Monthly Archives: February 2009

A Small Step for Homo Erectus, A Giant Leap for Humankind

Fascinating news about our ancestors from the New York Times

PRINTS SHOW A MODERN FOOT IN PREHUMANS

By JOHN NOBLE WILFORD Published: February 26, 2009

Footprints uncovered in Kenya show that as early as 1.5 million years ago an ancestral species, almost certainly Homo erectus, had already evolved the feet and walking gait of modern humans.

An international team of scientists, in a report on Friday in the journal Science, said the well-defined prints in an eroding bluff east of Lake Turkana “provided the oldest evidence of an essentially modern humanlike foot anatomy.” They said the find also added to evidence that painted a picture of Homo erectus as the prehumans who took long evolutionary strides — figuratively and, now it seems, also literally.

One of the fossilized footprints discovered in Kenya

One of the fossilized footprints discovered in Kenya

Where the individuals who made the tracks were going, or why, is beyond knowing by the cleverest scientist. The variability of the separation between some steps, researchers said, suggests that they were picking their way over an uneven surface, muddy enough to leave a mark — an unintended message from an extinct species for the contemplation of its descendants.

Until now, no footprint trails had ever been associated with early members of our long-legged genus Homo. Preserved ancient footprints of any kind are rare. The only earlier prints of a protohuman species were found in 1978 at Laetoli, in Tanzania. Dated at 3.7 million years ago, they were made by Australopithecus afarensis, the diminutive species to which the famous Lucy skeleton belonged. The prints showed that the species already walked upright, but its short legs and long arms and its feet were in many ways apelike.

Studying the more than a dozen prints, scientists determined that the individuals had heels, insteps and toes almost identical to those in humans, and that they walked with a long stride similar to human locomotion.

The researchers who made the discovery, as well as independent specialists in human origins, said the prints helped explain fossil and archaeological evidence that erectus had adapted the ability for long-distance walking and running. Erectus skeletons from East Asia revealed that the species, or a branch of it, had migrated out of Africa as early as 1.8 million years ago.

The lead author of the journal report, Matthew R. Bennett, a dean at Bournemouth University in England, analyzed the prints with a new laser technology for digitizing their precise depths and contours. The tracks were excavated over the last three years by paleontologists and students directed by John W. K. Harris of Rutgers University in collaboration with the National Museums of Kenya.

Daniel E. Lieberman, a professor of biological anthropology at Harvard who studies the evolution of human locomotion but was not a member of the research group, said the prints established what experts had suspected for some time. Erectus, he said, “probably looked much like us, both walking and running over long distances.”

Although the discoverers were cautious in attributing the prints to Homo erectus, Dr. Lieberman and other experts said in interviews that it was highly unlikely they could have been made by other known hominid contemporaries. “The prints are what you would expect from the erectus skeleton we have,” said Leslie C. Aiello, president of the Wenner-Gren Foundation for Anthropological Research, which supported the research.

William L. Junger, a paleoanthropologist at Stony Brook University in New York, said the footprints were further evidence that erectus had “undergone a major structural change in body plan, and it’s much like our own.” One obvious exception: the erectus brain, which was more advanced than those of previous ancestors, but was still much smaller than the Homo sapiens brain.

No erectus foot bones have been found anywhere, but other well-preserved, yet incomplete, skeletons showed the species to be taller and less robust than earlier hominids. The strides of these footsteps suggest that the individuals were an average of 5 feet, 7 inches tall; one, presumably a child, was 3 feet tall.

The site of the discovery is about five miles east of Lake Turkana, near the village of Ileret, in northern Kenya.

Dr. Harris of Rutgers said that excavations from 2005 through last year yielded scores of animal tracks as well as the erectus footprints. Geological evidence indicates that they were made on the muddy surface of a floodplain in a time of nearby volcanic eruptions. Layers of volcanic ash, mixed with silt deposits, were examined to date the finds.

The tracks were confined to two layers of sediment, vertically separated by 15 feet and about 10,000 years. The upper layer contained three footprint trails, two of two prints each and one of seven prints, as well as several isolated prints. The lower layer preserved one trail of two prints and a single isolated print.

