haven’t even mentioned the hundreds of actual experiments — bacteria or yeasts evolving for generations in the laboratory. Yet all these systems show the same thing: at the genetic level, evolution is, to a remarkable extent, a repeater.

**********

NOTES:

Gould discussed the role of contingency in evolution in a number of books and articles, but see especially Gould, S. J. 2000. “Wonderful Life.” Vintage.

Examples of similar traits appearing in similar environments are numerous, and can be found in any textbook on evolution; but for details of the hoatzin, see Kornegay, J. R., Schilling, J. W., and Wilson, A. C.. 1994. “Molecular adaptation of a leaf-eating bird: stomach lysozyme of the hoatzin.” Molecular Biology and Evolution 11: 921-928.

For an excellent overview of evolution repeating itself at the genetic level, see Wood, T. E., Burke, J. M., and Rieseberg, L. H. 2005. “Parallel genotypic adaptation: when evolution repeats itself.” Genetica 123: 157-170.

For the genetics of armor inheritance, see Colosimo, P. F., Peichel, C. L., Nereng, K., Blackman, B. K., Shapiro, M. D., Schluter, D., and Kingsley, D. M. 2004. “The genetic architecture of parallel armor plate reduction in threespine sticklebacks.” PloS Biology 2: 635-641. For selective sweeps on Ectodysplasin, see Colosimo, P. F., Hosemann, K. E., Balabhadra, S., Villareal Jr, G., Dickson, M., Grimwood, J., Schmutz, J., Myers, R. M., Schluter, D., Kingsley, D. M. 2005. “Widespread parallel evolution in sticklebacks by repeated fixation of Ectodysplasin alleles.” Science 307: 1928-1933.

The forces that lead to loss of the pelvis in sticklebacks were described to me by Dr David Kingsley, of Stanford University, in a telephone conversation. For the role of Pitx1 in pelvic loss, see Shapiro, M. D., Marks, M. E., Peichel, C. L., Blackman, B. K., Nereng, K. S., Jonsson, B., Schulter, D., and Kingsley, D. M. 2004. “Genetic and developmental basis of evolutionary pelvic reduction in threespine sticklebacks.” Nature 428: 717-723. For the comparison between three-spine and nine-spine sticklebacks and the manatee, see Shapiro, J. D., Bell, M. A., and Kingsley, D. M. 2006. “Parallel genetic origins of pelvic reduction in vertebrates.” Proceedings of the National Academy of Sciences 103: 13753-13758.

For the evolution of pigmentation in sticklebacks and humans, see Miller, C. T., Beleza, S., Pollen, A. A., Schluter, D., Kittles, R. A., Shriver, M. D., and Kingsley, D. M. 2007. “cis-Regulatory changes in Kit ligand expression and parallel evolution of pigmentation in sticklebacks and humans.” Cell 131: 1179-1189.

For more about the Mexican cave fish Astyanax, see Protas, M. E., Hersey, C., Kochanek, D., Zhou, Y., Wilkens, H., Jeffery, W. R., Zon, L. I., Borowsky, R., and Tabin, C. J. 2006. “Genetic analysis of cavefish reveals molecular convergence in the evolution of albinism.” Nature Genetics 38: 107-111.

Researchers identify brain's 'eureka' circuitry

Researchers have found the brain region that controls the decision to halt your midnight exploration of the refrigerator and commence enjoyment of that leftover chicken leg. What's more, they said, such mechanisms governing exploration are among those that malfunction in addiction and mental illness.

Emmanuel Procyk and colleagues published their findings in the January 24, 2008, issue of the journal Neuron, published by Cell Press.

In their experiments, the researchers presented monkeys with a choice of touch targets on a computer screen, requiring the monkeys to spend time exploring which target would trigger a juice reward. Once the monkeys discovered the reward target, the researchers then gave the animals a period during which they could repeatedly touch the reward target to obtain more juice.

During the trials, the researchers recorded the electrical activity of hundreds of neurons in the anterior cingulate cortex (ACC), a brain region known to be active in adaptive behaviors such as the shift between exploring and exploiting.

In their analysis, the researchers measured the electrophysiological activity of cells during four different types of feedback—incorrect choices, first reward, repetition of the reward, and the ending of a trial by breaking fixation on the targets.

