DNA that is thought to be more than a million years old has been discovered in the Bering Sea. (illustration by Lightspring via shutterstock.com)Over the weekend, I read a fascinating paper published in Geology, the peer-reviewed journal of the Geological Society of America. The authors of the paper report on their attempts to extract DNA from the sediments found at the bottom of the Bering Sea. They were successful in their attempts to find DNA, even in sediments that are supposed to be 1.4 million years old! This is a rather surprising discovery, since the half-life of DNA in bone is supposed to be about 521 years. In fact, the experiments done to obtain that half-life indicate that even at very low temperatures, no meaningful DNA could be extracted from bone after 1.5 million years.
So why is it surprising that the authors of this study found DNA in sediments that are supposed to be “only” 1.4 million years old? There are at least two reasons. First, wet sediment should accelerate the decay of biological molecules (including DNA) compared to the inside of a bone. Thus, DNA should become undetectable much earlier in wet sediment. Second, their results indicate that there would still be DNA found in much “older” sediments, because the “older” the sediment in their study, the more the DNA seem to resist decay.
But wait a minute. This is wet sediment. All manner of microorganisms can infiltrate wet sediment. How do we know that this DNA has really been in the sediment since it was formed? Couldn’t the DNA they detected be from microorganisms that recently started living there? That’s one of the clever aspects of this experiment. The authors looked at DNA that is found in the chloroplasts of cells that do photosynthesis! Since such organisms require light to survive, they wouldn’t have any reason to infiltrate the dark sediments. Even if they did get into those sediments for some reason, they would die in the upper layers, so the deeper (and therefore older) sediments definitely would not harbor any recent microorganisms that had such DNA.
In the end, it seems to me that they really did extract from the sediment DNA that had been there since that sediment had formed. That’s interesting enough, but there is something even more fascinating about what the authors found.
Galileo’s thermometer (left) and a closeup of the tube (right).If you read my two previous posts (here and here), you know that my wife and I were recently in Italy, and I was really inspired by some of the things I saw. The art and history are amazing, but for me, one of the major highlights of this visit to Italy was seeing the Galileo Museum. It is filled with scientific instruments and lecture demonstration equipment from the past, and seeing those things helped me to understand the sheer genius of the natural philosophers (scientists) who learned an enormous amount about Creation without the help of fancy, technological gadgets. Instead, they relied on their creativity and their physical insight.
Consider, for example, the glass piece pictured on the far left. It consists of a small vessel, a long, narrow tube rising up from the vessel, and a small bulb at the top of the tube. Believe it or not, that’s a thermometer. Actually, it is more properly called a “thermoscope,” and the first one was designed by Galileo (with the help of some other natural philosophers) in 1593.* Until that time, it was difficult to make any systematic measurement of temperature. People could tell whether it was hot, warm, cool, or cold, of course, but they couldn’t make precise measurements of how hot, warm, cool, or cold it was.
In the late 1500s, Galileo came up with an ingenious solution. He understood that air expanded when it was warmed and contracted when it was cooled. He decided to use that fact to get an accurate measurement of the change in temperature. He designed a device similar to the one above, in which water filled the bottom vessel and ran partway up the thin tube. When the surroundings warmed up, the air above the water (in the tube and in the bulb at the top) expanded, and that pushed the water down the tube. When the surroundings cooled, the air above the water contracted, and that pulled water up the tube.
In other words, the higher the water climbed in the tube, the lower the temperature. By making tiny marks on the side of the tube (shown in the right-hand portion of the picture at the top of this post), he could assign a number to the water’s height. This allowed him to accurately measure changes in temperature. In my elementary science book, Science in the Scientific Revolution, I have students make a very simple version of Galileo’s thermometer with water, a glass, and a plastic bottle.
A clever variation on Galileo’s thermometer.A major drawback of Galileo’s thermometer is that it must be very tall to measure large changes in temperature. While at the Galileo museum, however, I saw a very clever way of getting around that problem, which is shown in the picture on the left. Instead of a tall, straight tube, this thermometer’s tube is a spiral. That way, the water still can travel a long distance through the tube, but the device isn’t absurdly tall. As soon as I saw this device, I thought, “Of course. What an ingenious way of getting around the height problem.”
Despite the fact that I understood exactly how this variation on Galileo’s thermometer would work and why it was superior to the original design, I doubt that I would have ever come up with it on my own. I’m simply not that clever. However, Galileo and the natural philosophers of his day were. The more I learn about people like Galileo, the more I appreciate how intelligent the great thinkers of the past were. Contrary to popular belief, I think it’s possible that they were actually smarter than we are today.