Dr. Bennett joined the project in 2007 to make three-dimensional digital records of the footprints. He also scanned the tracks of local people who walked through soil from the excavations. He said their prints, like those of other modern humans, were remarkably similar to the erectus prints. Later, digital images of casts of the prints from Laetoli showed marked differences in foot shapes.

Anatomists analyzing the Ileret prints said the heel, instep, balls of the foot and short toes were considerably distinct from the prints discovered in Tanzania and almost identical to modern humans. Most obviously, the big toe is in line with the rest of the toes, not angling away from other toes, as on an afarensis foot.

The footprints discovered in Kenya, researchers said, indicated that the erectus foot functioned much as a human foot does: the heel contacts the ground first; weight transfers along the arch to the ball of the foot; and the push-off is applied by the forefoot. In apes and apparently earlier hominids, this force comes from the midfoot.

The discovery is “even more explicit evidence,” Dr. Harris said, that the erectus species extended its range into more diversified habitats, camping and discarding stone tools at sites far from the sources of the stone.

Advertisements

Leave a comment

Filed under Athesim, humanism, religion, science

Nature is just too cool for words – A fish with a see-through head

This is so cool.

It’s a reprint of an article from Live Science.

_______________________________________________

STRANGE FISH HAS SEE-THROUGH HEAD

Live Science

posted: 23 February 2009 03:01 pm ET

A bizarre deep-water fish called the barreleye has a transparent head and tubular eyes. Since the fish’s discovery in 1939, biologists have known the eyes were very good at collecting light. But their shape seemed to leave the fish with tunnel vision.

The barreleye (Macropinna microstoma) has extremely light-sensitive eyes that can rotate within a transparent, fluid-filled shield on its head. The fish's tubular eyes, well inside the head, are capped by bright green lenses. The eyes point upward (as shown here) when the fish is looking for food overhead. They point forward when the fish is feeding. The two spots above the fish's mouth are not eyes: those are olfactory organs called nares, which are analogous to human nostrils. Credit: © 2004 MBARI

The barreleye (Macropinna microstoma) has extremely light-sensitive eyes that can rotate within a transparent, fluid-filled shield on its head. The fish's tubular eyes, well inside the head, are capped by bright green lenses. The eyes point upward (as shown here) when the fish is looking for food overhead. They point forward when the fish is feeding. The two spots above the fish's mouth are not eyes: those are olfactory organs called nares, which are analogous to human nostrils. Credit: © 2004 MBARI

Now scientists say the eyes rotate, allowing the barreleye to see directly forward or look upward through its transparent head.

The barreleye (Macropinna microstoma) is adapted for life in a pitch-black environment of the deep sea, where sunlight does not reach. They use their ultra-sensitive tubular eyes to search for the faint silhouettes of prey overhead.

Scientists had thought the eyes were fixed in an upward gaze, however. This would make it impossible for the fish to see what was directly in front of them, and very difficult for them to capture prey with their small, pointed mouths.

Bruce Robison and Kim Reisenbichler of the Monterey Bay Aquarium Research Institute use videos from the institute’s remotely operated vehicles (ROVs) to study barreleyes off Central California. At depths of 2,000 to 2,600 feet (600 to 800 meters), the ROV cameras typically showed these fish hanging motionless in the water, their eyes glowing a vivid green in the ROV’s bright lights. The video also revealed a previously undescribed feature of these fish — its eyes are surrounded by a transparent, fluid-filled shield that covers the top of the fish’s head.

Most existing descriptions and illustrations of this fish do not show its fluid-filled shield, probably because this fragile structure was destroyed when the fish were brought up from the deep in nets.

In this image, although the barreleye is facing downward, its eyes are still looking straight up. This barreleye is about 6 inches (140 cm) long. Credit: © 2004 MBARI

In this image, although the barreleye is facing downward, its eyes are still looking straight up. This barreleye is about 6 inches (140 cm) long. Credit: © 2004 MBARI

Robison and Reisenbichler were fortunate to bring a net-caught barreleye to the surface alive. Over several hours in an aquarium on the ship, they were able to confirm that the fish rotated its tubular eyes as it turned its body from a horizontal to a vertical position.