Analyzing the results, the researchers concluded that "Our data show that ACC discriminates between different types of feedback, allowing appropriate behavioral adaptations."

They wrote that "Thus, the function we attribute to ACC activations is clearly not only to evaluate feedbacks but is also to participate in monitoring the different steps of the task at hand to optimize action adaptation and valuation. A dysfunction of these mechanisms represents the core feature of cognitive alterations observed in addiction and mental illness."

Wrote Procyk and colleagues, "The ACC produces signals that discriminate between various behaviorally relevant positive and negative feedbacks, suggesting a role in triggering appropriate adaptations. Our data reinforce the proposal that ACC is important for establishing action valuations. But they also emphasize a combined role in monitoring events/actions for behavioral regulation when task control is high, underlining the intimate link between control and action valuation."

Source: Cell Press

http://www.physorg.com/news120314812.html

Platypus Much Older Than Thought, Lived with Dinos

Scott Norris for National Geographic News

January 22, 2008

Australia's duck-billed platypus has been around much longer than previously thought, according to a new fossil study that found the egg-laying mammal's origin traces back to the dinosaur days. Platypuses and their closest evolutionary relatives, the four echidna species, were thought to have split from a common ancestor sometime in the past 17 million to 65 million years. But remains of what was believed to be a distant forebear of both the platypus and the echidna—the fossil species Teinolophos—actually belong to an early platypus, according to scientists who performed an x-ray analysis of a Teinolophos jawbone. The finding means the two animals must have separated sometime earlier than the age of the fossil—at least 112 million years ago. Outlived the Dinos The international team, led by Timothy Rowe, of the University of Texas in Austin, used a specially modified CT scanner to capture high-resolution images of the internal structure of a 112.5- to 122-million-year-old Teinolophos jawbone found in southeastern Australia. The scientists found that the Teinolophos had already developed features thought to be unique to modern platypuses, including an electro-sensitive "bill" for finding aquatic prey. "This pushes the platypus back across the K-T boundary," Rowe said, referring to the mass extinction event that wiped out the dinosaurs about 65 million years ago. "Now it looks like [platypuses] crossed the boundary without any problem." The study appears in today's edition of the journal Proceedings of the National Academy of Sciences. Unique Jawbones Platypus bills are complex sensory organs loaded with electrical receptors. In murky waters the animals hunt by tracking the weak electrical fields generated by muscle activity in fish and other prey. Teinolophos had an electro-sensitive bill, the scientists concluded after imaging revealed a broad canal running through the bone of the lower jaw. All mammals have some type of canal that conducts nerve fibers to the teeth, Rowe noted. But in the platypus, this canal is greatly enlarged to accommodate a massive network of fibers that carry sensory information from the bill. The claim that Teinolophos is a very ancient platypus rests largely on this feature. "Nothing but the platypus has this huge canal," Rowe said. But Matt Phillips, of the Australian National University in Canberra, said more evidence may be needed. The research "does not confirm that the platypuses and echidnas diverged more than 112 million years ago," Phillips said. Phillips offered an alternative explanation for the new findings—that an early platypus-echidna ancestor had wide jaw canals, and this feature was retained by platypuses but reduced during subsequent echidna evolution. In such a scenario, the split of the two species could still have been relatively recent, Phillips said. Lead author Rowe counters that evidence for a more recent divergence is weak. He says it makes more sense to assume the wide canals are a unique feature of the platypus lineage. Resetting the Molecular Clock Because platypus and echidna fossils are rare, Rowe noted, most previous estimates of the strange animals' antiquity were based on molecular rather than fossil evidence. The gradual accumulation of changes in the DNA of closely related species provides a kind of "molecular clock" that biologists can use to estimate when the species branched apart from one another. DNA changes, however, don't occur at the same rate in different kinds of animals. The clock must be calibrated using other evidence, such as fossils. Studies suggesting a more recent platypus origin have used a molecular clock calibrated with fossil information from marsupials and other mammals, not platypuses and echidnas, Rowe said. The newfound early days of the platypus suggest that molecular evolution in platypuses and echidnas has proceeded at a far slower pace than in other mammal groups, the researchers say. "None [of the molecular studies] predicted we'd find a platypus this old," Rowe said. "The picture now emerging is that the monotremes are 'slow' in many respects," he continued. Platypuses and echidnas are the only extant "monotremes," or mammals that lay eggs. "Their metabolic and respiration rates are slower, their body temperature is lower, and it's possible that the monotreme lineage evolved at really slow rates," he said.

