Sunday, September 21, 2008
New Review
I have reviewed the book "Atheism Explained" by David Ramsay Steele. Click here to view it.
Saturday, September 20, 2008
Another Creationist Argument Gone With the Wind
Have you ever been talking to a creationist, who knows that agriculture only began about 10,000 years ago, say something like, "What were we doing for all those tens of thousands of years before then? Why didn't we settle down sooner?"
I did not know the answer to this, until now. Via ScienceDaily:
Until recently researchers say the story of the origin of agriculture was one of a relatively sudden appearance of plant cultivation in the Near East around 10,000 years ago spreading quickly into Europe and dovetailing conveniently with ideas about how quickly language and population genes spread from the Near East to Europe. Initially, genetics appeared to support this idea but now cracks are beginning to appear in the evidence underpinning that model
Now a team led by Dr Robin Allaby from the University of Warwick have developed a new mathematical model that shows how plant agriculture actually began much earlier than first thought, well before the Younger Dryas (the last “big freeze” with glacial conditions in the higher latitudes of the Northern Hemisphere). It also shows that useful gene types could have actually taken thousands of years to become stable.
Up till now researchers believed in a rapid establishment of efficient agriculture which came about as artificial selection was easily able to dominate natural plant selection, and, crucially, as a consequence they thought most crops came from a single location and single domestication event.
However recent archaeological evidence has already begun to undermine this model pushing back the date of the first appearance of plant agriculture. The best example of this being the archaeological site Ohalo II in Syria where more than 90,000 plant fragments from 23,000 years ago show that wild cereals were being gathered over 10,000 years earlier than previously thought, and before the last glacial maximum (18,000-15,000 years ago).
The field of Archaeobotany is also producing further evidence to undermine the quick development model. The tough rachis mutant is caused by a single recessive allele (one gene on a pair or group of genes) , and this mutant is easily identifiable in the archaeological specimens as a jagged scar on the chaff of the plant noting an abscission (shedding of a body part) as opposed to the smooth abscission scar associated with the wild type brittle rachis.
I did not know the answer to this, until now. Via ScienceDaily:
Until recently researchers say the story of the origin of agriculture was one of a relatively sudden appearance of plant cultivation in the Near East around 10,000 years ago spreading quickly into Europe and dovetailing conveniently with ideas about how quickly language and population genes spread from the Near East to Europe. Initially, genetics appeared to support this idea but now cracks are beginning to appear in the evidence underpinning that model
Now a team led by Dr Robin Allaby from the University of Warwick have developed a new mathematical model that shows how plant agriculture actually began much earlier than first thought, well before the Younger Dryas (the last “big freeze” with glacial conditions in the higher latitudes of the Northern Hemisphere). It also shows that useful gene types could have actually taken thousands of years to become stable.
Up till now researchers believed in a rapid establishment of efficient agriculture which came about as artificial selection was easily able to dominate natural plant selection, and, crucially, as a consequence they thought most crops came from a single location and single domestication event.
However recent archaeological evidence has already begun to undermine this model pushing back the date of the first appearance of plant agriculture. The best example of this being the archaeological site Ohalo II in Syria where more than 90,000 plant fragments from 23,000 years ago show that wild cereals were being gathered over 10,000 years earlier than previously thought, and before the last glacial maximum (18,000-15,000 years ago).
The field of Archaeobotany is also producing further evidence to undermine the quick development model. The tough rachis mutant is caused by a single recessive allele (one gene on a pair or group of genes) , and this mutant is easily identifiable in the archaeological specimens as a jagged scar on the chaff of the plant noting an abscission (shedding of a body part) as opposed to the smooth abscission scar associated with the wild type brittle rachis.