Barreleyes, just a few inches long, are thought to eat small fishes and jellyfish. The green pigments in their eyes may filter out sunlight coming directly from the sea surface, helping the barreleye spot the bioluminescent glow of jellies or other animals directly overhead. When it spots prey (such as a drifting jelly), a barreleye rotates its eyes forward and swims upward, in feeding mode.

The findings were detailed recently in the journal Copeia.

____________________________

Here’s a link to a video of this amazing creature: http://www.livescience.com/common/media/video/player.php?videoRef=LS_090223_barreleye

Leave a comment

Filed under Athesim

Why scientific thinking is good for everyone, not just scientists – Part 2 – Alternative Medicine

“…at the heart of science is an essential balance between two seemingly contradictory attitudes – an openness to new ideas, now matter how bizarre or counterintuitive, and the most ruthlessly sceptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense.”

Carl Sagan

Evidence-based medicine has revolutionized medical practice, transforming it from an industry of charlatans and incompetents into a system of healthcare that can deliver such miracles as transplanting kidneys, removing cataracts, combating childhood diseases, eradicating smallpox and saving literally millions of lives each year.”

Simon Singh & Edzard Ernst

I have just finished reading Simon Singh and Edzard Ernst’s excellent book, Trick or Treatment: The Undeniable Facts About Alternative Medicine. This book demonstrates the value of ‘scientific thinking’ for real life. Singh is a best-selling author and science journalist, while Ernst is a professor of complementary medicine at the University of Exeter and author of The Oxford Handbook for Complementary Medicine.b128hb_lg

In their book, Ernst and Singh examine in depth four common alternative medicine treatments: acupuncture, homeopathy, chiropractic therapy, and herbal medicine (they also have an appendix that provides one page summaries of their conclusions for 36 other forms of alternative medicine). Their goal is to take as critical and unbiased a look as possible at alternative medicine therapies and determine their actual effectiveness and safety. As a professor of complementary medicine, Ernst might be expected to have a bias in favour of alternative medical therapies, but he has a thoroughgoing commitment to following where the best evidence leads.

The first chapter of the book is entitled, “How do you determine the truth?” The focus of this chapter is on the discovery and development of the practice of controlled clinical trials. The authors point out that prior to the invention of this technique for evaluating the true effectiveness of medical interventions, more people died under the treatment of doctors than were helped. The history of blood letting as a cure-all intervention is a case in point that they describe in detail, noting that it was probably bloodletting that killed George Washington! Bloodletting was standard practice and was based on a faulty understanding of human physiology — the four ‘humours’ — that had been believed for centuries.

Interestingly, the first real “clinical trial” that we know of led to the discovery of citrus fruit as a cure for scurvy in the mid 1700s. Although initially scoffed at by many of his peers, James Lind, the man who discovered this cure, seems to have been the first to conduct an actual controlled study. Ultimately, his evidence overcame the prejudice of other doctors and, once the practice became widespread, the distribution of fruit or lemon juice on ships ended the devastation brought by scurvy. A second early example of a formal clinical trial took place in the early 1800s, where this new approach was applied to the practice of bloodletting. In this case, Alexander Hamilton proved conclusively that bloodletting was not only ineffective against the conditions for which it was applied, but that the death rate for those who received this treatment was 10 TIMES that of those who did not!

Slowly, the practice of evidence-based medicine began to become the norm. And this has been a major boon for all. Ernst and Singh point out:

Prior to the clinical trial, a doctor decided his treatment for a particular patient by relying on his own prejudices, or on what he had been taught by his peers, or on his misremembered experience of dealing with a handful of patients with a similar condition. After the advent of the clinical trial, doctors could choose their treatment for a single patient by examining the evidence from several trials, perhaps involving thousands of patients. There was still no guarantee that a treatment that had succeeded during a set of trials would cure a particular patient, but any doctor who adopted this approach was giving his patient the best possible chance of recovery…. The clinical trial helped give birth to modern medicine, which has enabled us to live longer, healthier, happier lives.