NOTE:
*Please note that a device like this one is often called a “Galileo thermometer,” but Galileo had nothing to do with its design. Return to Text
The thyroid gland is an important part of the endocrine system.On March 11 of 2011, the most powerful earthquake known to have hit Japan struck near the east coast of Honshu. The earthquake generated a tsunami that reached a height of more than 130 feet. One of the many things that happened as a consequence of the disaster is that some of the reactors at the Fukushima Daiichi Nuclear Power Plant went into meltdown, and radioactive substances were leaked into the ocean and released into the air. People in a 12-mile radius around the power plant were evacuated. I have written several posts about the incident (here, here, here, here, and here), and I will continue to do so whenever new information comes to light.
Much of the discussion about the nuclear power plant disaster revolves around its long-term consequences. Since we know increased exposure to radiation can lead to an increase in cancer risk, it is natural to think that there will be an increase in cancer rates for people who were living or are living near the disaster site. Thyroid cancer is particularly sensitive to a common radioactive product of nuclear power plants, so it is assumed that thyroid cancer rates will climb in Fukushima. Indeed, a recent study shows a significant, persistent increase in thyroid cancers in the Ukraine that can be directly tied to the Chernobyl nuclear power plant disaster of 1986.1
Two of my previous posts (here and here) discussed the projected increase in cancer rates as a result of the Fukushima Daiichi disaster, and the balance of the evidence seemed to indicate that the increase would be rather small. However, in order to get a more direct measurement of thyroid cancers resulting from the disaster, Japanese authorities decided to screen all 368,651 Fukushima residents who were under 18 at the time of the disaster. An advanced technique (ultrasound) was used, and the results were surprising!
A reconstruction of Homo naledi’s skull (click for credit)Last September, the media was abuzz about a group of fossils which was supposed to represent a new species: Homo naledi. The fossils were special in many respects, but there were two that stood out: First, the fossils had characteristics that indicated they might be related to modern humans. Second, they looked like they were the result of deliberate burial, which indicates distinctly human behavior.
After reading the scientific papers that had been published regarding the fossil, I wrote a blog post about it. I was very skeptical of the authors’ interpretation that the fossils represented some species of ancient human. To my untrained eye, the fossils seemed to be characteristic of extinct apes, like those found in the genus Australopithecus. In addition, it was hard for me to believe that the collection of fossils even belonged to a single species. There seemed to be too many variations among the fossils, especially when it came to the skulls. Of course, I was quick to point out:
Now please understand that I am not a paleontologist. I am not even a biologist. I am simply a nuclear chemist who has taken an interest in the creation/evolution controversy. As a result, you need to take my comments for what they are worth.
I have been following the scientific papers that have been published since September, and I think I can unequivocally say that my comments weren’t worth very much. Because of several different analyses (both in the secular and creationist literature), I have changed my mind. Once again, who knows how much this conclusion is worth, but I now think that the balance of the scientific evidence indicates that Homo naledi is a single species, and it is probably human.
A diagram showing how a stem cell in bone marrow becomes different types of blood cells. (click for credit)
In a 2003 speech, John Kerry complained about the Bush administration, saying:
Nothing illustrates this administration’s anti-science attitude better than George Bush’s cynical decision to limit research on embryonic stem cells.
During the heat of the “stem cell wars,” this was a common refrain. Life-saving treatments could be produced with embryonic stem cells, and anyone who questioned whether or not it was morally acceptable to destroy one life in order to experiment with saving another was “anti-science.” Never mind that there are stem cells in everyone’s body, commonly called adult stem cells, and those stem cells also have the potential to cure illnesses. Everyone “knew” that using embryonic stem cells would be better.
What’s the difference between embryonic stem cells and adult stems cells? Well, most of the cells in your body have specific tasks. Your skin cells perform one set of tasks, while your muscle cells perform another set of tasks, your liver cells another set of tasks, etc., etc. These cells have all “specialized” so they can perform their tasks efficiently. A stem cell, by contrast, is a cell that hasn’t yet “specialized.” It can develop into many different cells, depending on your body’s needs.
Embryonic stem cells end up developing into all the cells that make up the body, so they are thought to be very, very flexible when it comes to what they can develop into. However, to get those stem cells, you have to kill the embryo. Adult stem cells, on the other hand have already specialized to some degree. For example, the drawing at the top of this post shows how an adult stem cell found in bone marrow can develop into various different blood cells. While that shows some serious flexibility, bone marrow stem cells don’t normally develop into wildly different cells, like skin cells. As a result, it is thought that adult stem cells aren’t as flexible as embryonic stem cells. On the positive side, however, you don’t have to kill anything to get adult stem cells.