Friday, September 19, 2008
Glorious Contingency
Here's a little essay I wrote a while back:
Stephen Jay Gould is famous for arguing that if we "replayed the tape of life" nothing even remotely similar to Homo Sapiens would emerge. He draws this conclusion from the infamous Cambrian explosion, in which many novel body plans were evolving. Some of the Cambrian fossils have an eerie other worldly look, and it is clear that if they had survived rather than Pikaia, the ancestor of all vertebrates, life on earth would be unimaginably different. Evolution is always contingent upon the step which precedes it, bulding upon and expanding what is already there. If this crucial and basic step towards vertebrate life were removed, it would follow that all the steps built upon it would cease to exist.
Critics have pointed out cases of convergent evolution and argued that if we did replay the tape of life a second time, much, though not all, would remain the same. This is wrong. Eyes, Wings, and Fins might still emerge, since they have emerged in all manner of lineages, even nonvertebrates. Yet take a look at the most famous example touted by the likes of Kenneth Miller and Daniel Dennett: The Marsupials. While it is true that striking examples of convergence exist between placental mammals and marsupials, the marsupial "mole", for instance, Stephen Jay Gould's main point remains unrebutted. The earliest mammals date to about 220 million years old, while Australia separated from Gondwana about 100 million years ago. Thus, mammals were divided geographically after 100 million years of evolution from their most primitive forms. The earliest steps in the history of placental and marsupial mammals were the same, and after they divided their evolution was (very roughly) similar. Contrast this to Stephen Jay Gould's argument that if the first step in the history of life was radically different, the steps following that would be even moreso.
Another objection to Gould's argument is that he assumes the success of the Cambrian groups as random. How do we know that there was a giant lottery going on? Perhaps it was not the luck of the draw, and there is a perfectly good reason Pikaia lived. This may be so, but consider this: If conditions were good enough for Pikaia's competitors to evolve and flourish for a time, need they be radically different for those competitors to have won the grand lottery? Secondly, it is all to easy to imagine a catastrophe, such as a landslide, wiping out most or all of the fragile vertebrate species.
Life as we know it is a glorious contingency.
Stephen Jay Gould is famous for arguing that if we "replayed the tape of life" nothing even remotely similar to Homo Sapiens would emerge. He draws this conclusion from the infamous Cambrian explosion, in which many novel body plans were evolving. Some of the Cambrian fossils have an eerie other worldly look, and it is clear that if they had survived rather than Pikaia, the ancestor of all vertebrates, life on earth would be unimaginably different. Evolution is always contingent upon the step which precedes it, bulding upon and expanding what is already there. If this crucial and basic step towards vertebrate life were removed, it would follow that all the steps built upon it would cease to exist.
Critics have pointed out cases of convergent evolution and argued that if we did replay the tape of life a second time, much, though not all, would remain the same. This is wrong. Eyes, Wings, and Fins might still emerge, since they have emerged in all manner of lineages, even nonvertebrates. Yet take a look at the most famous example touted by the likes of Kenneth Miller and Daniel Dennett: The Marsupials. While it is true that striking examples of convergence exist between placental mammals and marsupials, the marsupial "mole", for instance, Stephen Jay Gould's main point remains unrebutted. The earliest mammals date to about 220 million years old, while Australia separated from Gondwana about 100 million years ago. Thus, mammals were divided geographically after 100 million years of evolution from their most primitive forms. The earliest steps in the history of placental and marsupial mammals were the same, and after they divided their evolution was (very roughly) similar. Contrast this to Stephen Jay Gould's argument that if the first step in the history of life was radically different, the steps following that would be even moreso.
Another objection to Gould's argument is that he assumes the success of the Cambrian groups as random. How do we know that there was a giant lottery going on? Perhaps it was not the luck of the draw, and there is a perfectly good reason Pikaia lived. This may be so, but consider this: If conditions were good enough for Pikaia's competitors to evolve and flourish for a time, need they be radically different for those competitors to have won the grand lottery? Secondly, it is all to easy to imagine a catastrophe, such as a landslide, wiping out most or all of the fragile vertebrate species.
Life as we know it is a glorious contingency.