In this chapter, the authors make three key points related to my topic of why scientific thinking is good for everyone, not just scientists when it comes to determining what medical therapies you and I should use.

First, even when we don’t understand all the mechanisms behind why a particular medical intervention works, the emphasis in evidence-based medicine is primarily on whether or not a particular medical therapy actually works (as opposed to a positive outcome being either the result of a placebo effect or simply the natural course of healing for a particular illness or disease) and whether or not it is safe. This suggests that the results of good evidence-based research should be taken very seriously, because the results are concerned with whether or not the medical intervention being studied actually works or not. It’s not about what the researchers think of the philosophy behind the intervention. It’s about whether or not that intervention works and is safe. Using medical therapies that have not been well tested means you are using something that may not actually work and may not be safe. Natural does not necessarily mean safe (remember it was ‘natural’ hemlock that Socrates swallowed to kill himself!).

Second, the methodology of the study matters greatly. There are several criteria for establishing validity for the results of a medical study. One is that it be a controlled study, meaning that separate groups of patients are treated similarly except for the item being tested. This is done to rule out / minimize other possible factors that could influence patient outcomes (for example, if one group is treated by a caring doctor in a pleasant surrounding and the other is treated by a grump in a sterile lab, the possibility of different placebo effects from the therapeutic relationship taints the results). Another factor is that it be randomized. In other words, participants in the different groups need to be assigned on a random basis. Yet another factor is that the study be double-blinded. This refers to the fact that the patients being tested do not know if they are being given the real intervention or a placebo and the researchers do not know whether they are administering the real intervention or a placebo. Other studies of the placebo affect tell us that even if a patient is unaware that they are being given the “real” treatment, if the one administering it knows, their non-verbals are often very different than if they are administering a placebo. The impact of that non-verbal language has been found to have a strong influence on creating a placebo effect. The last factor for determining the validity of a study’s results is the size of the study. If there is a very small number of individuals being used, it is very hard to determine if the results are truly significant or merely chance.

When evaluating a study of any medical therapy (conventional or alternative) it is important to determine if these critieria have been met. Studies that do not meet them are generally not very reliable. The more these criteria are demonstrated to have been met, the more we can rely on the results. It is important to note that pharmaceuticals do have to meet these criteria in order to be approved by the FDA in the States and Health Canada in Canada. Alternative medicine (homeopathic and herbal remedies) do not. Fortunately, many alternative therapies are now being subjected to well-designed studies that do meet these criteria. Singh’s and Ernst’s book discusses the results of those studies.

Third, the medical field is open to new therapies that work, wherever they arise from. As the authors point out, had the term ‘alternative medicine’ been in existince when James Lind did his study on scurvy, oranges and lemons might well have been labeled as such, as they were natural remedies that were not backed by a plausible theory. But the evidence was ultimately incontrovertible. Only much later did the biology explaining the relationship between scurvy and vitamin C deficiency arise. While there may be a natural tendency for many individual doctors to resist new therapies, ultimately, evidence triumphs. So, alternative medicine becomes conventional medicine when it is demonstrated through controlled studies to be both effective and safe. There is no medical conspiracy against alternative medicine. It is simply the demand that alternative therapies be evaluated through controlled studies that is the issue.

The upshot of this is that if we want to avail ourselves of the very best treatments (conventional or alternative) it is important to use scientific thinking, particularly in demanding and evaluating well-designed controlled studies that provide evidence of a treatment’s efficacy and safety.

To do otherwise can lead to:

  • a waste of money (both your own and government subsidies).
  • settling for only a placebo effect (when you could have a real effect from a proven intervention and the placebo effect on top of it!).
  • possible harm to oneself or those who you take for treatment.

I encourage your to read Singh’s and Ernst’s book and to apply scientific thinking to all medical practices — conventional and alternative alike.