CT scans of a fossil jawbone (pictured above) reveal a large jaw canal in a creature once thought to be a forebear of the platypus and related species.

Scientists say the large jaw suggests the fossil actually is from a type of platypus, a finding that sets the origin of the duck-billed, egg-laying mammal back tens of millions of years earlier than previously believed.

http://news.nationalgeographic.com/news/2008/01/080122-platypus.html

Scientific American News - January 24, 2008

Longest Piece of Synthetic DNA Yet

Scientists have created an entire bacterial genome with off-the-shelf chemicals

By Coco Ballantyne

LIFE FROM SCRATCH? Scientists concoct longest strand of synthetic DNA to date
iStockPhoto

Scientists today announced that they have crafted a bacterial genome from scratch, moving one step closer to creating entirely synthetic life forms--living cells designed and built by humans to carry out a diverse set of tasks ranging from manufacturing biofuels to sequestering carbon dioxide.

Researchers at the J. Craig Venter Institute (JCVI) in Rockville, Md., report in the online edition of Science that they pieced together the genes of Mycoplasma genitalium, the smallest free-living bacterium that can be grown in the laboratory and a common culprit in urinary tract infections.

"The 582,970 base pair M. genitalium bacterial genome is the largest chemically defined structure synthesized in the lab," lead author Daniel Gibson told ScientificAmerican.com via e-mail. (Base pairs are complementary linked nucleotide bases, such as adenine–thymine.)

"It's the first time a genome the size of a bacterium has chemically been synthesized that's about 20 times longer than [any DNA molecule] synthesized before," adds Christopher Voigt, an assistant professor of bioengineering at the University of California, San Francisco, who was not involved in the study.

The research team, led by Nobel laureate Hamilton Smith, ordered short strands of genetic code from commercial DNA synthesis companies in the U.S. and Germany and stitched them into longer and longer strands using standard molecular biology techniques. To assemble the largest pieces of DNA, they inserted them into yeast cells and exploited a natural process called "homologous recombination," which is used by yeast to repair damaged DNA. The experiment's final product is equivalent to the naturally occurring genetic code of M. genitalium, with two minor exceptions: The scientists disabled the gene that gave the bug power to infect human cells, and they added a few "watermarks," short strips of signature genetic code that identify the product as man-made.

"This completes the second step of a three-step process in creating a synthetic organism," Gibson says. The first step came last summer when JCVI scientists transformed one species of bacteria into another with a DNA transplant, switching the identity of one bug by impregnating it with another's genetic code. The second step, constructing a synthetic bacterial genome, has now been accomplished with this study. The final step will involve inserting the synthetic genome into a cell and bringing it to life; Gibson says experiments with this goal are currently underway.

"We want to emphasize that we have not yet booted up the synthetic chromosome," JCVI founder Craig Venter said in a conference call with journalists this morning. There are multiple steps that must be overcome, the biologist explained, but "we are confident that they can be overcome."

"The ultimate step is proving what they have synthesized is biologically active," says Eckard Wimmer, a molecular biologist at Stony Brook University in Long Island, N.Y., who led the effort to construct synthetic polio, the first synthetically built virus. "Unfortunately, this very critical point is missing here."

If the researchers succeed in creating their synthetic bacteria, they will be closer to conceiving artificial creatures that could be used to mitigate some of society's greatest problems, among them climate change and overdependence on fossil fuels. Venter's team belongs to a cadre of scientists practicing synthetic biology, a burgeoning discipline that aims to design and build living things from the raw materials of life (organic chemicals) and nature's blueprints (genetic codes). Synthetic biologists also draw up their own blueprints, designing genetic sequences that nature never fathomed; the idea is to create novel functions for living things. Man-made microbes that manufacture pharmaceuticals, crank out cheap biofuels, mop up pollutants and oil spills or invade and destroy cancer cells may be just a decade or two away.

Venter's group is trying to create a completely synthetic bare-bones version of M. genitalium with a genome stripped of all but the most vital genes. The goal is to use this organism as chassis into which new genes can be added--perhaps ones that would give the germ the ability to spin silk, detect toxins or manufacture drugs. The possibilities seem endless, albeit not all rosy.