Sunday, September 14, 2008
Review of Antony Flew's book "There is a God"
Internet Infidels published my book review of Antony Flew's "There is a God"!! Click here to read it.
Saturday, September 13, 2008
AiG Idiocy on Protocells
Here is what Answers in Genesis has to say about the new protocell research:
"For now, however, the cells are unable to do much of anything: '[t]he replication isn't wholly autonomous,' according to the article, and the team must use pre-existing fatty molecules and borrow from existing life to get the nucleic acids."
And yet we know that lipid membranes can and do form under prebiotic conditions. More importantly, the article states right afterward that scientists have come up with plausible ways for RNA to form under prebiotic conditions. It even gives a link to the peer reviewed paper.
AiG sums up with this (Their comments are in italics):
So, our conclusion on this research: evolutionary scientists are trying to intelligently design
Creationists always trot out this line as if it were something clever. Yes, intelligent scientists are involved, but they are working with materials that were on the early earth. They are simply trying to find out what conditions it takes to create the first cell. Nevertheless, whatever scientists come up with has to be something that could plausibly happen on the early earth.
(but as of yet haven’t succeeded) a self-replicating organism nowhere near as complex as actual (extant) life via chemicals and mechanisms that are not agreed upon
They already have created a self replicating organism, it simply does not satisfy a strict definition of life. (See this video). I found this comment from Jeffrey Bada to be rather odd, he said: "His hope is that he'll have a complete self-replicating system in his lab in the near future."
My impression, from reading the peer reviewed article, was that these protocells were able to self replicate. I think the issue is that the strands of nucleic acids used in the experiment were not made totally from scratch (One news report says, "Despite the success of his model protocell in synthesizing a genetic polymer, Szostak says more work is needed. For one thing, he says, he hasn't yet been able to create the original strand of genetic material-only copy it"). As for the chemicals and mechanisms, the article simply shows scientists saying that these experiments only show one way in which life could originate. Who knows? Perhaps it could originate in many ways. This is a very reasonable stance to take, and it does not mean that scientists have fundamental disagreements about the conditions of the early earth- only about the conditions which brought about life.
...in the hopes that it will somehow prove their by-faith hypotheses about how a less-complex-than-real-life organism could have, maybe, given rise to life as we know it (or not) through millions of years of accidental mutation. And—even though we will never know how it “really happened,” we should take this as proof that such origin of life stories are superior to the Bible’s clear account in Genesis?
Yes, we should take these experiments more seriously than the bronze age myths of the bible that were borrowed from other cultures. And what the hell is it that AiG expects from these experiments anyway? They want these scientists to just throw a bunch of chemicals together and make a kitten. Well, sorry, but scientists have made it clear from early on that whatever the first self replicating system was, it was much simpler than even the simplest life is today (See Dawkins, 1976). Even Charles Darwin understood that when he speculated that life began "in some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, etc. present, . . . a protein compound was chemically formed, ready to undergo still more complex changes."
"For now, however, the cells are unable to do much of anything: '[t]he replication isn't wholly autonomous,' according to the article, and the team must use pre-existing fatty molecules and borrow from existing life to get the nucleic acids."
And yet we know that lipid membranes can and do form under prebiotic conditions. More importantly, the article states right afterward that scientists have come up with plausible ways for RNA to form under prebiotic conditions. It even gives a link to the peer reviewed paper.
AiG sums up with this (Their comments are in italics):
So, our conclusion on this research: evolutionary scientists are trying to intelligently design
Creationists always trot out this line as if it were something clever. Yes, intelligent scientists are involved, but they are working with materials that were on the early earth. They are simply trying to find out what conditions it takes to create the first cell. Nevertheless, whatever scientists come up with has to be something that could plausibly happen on the early earth.
(but as of yet haven’t succeeded) a self-replicating organism nowhere near as complex as actual (extant) life via chemicals and mechanisms that are not agreed upon
They already have created a self replicating organism, it simply does not satisfy a strict definition of life. (See this video). I found this comment from Jeffrey Bada to be rather odd, he said: "His hope is that he'll have a complete self-replicating system in his lab in the near future."
