Archive for February, 2009

Feb 27 2009

Two Stories of Human Evolution

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Two new bits of evidence published recently have allowed scientists to flesh out the picture of human evolution a bit more. The first is a collection of fossils of Australopithecus amanensis found in Ethiopia. This is a significant find because it fills in a previous gap in the fossil record.

The big picture that we have so far is that human ancestors split from chimp ancestors about 5-7 million years ago, and seem to have quickly become bipedal after they diverged.  One candidate for the earliest fossil species on the human line is Ardipithecus ramidis, which dates to about 4.4 million years ago. Fossil remains of this species are scant, but they appear to have had a dentition more similar to apes like chimps than to later hominids. They also have derived characteristic homologous with Australopithecines and cranial bones suggesting that the skull rested vertically on top of the spinal column, suggesting they were bipedal.

The next genus thought to be in the line that led to humans is Australopithecus. These include the famous Lucy specimen that is an incredibly intact fossil. Australopithecines were clearly bipedal, although less adapted to bipedalism than humans, and have other features nicely transitional from non-human apes to humans. The oldest Australopithecus is an afarensis from 3.4 million years ago. Hence the gap from 3.4 to 4.4 million years ago.

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Feb 26 2009

Want To Lose Weight? Reduce Calories.

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As a scientific skeptic I am careful to emphasize that my current position on any scientific question is tentatively based on available evidence. If new data comes in that warrants a change in my position, I will happily change it. Not only is this position scientific, it has the advantage of not tying you to a position that might be wrong. I try to become as emotionally dispassionate about specific conclusions as possible – it is only the validity of the process that I value.

But I admit I cannot help but feel a sense of satisfaction when new data supports a position I have taken on a controversial topic (a guilty pleasure, I suppose).  In this case a new study published in the New England Journal of Medicine comparing various weight loss diets supports my contention that weight loss is all about calories in vs calories out.

There has been a tremendous amount of popular marketing of diets claiming that the proportion of macronutrients – fats, protein, and carbohydrates – is important to weight loss and other health factors. For example, Atkins has made low-carb diets extremely popular. The problem has always been that the scientific data simply did not support any such claims. This did not stop the press from declaring that “Atkins is vindicated” every time a small and worthless pilot study came out showing possible short term advantage but no long term advantage, and overall very small differences in various diets. The weight of the evidence supported the conclusion that weight loss is achieved by burning more calories than are consumed, regardless of the source of those calories.

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102 responses so far

Feb 25 2009

Egnor Sinks to New Lows

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This is low, even for Dr. Michael Egnor, who has been an active apologist for the nonsensical anti-evolution propaganda over at the Discovery Institute. Egnor cannot seem to resist when he thinks he has caught someone in an error, and so he throws whatever faint whisper of logic or scholarship he has overboard (hardly noticeable, really) and sinks to new lows of intellectual buffoonery.

In this case he is responding to my discussion of the evolutionary tree of life – the fact that the fossil record and genetic evidence support the conclusion that all life is related through a pattern of branching descent. He refers to my summary of the current consensus of scientific opinion as an “astonishing gaffe.”

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105 responses so far

Feb 24 2009

Revenge of Titanoboa

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I didn’t plan to do two similar stories in a row, but this just came to my attention. There is a picture going around that purports to show a 100ft. snake swimming through a river in Borneo. The picture was allegedly taken by from a helicopter by a disaster team monitoring flood conditions.

The image is certainly provocative – but as I pointed out yesterday, before we start hypothesizing about what the picture may be we first have to confirm that it is real. Pictures are no longer acceptable as evidence at face-value. The so-called Atlantis picture from yesterday was likely an innocent artifact. This picture is unlikely to be an artifact, but it can easily be fraud.

I’m sure that the marketers at Adobe are thrilled that their brand name photo-manipulation software, Photoshop, has become the generic term for using such software to alter images.  So before we knock ourselves out trying to figure out what physical phenomenon may be in the picture we first have to confirm that it was not “photoshopped.”

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24 responses so far

Feb 23 2009

Google Atlantis

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Atlantis is one of those enduring myths that is so tenacious it provokes speculation about what is it, exactly, that makes it so irresistible. It certainly appeals to the imagination – wondering what an ancient yet advanced civilization might have been like. It also appeals to the little explorer in each of us. At a time when we can go on the computer in our living room and see high quality satellite images of the entire planet it may seem like there is nothing left to explore – no edge of the map beyond which there be dragons. A little mystery can be fun – perhaps there are hidden archaeological and historical treasures to be found, at the bottom of the ocean or under Antarctica, whatever your preference.