Critics have pointed out that the same synthetic biology know-how and technologies could be used by terrorists or rogue states to engineer a bacterium that churns out a neurotoxin or, perhaps, a deadly flu virus with resistance to vaccines and antiviral medications. Leaders in the field recognize the potential for misuse, both accidental and intentional, and have begun to address the issue. In October, members of JCVI, the Center for Strategic & International Studies and the Massachusetts Institute of Technology released a report offering policy options for oversight, and several leading synthetic biologists have published papers on the matter in peer-reviewed journals.

Looking at potential applications, not everyone agrees on the best strategy for manufacturing these promising organisms. The sleekest bug is not necessarily the best, points out George Church, a geneticist at the Harvard Medical School in Cambridge, Mass., and director of the Lipper Center for Computational Genetics. "Simplicity is overrated. E. Coli, with all its so-called junk DNA, is way more efficient than Mycoplasma," he says, noting that E. Coli's genome is about eight times bigger but grows about 50 times faster.

A company called LS9, Inc., in San Carlos, Calif., has already taken advantage of E. coli’s productivity, engineering the bug to churn out DesignerBiofuels, "a family of fuels that has properties indistinguishable from those of gasoline, diesel, and jet fuel," according to the company's Web site. Instead of rebuilding E. Coli from scratch, LS9 has taken the organism from nature and modified it by inserting fragments of synthetic DNA, an approach that, Church notes, is much less costly and easy to scale up for industrial purposes.

Regardless of what approach yields the most return, synthetic biology is, no doubt, racing forward. In the last few years DNA synthesis techniques have become faster, cheaper and accessible to more people. Ordering DNA from commercial outfits has become as easy as ordering pizza, according to Voigt, who projects that in upcoming decades scientists will be able to whip up much larger segments of DNA: synthetic genomes for yeast, animals--perhaps even humans.

Wednesday, January 23, 2008 | Science : Teaching Science |

The real danger in Darwin is not evolution, but racism

by Tony Campolo, Bill Clinton's pastoral counsellor

Reposted from:
http://www.philly.com/inquirer/currents/13930496.html

Tony Campolo is professor emeritus of sociology at Eastern University and served as pastoral counselor to former President Clinton

Many who support the separation of church and state say that the intelligent design theory of creation ought not to be taught in public schools because it contains a religious bias. They dislike its suggestion that the evolutionary development of life was not the result of natural selection, as Charles Darwin suggested, but was somehow given purposeful direction and, by implication, was guided by God.

Arguing for what they believe is a nonprejudicial science, they contend that children in public schools should be taught Darwin's explanation of how the human race evolved, which they claim is value-free and depends solely on scientific evidence.

In terms of science, Darwin's account may be solid indeed. But value free? Nothing could be further from the truth - and that's where the problem lies.

Some creationists fear Darwin because his theories contradict their literal biblical belief that creation occurred in six 24-hour days. But they do not get at the real dangers of Darwinism. They do not realize that an explanation of the development of biological organisms over eons of time really does not pose the great threat to the dignity of our humanity that they suppose. Instead, they, along with the rest of us, should really fear the ethical implications of Darwin's original writings.

In reality, those writings express the prevalent racism of the 19th century and endorse an extreme laissez-faire political ideology that legitimizes the neglect of the suffering poor by the ruling elite.

Those who argue at school board meetings that Darwin should be taught in public schools seldom have taken the time to read him. If they knew the full title of On the Origin of Species by Means of Natural Selection, or the Preservation of Favored Races in the Struggle for Life, they might have gained some inkling of the racism propagated by this controversial theorist. Had they actually read Origin, they likely would be shocked to learn that among Darwin's scientifically based proposals was the elimination of "the negro and Australian peoples," which he considered savage races whose continued survival was hindering the progress of civilization.

In his next book, The Descent of Man (1871), Darwin ranked races in terms of what he believed was their nearness and likeness to gorillas. Then he went on to propose the extermination of races he "scientifically" defined as inferior. If this were not done, he claimed, those races, with much higher birthrates than "superior" races, would exhaust the resources needed for the survival of better people, eventually dragging down all civilization.

Darwin even argued that advanced societies should not waste time and money on caring for the mentally ill, or those with birth defects. To him, these unfit members of our species ought not to survive.