My impression, from reading the peer reviewed article, was that these protocells were able to self replicate. I think the issue is that the strands of nucleic acids used in the experiment were not made totally from scratch (One news report says, "Despite the success of his model protocell in synthesizing a genetic polymer, Szostak says more work is needed. For one thing, he says, he hasn't yet been able to create the original strand of genetic material-only copy it"). As for the chemicals and mechanisms, the article simply shows scientists saying that these experiments only show one way in which life could originate. Who knows? Perhaps it could originate in many ways. This is a very reasonable stance to take, and it does not mean that scientists have fundamental disagreements about the conditions of the early earth- only about the conditions which brought about life.
...in the hopes that it will somehow prove their by-faith hypotheses about how a less-complex-than-real-life organism could have, maybe, given rise to life as we know it (or not) through millions of years of accidental mutation. And—even though we will never know how it “really happened,” we should take this as proof that such origin of life stories are superior to the Bible’s clear account in Genesis?
Yes, we should take these experiments more seriously than the bronze age myths of the bible that were borrowed from other cultures. And what the hell is it that AiG expects from these experiments anyway? They want these scientists to just throw a bunch of chemicals together and make a kitten. Well, sorry, but scientists have made it clear from early on that whatever the first self replicating system was, it was much simpler than even the simplest life is today (See Dawkins, 1976). Even Charles Darwin understood that when he speculated that life began "in some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, etc. present, . . . a protein compound was chemically formed, ready to undergo still more complex changes."
Friday, September 12, 2008
New Research on the Evolution of Whales
From LiveScience:
A great deal of mystery surrounds how the anatomy of the first whales changed to propel them through the water. A key piece of that puzzle would be the discovery of when exactly the wide flukes on their powerful tails arose.
"The origin of flukes is one of the last steps in the transition from land to sea," explained vertebrate paleontologist Mark Uhen of the Alabama Museum of Natural History in Tuscaloosa.
To shed light on this mystery, Uhen analyzed new fossils that amateur bone hunters discovered exposed along riverbanks in Alabama and Mississippi. These bones once belonged to the ancient whale Georgiacetus, which swam along the Gulf Coast of North America roughly 40 million years ago, back when Florida was mostly submerged underwater. This creature reached some 12 feet in length and likely used its sharp teeth to dine on squid and fish.
The first whales known to possess flukes are close relatives of Georgiacetus that date back to 38 million years ago. But while only about 2 million years separate Georgiacetus from these other whales, Uhen now finds that Georgiacetus apparently did not possess flukes. The new 2-inch-long tail vertebra he analyzed — one of some 20 tail vertebrae the ancient whale had — is not flattened as the vertebrae near whales flukes are.
A great deal of mystery surrounds how the anatomy of the first whales changed to propel them through the water. A key piece of that puzzle would be the discovery of when exactly the wide flukes on their powerful tails arose.
"The origin of flukes is one of the last steps in the transition from land to sea," explained vertebrate paleontologist Mark Uhen of the Alabama Museum of Natural History in Tuscaloosa.
To shed light on this mystery, Uhen analyzed new fossils that amateur bone hunters discovered exposed along riverbanks in Alabama and Mississippi. These bones once belonged to the ancient whale Georgiacetus, which swam along the Gulf Coast of North America roughly 40 million years ago, back when Florida was mostly submerged underwater. This creature reached some 12 feet in length and likely used its sharp teeth to dine on squid and fish.
The first whales known to possess flukes are close relatives of Georgiacetus that date back to 38 million years ago. But while only about 2 million years separate Georgiacetus from these other whales, Uhen now finds that Georgiacetus apparently did not possess flukes. The new 2-inch-long tail vertebra he analyzed — one of some 20 tail vertebrae the ancient whale had — is not flattened as the vertebrae near whales flukes are.
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