Ironically, Bernie Bamford, an aeronautical engineer from Chester, UK, claims he found an aerial map of Atlantis on Google Earth. What he found was what appears to be a atlantis-googlegrid-pattern of lines covering an area about the size of Wales about 620 miles off the coast of West Africa (here are the Google coordinates: 31 15’15.53N 24 15’30.53W. Bamford is quoted as saying that the grid pattern “must be man-made.” Some reports characterize the pattern as “perfect.”

Certainly perfectly straight lines and right angles are not features common in nature and they do indeed suggest a human technological origin. If you look closely at the photo you will see that the lines are not perfect – but to be fair they are close enough that the non-natural argument still holds.

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28 responses so far

Feb 21 2009

Mind and Brain on NPR

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NPR finally aired the segment they recorded with me last month. The segment is called Doubting Darwin: Debate Over The Mind’s Evolution, and features interviews with me and Dr. Egnor. The interviews were recorded separately – it was not a discussion or debate. Of course we are each very familiar with the other’s arguments, and readers of this blog will recognize most of the points made.

The segment was well produced and fair (at least from my perspective, I can’t speak for Dr. Egnor) – they used my points in context, chose reasonably representative segments, and did not sandbag me with counterpoints I was not aware of. (These are all risks when being interviewed, especially by lower quality outlets.)

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84 responses so far

Feb 17 2009

A Visit with James Randi

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I am on vacation with the family this week. This has a couple of implications for this blog. First, I will not be posting as many entries. Tomorrow I have a post at Science Based Medicine, and then my next post here will be Friday. Next week I will be back to my usual schedule. I also will not be able to moderate comments as often – so be patient.

But the good news is that I am vacationing in Florida and took the opportunity to visit James Randi at the JREF headquarters.

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6 responses so far

Feb 16 2009

Neanderthal Genome

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Scientists have completed a “first draft” of the neanderthal genome. This is exciting on many levels. One of the burning questions of paleoanthropology is the relationship between humans and our closest cousins, the Homo neanderthalensis. Debate has gone back and forth over years, but this is a debate that can be resolved with evidence.

So now that we have taken a good peek at the neanderthal genome, what do we find? Svante Paabo, speaking at the AAAS, reports that his team could not find any evidence of interbreeding between neanderthals and humans. This does not mean there was absolutely no cross-species hanky panky, but it does mean that it was rare and contributed minimally to the human genome. There still might be a mutation or two to be found contributed to the human genome from neanderthals – or contributed to the neanderthals from humans. But the big question has been answered – the two populations did not merge.

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19 responses so far

Feb 12 2009

Autism Court Ruling – Vaccines Didn’t Cause Autism

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The much awaited decision on the first test case of the Autism Omnibus was just announced – and it’s good news. They have found that the petitioners failed to make their case that vaccines caused their children’s autism, and that therefore compensation was not appropriate.

The Autism Omnibus hearings were set up to evaluate for thousands of petitions for compensation under the vaccine injury compensation program. This is a program set up in the US to compensate those who suffer adverse effects from vaccines, and it is paid for by a tax on all vaccines. This is a sensible system because it allows manufacturers to produce much needed vaccines without risking bankruptcy over fad pseudoscientific accusations – like those that took down Dow Chemical. It also more quickly and fairly compensated families, which is fair given that vaccines are somewhat compulsory in the US (although in most states it is all too easy to get an exemption).

These cases arise out of the now scientifically discredited notion that certain vaccines or something in vaccines (like thimerosal) is linked to autism. I have written extensively about this controversy, and what we can say at this time is that the scientific evidence is solidly against any link.

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40 responses so far

Feb 12 2009

Some Darwin Day News and Fun

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This will complete my brief series on evolution and creationism leading up to Darwin Day – the 200th anniversary of Darwin’s birth.

Shenanigans In Belfast

As reported by the Guardian, a museum in Belfast is planning an exhibit on Darwin. In response, Mervyn Storey, a Democratic Unionist member of the Northern Ireland assembly, warned that he will take legal action to force the museum to give equal space to a creationist exhibit. The Guardian quotes him as saying:

“They could be subject to a legal challenge under equality legislation within Northern Ireland if they chose to ignore alternative views that many people here in the Province believe in.”

I wonder to which “alternative views” Storey (a born-again Christian) is referring? Perhaps he wants to give space to the Raelian view that humans were planted on earth by aliens. The museum clearly needs to make space for an exhibit of space aliens cloning the first humans in their image. Or maybe that’s not what he had in mind.

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11 responses so far

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