In case you think Darwin sounds like a Nazi, there is a connection. Darwin's ideas were complicit in the rise of Nazi ideas. Pulitzer Prize winner Marilynne Robinson, in her insightful essay on Darwin, points out that the German nationalist and anti-Semitic writer Heinrich von Treitschke and the biologist Ernst Haeckel also drew on Darwin's writings to justify racism, nationalism and harsh policies toward the poor and less privileged. Although these men's lives much predated Hitler's rise to power, their ideas were very influential as he developed the racist ideas that led to the Holocaust. Konrad Lorenz, a biologist who belonged to the Nazi Office for Race Policy and whose work supported Nazi theories of "racial hygiene," made Darwin's theories the basis for his reasoning.

I hope our schoolchildren will be taught that it is up to science to study the processes that gave birth to the human race. But, as postmodern as it may be, I also want them to learn that whatever science discovers about our biological origins, there is, nevertheless, a mystical quality in human beings that makes each of us sacred and of infinite worth.

Regardless of how we got here, we should recognize that there is an infinite qualitative difference between the most highly developed ape and each and every human being. Darwin never recognized this disjuncture. And that is why his theories are dangerous.

Tony Campolo is author of "Letters to a Young Evangelical."

Todd »

Creationism Corrupts Our Youth, Says Democratic Presidential Candidate Gravel

By Sarah Lai Stirland January 27, 2008 | 11:50:49 PMCategories: Election '08

While the rest of the raft of presidential candidates are busily proclaiming their firm belief in a Christian God, former Alaska senator Mike Gravel has recorded a delightfully frank denouncement of religion in politics.

The quirky Democratic presidential candidate says what's obvious to any student of history: That aligning specific religious views with politics is a dangerous exercise.

"I am deeply insulted that in some areas that not only is evolution is shunned but efforts are made to substitute it with creationism and all other kinds of teachings, which corrupt our youth," he says in a YouTube video recorded on Saturday. "There’s no foundation for this. I think it’s unfortunate. We’re regressing in these areas, and so I think we have responsibility to our children to provide them with the greatest scientific information available to all of us, and that begins with respect to evolution."

Gravel goes on to talk about morality, and how trying to legislate morality reflects a failure of the religious community.

Clearly pointing to former Arkansas governor Mike Huckabee, a Republican who recently suggested that we ought to amend the constitution to be brought in line with "God's standards," Gravel said: "I ... really exhort as public policy that we concentrate on keeping religion out of politics, and keeping a very, very strong separation between church and state. Otherwise you will take the oppressive nature of the state and marry it with the oppressive nature of religion, and that is the ultimate oppression of human beings."

Resolution:

Whereas science is defined as and limited to explanations based on natural, observable and testable phenomena and, therefore, is explicitly distinguished from other types of explanations that depend on concepts relating to the supernatural (for example,” intelligent design”, “creation science", and” informed debate” paradigms); and

Whereas, learning and inquiry are severely inhibited if teachers are placed in a position where they may feel pressured to alter their teaching of the fundamental concepts of science in response to demands external to scientific disciplines; and,

Whereas, evolution theory is fundamental to a thorough understanding of biological concepts as reflected in the Indiana teaching standards,

Therefore be it resolved that the Indiana Academy of Science, as a part of its commitment to educational excellence in science instruction, opposes any restriction or imposition on the teaching of biological and cosmic evolution in the curricula of Indiana's educational institutions.

Explanation:

Indiana scientists and educators recognize the critical importance of a strong grounding in the fundamental principles of science for all of Indiana's youths. The extensive reasoning and consideration that has gone into the official position of the Indiana Academy of Science on this issue (described in the resolution above) parallels that of all significant scientific and science education organizations across North America. If you are interested in more details on the justification for this important and unanimous stance across these institutions, we strongly recommend that you go to the WWW links provided below for the National Academy of Science, the American Association for the Advancement of Science, the National Science Teachers Association and the National Center for Science Education.