3 Comments

Filed under Athesim, health, humanism, politics, religion, science, social commentary

Ultimate Praying Championship

This is both hilarious and sad at the same time.

Leave a comment

Filed under Athesim

Gravity is just a theory. Let’s teach the controversy.

I came across an old article from The Onion that does a wonderful job of highlighting the idiocy of the “teach the controversy” tactic of creationists in trying to get creationism into science classes. Hope it brings a smile to your face.

____________________________________________

EVANGELICAL SCIENTIST REFUTE GRAVITY WITH NEW ‘INTELLIGENT FALLING’ THEORY

KANSAS CITY, KS—As the debate over the teaching of evolution in public schools continues, a new controversy over the science curriculum arose Monday in this embattled Midwestern state. Scientists from the Evangelical Center For Faith-Based Reasoning are now asserting that the long-held “theory of gravity” is flawed, and they have responded to it with a new theory of Intelligent Falling.evangelical-scientists-c

“Things fall not because they are acted upon by some gravitational force, but because a higher intelligence, ‘God’ if you will, is pushing them down,” said Gabriel Burdett, who holds degrees in education, applied Scripture, and physics from Oral Roberts University.

Burdett added: “Gravity—which is taught to our children as a law—is founded on great gaps in understanding. The laws predict the mutual force between all bodies of mass, but they cannot explain that force. Isaac Newton himself said, ‘I suspect that my theories may all depend upon a force for which philosophers have searched all of nature in vain.’ Of course, he is alluding to a higher power.”

Founded in 1987, the ECFR is the world’s leading institution of evangelical physics, a branch of physics based on literal interpretation of the Bible.

According to the ECFR paper published simultaneously this week in the International Journal Of Science and the adolescent magazine God’s Word For Teens!, there are many phenomena that cannot be explained by secular gravity alone, including such mysteries as how angels fly, how Jesus ascended into Heaven, and how Satan fell when cast out of Paradise.

The ECFR, in conjunction with the Christian Coalition and other Christian conservative action groups, is calling for public-school curriculums to give equal time to the Intelligent Falling theory. They insist they are not asking that the theory of gravity be banned from schools, but only that students be offered both sides of the issue “so they can make an informed decision.”

“We just want the best possible education for Kansas’ kids,” Burdett said.

Proponents of Intelligent Falling assert that the different theories used by secular physicists to explain gravity are not internally consistent. Even critics of Intelligent Falling admit that Einstein’s ideas about gravity are mathematically irreconcilable with quantum mechanics. This fact, Intelligent Falling proponents say, proves that gravity is a theory in crisis.

“Let’s take a look at the evidence,” said ECFR senior fellow Gregory Lunsden.”In Matthew 15:14, Jesus says, ‘And if the blind lead the blind, both shall fall into the ditch.’ He says nothing about some gravity making them fall—just that they will fall. Then, in Job 5:7, we read, ‘But mankind is born to trouble, as surely as sparks fly upwards.’ If gravity is pulling everything down, why do the sparks fly upwards with great surety? This clearly indicates that a conscious intelligence governs all falling.”

Critics of Intelligent Falling point out that gravity is a provable law based on empirical observations of natural phenomena. Evangelical physicists, however, insist that there is no conflict between Newton’s mathematics and Holy Scripture.

“Closed-minded gravitists cannot find a way to make Einstein’s general relativity match up with the subatomic quantum world,” said Dr. Ellen Carson, a leading Intelligent Falling expert known for her work with the Kansan Youth Ministry. “They’ve been trying to do it for the better part of a century now, and despite all their empirical observation and carefully compiled data, they still don’t know how.”

“Traditional scientists admit that they cannot explain how gravitation is supposed to work,” Carson said. “What the gravity-agenda scientists need to realize is that ‘gravity waves’ and ‘gravitons’ are just secular words for ‘God can do whatever He wants.'”

Some evangelical physicists propose that Intelligent Falling provides an elegant solution to the central problem of modern physics.