These organizations provide helpful background information on science, science education, and the distinction between scientific and supernatural explanations of life. The fact that this information is typically highlighted on the front pages of their web sites is an indication of the importance placed on this issue. The Indiana Academy of Science fully endorses the resolutions and policies of these prominent institutions in order to promote instruction in science unencumbered by non-scientific explanations of life and the cosmos.

http://nationalacademies.org/evolution/#statements

http://www.aaas.org/news/press_room/evolution/

http://pubs.nsta.org/galapagos/resources/page1.html

http://www.natcenscied.org/

Indiana Academy of Science adds its voice for evolution

The Indiana Academy of Science adopted a resolution (document) in 2007 supporting the teaching of evolution as critically important in "a strong grounding in the fundamental principles of science for all of Indiana's youths":

Whereas science is defined as and limited to explanations based on natural, observable and testable phenomena and, therefore, is explicitly distinguished from other types of explanations that depend on concepts relating to the supernatural (for example," intelligent design", "creation science", and" informed debate" paradigms); and
Whereas, learning and inquiry are severely inhibited if teachers are placed in a position where they may feel pressured to alter their teaching of the fundamental concepts of science in response to demands external to scientific disciplines; and,
Whereas, evolution theory is fundamental to a thorough understanding of biological concepts as reflected in the Indiana teaching standards,
Therefore be it resolved that the Indiana Academy of Science, as a part of its commitment to educational excellence in science instruction, opposes any restriction or imposition on the teaching of biological and cosmic evolution in the curricula of Indiana's educational institutions.

The Academy explains, "The extensive reasoning and consideration that has gone into the official position of the Indiana Academy of Science on this issue (described in the resolution above) parallels that of all significant scientific and science education organizations across North America."

Founded in 1885, the Indiana Academy of Science is a non-profit organization whose purpose is to promote scientific research and to encourage communication between Indiana scientists and others conducting research pertaining to Indiana. It boasts over 1200 members who "share an interest in the progress of science and science education and a desire that science and scientists play a major role in the growth of Indiana."

January 28, 2008

Life's Ingredients Detected In Far Off Galaxy

Two ingredients that build life-forming amino acids have been detected in the ultra-luminous starburst galaxy, Arp 220. (Credit: Chandra Observatory, NASA)

ScienceDaily (Jan. 15, 2008) — Astronomers from Arecibo Observatory radio telescope in Arecibo, Puerto Rico, have detected for the first time the molecules methanimine and hydrogen cyanide -- two ingredients that build life-forming amino acids -- in a galaxy some 250 million light years away.

When combined with water, the molecules form glycene, the simplest amino acid and a building block of life on Earth.

The Arecibo astronomers focused on the distant galaxy Arp 220, an ultra-luminous starburst galaxy, because it forms new stars at a very high rate. They used the 305-meter, or 1,000-foot diameter, Arecibo radio telescope, the world's largest and most sensitive, to observe the galaxy at different frequencies. The observations, made in April 2007, were the first use of the 800 megahertz wide-band mode of the telescope's main spectrometer.

The molecules were found by searching for radio emission at specific frequencies. Each chemical substance has its own unique radio frequency, much like people have unique fingerprints.

"We weren't targeting any particular molecule, so we didn't know what we were going to find -- we just started searching, and what we found was incredibly exciting," said Tapasi Ghosh, an Arecibo astronomer.

"The fact that we can observe these substances at such a vast distance means that there are huge amounts of them in Arp 220," said Emmanuel Momjian, a former Arecibo astronomer, now at the National Radio Astronomy Observatory in Socorro, N.M. "It is indeed very intriguing to find that the ingredients of life appear in large quantities where new stars and planets are born."

The astronomy team, led by Arecibo astronomer Christopher Salter, announced the discovery Jan. 11 in a poster presented at the American Astronomical Society meeting in Austin, Texas. In addition to Salter, Momjian and Ghosh, the other researchers included Arecibo astronomers Robert Minchin and Mikael Lerner; Barbara Catinella, a former Arecibo astronomer now at the Max Plank Institute for Astrophysics in Germany; and Mayra Lebron, a former Arecibo astronomer now at the University of Puerto Rico.

The Arecibo Observatory is part of the National Astronomy and Ionosphere Center, a national research center operated by Cornell for the National Science Foundation.

Adapted from materials provided by Cornell University.

Cornell University (2008, January 15). Life's Ingredients Detected In Far Off Galaxy. ScienceDaily. Retrieved January 16, 2008, from http://www.sciencedaily.com/releases/2008/01/080114110715.htm

Growing Scientific Evidence Supporting Evolution 12 Jan 2008 The National Academy of Sciences (NAS) and Institute of Medicine (IOM) have released SCIENCE, EVOLUTION, AND CREATIONISM, a book designed to give the public a comprehensive and up-to-date picture of the current scientific understanding of evolution and its importance in the science classroom. Recent advances in science and medicine, along with an abundance of observations and experiments over the past 150 years, have reinforced evolution's role as the central organizing principle of modern biology, said the committee that wrote the book. "SCIENCE, EVOLUTION, AND CREATIONISM provides the public with coherent explanations and concrete examples of the science of evolution," said NAS President Ralph Cicerone. "The study of evolution remains one of the most active, robust, and useful fields in science." "Understanding evolution is essential to identifying and treating disease," said Harvey Fineberg, president of IOM. "For example, the SARS virus evolved from an ancestor virus that was discovered by DNA sequencing. Learning about SARS' genetic similarities and mutations has helped scientists understand how the virus evolved. This kind of knowledge can help us anticipate and contain infections that emerge in the future." DNA sequencing and molecular biology have provided a wealth of information about evolutionary relationships among species. As existing infectious agents evolve into new and more dangerous forms, scientists track the changes so they can detect, treat, and vaccinate to prevent the spread of disease. Biological evolution refers to changes in the traits of populations of organisms, usually over multiple generations. One recent example highlighted in the book is the 2004 fossil discovery in Canada of fish with "intermediate" features -- four finlike legs -- that allowed the creature to pull itself through shallow water onto land. Scientists around the world cite this evidence as an important discovery in identifying the transition from ocean-dwelling creatures to land animals. By understanding and employing the principles of evolution, the discoverers of this fossil focused their search on layers of the Earth that are approximately 375 million years old and in a region that would have been much warmer during that period. Evolution not only best explains the biodiversity on Earth, it also helps scientists predict what they are likely to discover in the future. Over very long periods of time, the same processes that enable evolution to occur within species also can result in the appearance of new species. The formation of a new species generally takes place when one subgroup within a species mates for an extended period largely within that subgroup, often following geographical separation from other members of the species. If such reproductive isolation continues, members of the subgroup may no longer respond to courtship from members of the original population. Eventually, genetic changes become so substantial that members of different subgroups can no longer produce viable offspring. In this way, new species can continually "bud off" of existing species. Despite the overwhelming evidence supporting evolution, opponents have repeatedly tried to introduce nonscientific views into public school science classes through the teaching of various forms of creationism or intelligent design. In 2005, a federal judge in Dover, Pennsylvania, concluded that the teaching of intelligent design is unconstitutional because it is based on religious conviction, not science (Kitzmiller et al. v. Dover Area School District). NAS and IOM strongly maintain that only scientifically based explanations and evidence for the diversity of life should be included in public school science courses. "Teaching creationist ideas in science class confuses students about what constitutes science and what does not," the committee stated. "As SCIENCE, EVOLUTION, AND CREATIONISM makes clear, the evidence for evolution can be fully compatible with religious faith. Science and religion are different ways of understanding the world. Needlessly placing them in opposition reduces the potential of each to contribute to a better future," the book says. ---------------------------- Article adapted by Medical News Today from original press release. ---------------------------- SCIENCE, EVOLUTION, AND CREATIONISM is the third edition of a publication first issued in 1984 and updated in 1999. The current book was published jointly by the National Academy of Sciences and Institute of Medicine, and written by a committee chaired by Francisco Ayala, Donald Bren Professor of Biological Sciences, department of ecology and evolutionary biology, University of California, Irvine, and author of several books on science and religion. A committee roster follows. The book was funded by the NAS, IOM, the Christian A. Johnson Endeavor Foundation, the Biotechnology Institute, and the Coalition of Scientific Societies. The National Academy of Sciences is an independent society of scientists, elected by their peers for outstanding contributions to their field, with a mandate from Congress since 1863 to advise the federal government on issues of science and technology. The Institute of Medicine was created in 1970 by the NAS to provide science-based advice on matters of biomedical science, medicine, and health. [This news release and book are available at http://national-academies.org/] Article URL: http://www.medicalnewstoday.com/articles/93309.php Main News Category: Biology / Biochemistry Also Appears In: Genetics, Medical Students / Training,