“Anti-falling physicists have been theorizing for decades about the ‘electromagnetic force,’ the ‘weak nuclear force,’ the ‘strong nuclear force,’ and so-called ‘force of gravity,'” Burdett said. “And they tilt their findings toward trying to unite them into one force. But readers of the Bible have already known for millennia what this one, unified force is: His name is Jesus.”

the_onion

1 Comment

Filed under Athesim, humanism, politics, religion, science, social commentary

Samuel L. Jackson, run for your life!

If you are one of those who is afraid of snakes, then be glad this one is now extinct!
Titanoboa - Extinct 43-foot long snake

Titanoboa - An extinct 43-foot long snake from 60 million years ago

You gotta love a snake named TITANABOA.

Here’s a reprint of an article about Titanaboa from the Times Online

_________________________________________

February 5, 2009
GIANT TITANABOA SNAKE RULED THE EARTH AFTER THE DINOSAURS

A titanic snake that snacked on crocodiles and was longer than a London bus has been identified as the top predator to walk, or at least slither, the land when the dinosaurs disappeared.

It weighed 1.25 tonnes and with a length of 45 feet or more it would have been able to take on and eat pretty much any other animal it came across.

The newly discovered type of snake, named Titanoboa in honour of its immense size, was for 10 million years the largest land predator on earth.

At least 28 individual specimens have been uncovered in Colombia and, with all of them being around 40 feet long, researchers said it is likely the species could have reached much further than 45 feet.

Remains of Titanoboa cerrejonensis were found in a layer of rock at the Cerrejon Coal Mine, one of the largest open-pit mines in the world.

Fossils recovered from the site over the last five years have given researchers the most detailed picture yet of life in tropical South America in the years following the disappearance of the dinosaurs.

Alongside the enormous snakes, which were so wide it would have been a squeeze for them to get through a doorway, were fossils of turtles and giant crocodile-like dyrosaurs.

Other fossil finds, including fish, gastropods and plants such as palms, are providing researchers with their first glimpses of the tropical ecosystem that laid the foundations for the Amazon forest.

Jonathan Bloch, of the University of Florida, was one of the researchers who analysed the remains of the snake, the biggest that ever lived.

He said: “It was not only the biggest predator in the region, as far as we know, but it was the largest terrestrial vertebrate known on the face of the planet for at least 10 million years.

“It could have eaten pretty much anything that came its way. If we had to guess, it probably ate a lot of fish and crocodyliforms.

“It is possible that the extinction of the dinosaurs 65 million years opened up the opportunity for the evolution of another top-predator such as Titanoboa.”

He added: “Truly enormous snakes really spark people’s imagination, but reality has exceeded the fantasies of Hollywood. The snake that tried to eat Jennifer Lopez in the movie Anaconda is not as big as the one we found.”

Carlos Jaramillo, of the Smithsonian Institution in Panama, said the specimens uncovered from the mine are likely to have been merely average in size, meaning that some individuals would have been much bigger.

The reticulated python, from South East Asia, is the longest living species recorded, according to Guinness World Records, with one individual reaching almost 33 feet long but the average length for the species is only 20 feet.

The size of the cold-blooded Titanoboa indicated to researchers that the tropical coastal river system it occupied would have been warmer than the tropics today. Using the snake’s proportions they worked out that the tropics 60 million years ago would have been about 32C, some 4C warmer than now.

Jason Head, of the University of Toronto in Canada and the Smithsonian Institution, said as the findings were published in the journal Nature: “The discovery of Titanoboa challenges our understanding of past climates and environments, as well as the biological limitations on the evolution of giant snakes.”

1 Comment

Filed under Athesim, environment, humanism, religion, science

Listen to my debate with Ray Comfort on Creation versus Evolution

Hi everyone. Happy Darwin Day!

This morning I had the opportunity to debate the Creationist, Ray Comfort on the John Oakley show on AM640 Radio in Toronto. Here’s an MP3 of the debate.

ray-comfort-scott-campbell-february-12-2009

14 Comments

Filed under Athesim