My dad (Howard Edmund Wile) as a naval aviator.I don’t typically do many holiday posts, and when I do, they are about Christian holidays. However, later on today I am going to attend a Veterans Day ceremony in which my father, Howard Edmund Wile, will be honored for his service. He is 89 years old and was in the Navy during World War II, the Korean War, and the Vietnam War. He was a turret gunner on a PV2 Harpoon and an aviation ordnanceman on four different aircraft carriers. He retired with the rank of Chief Petty Officer. This, of course, has made me think about Veterans Day and how important it is to remember those who have served. In honor of all veterans, I give you “A Nation’s Strength” by Ralph Waldo Emerson.
What makes a nation’s pillars high
And its foundations strong?
What makes it mighty to defy
The foes that round it throng?
It is not gold. Its kingdoms grand
Go down in battle shock;
Its shafts are laid on sinking sand,
Not on abiding rock.
Is it the sword? Ask the red dust
Of empires passed away;
The blood has turned their stones to rust,
Their glory to decay.
And is it pride? Ah, that bright crown
Has seemed to nations sweet;
But God has struck its luster down
In ashes at his feet.
Not gold but only men can make
A people great and strong;
Men who for truth and honor’s sake
Stand fast and suffer long.
Brave men who work while others sleep,
Who dare while others fly…
They build a nation’s pillars deep
And lift them to the sky.
A woman uses a ‘selfie stick’ to take a selfie. (click for credit)
The headline on my Facebook feed was just too interesting to ignore: More People Die Taking Selfies Than Being Attacked by Sharks! I clicked on the photo, which sent me to this article. The first line tells you the gist of the story:
A tally of selfie-related incidents leading to deaths this year comes with a startling revelation — selfie deaths in 2015 outnumber deaths from shark attacks.
Of course, the sources seemed a bit dubious. The first was a list of shark attacks compiled in a survivors’ forum, and the second was a list of selfie-related deaths as compiled by Mashable.com. I really didn’t trust either of those sources, so I decided to look into this intriguing idea a bit more.
Finding a reliable source for shark attack deaths was pretty easy. The Florida Museum of Natural History has an ichthyology (study of fishes) department that does a pretty good job of compiling shark attacks worldwide. While they haven’t posted any preliminary data for 2015, they do have data from 2005 through 2014. As you can see from their first table, fatal shark attacks ranged from 1 in 2007 to 13 in 2011. In 2014, there were 3 fatal shark attacks.
Getting data on selfie-related deaths is a bit more difficult. The only comprehensive source I could find was a Wikipedia article entitled, “List of selfie-related injuries and deaths.” While I wouldn’t necessarily trust a list on Wikipedia, this one has references to each of the incidents, and the references seem to be reliable. As a result, I decided to do my own comparison between selfie-related deaths and shark attack deaths.
He opens up the video with a scientific error, stating:
Many, many, many, many more hundreds of eggs are fertilized than become humans. Eggs get fertilized, and by that I mean sperm get accepted by ova — a lot.
Of course, that is false. According to The Johns Hopkins Manual of Gynecology and Obstetrics,1 30-40 percent of all conceptions end in spontaneous abortion. The National Institutes of Health say that it might be up to 50%. The highest rate of spontaneous abortion occurs with in vitro fertilization, and that rate is nearly 93%.
So, in the normal course of things, maybe as many as half of conceptions end in spontaneous abortion. That means only twice as many eggs are fertilized than children who are born. Even with in vitro fertilization, about 13 times as many eggs are fertilized as children who are born. Bill Nye’s “Many, many, many, many more hundreds” statement has no scientific support whatsoever. Why does he make this false statement? Because he wants to use it to make a claim that is completely bizarre.
This statue of Gottfried Wilhelm Leibniz adorns the auditorium of the University of Göttingen. (click for credit)
I am in the midst of working on the final revisions for the third book in my new elementary science series, which is one of the many reasons I haven’t had any time to blog recently. Nevertheless, I had to take a break from the book to share two quotes of which I was recently made aware. When I finish a book, I send it to other scientists to review. This is called “peer review,” and it is an important part of the scientific process. It not only helps to find the errors that have crept into my work, it also gives me a chance to benefit from the insights of other scientists.
Well, my peer reviewers used some quotes as a part of their review, and I found two of them to be interesting enough to share with my readers here. The first comes from Gottfried Wilhelm Leibniz. He is one of the last natural philosophers I discuss in the third book of the series, and he is best known for pointing us to the conservation of mechanical energy. I discuss this in the book, but I also talk about his development of a binary system of logic, which led to the development of binary numbers. While we use binary numbers in computer systems today, one of Leibniz’s uses for binary numbers was to explain the Christian concept of creation out of nothing.
One of my peer reviewers pointed out something I didn’t know about Leibniz. He was fascinated with music and spent a great deal of time analyzing the mathematical nature of it. He said:1
Music is the pleasure the human soul experiences from counting without being aware that it is counting.
As someone who plays the piano, sings, and just loves music, I find that quote to be very interesting.
The other quote is more directly related to the concepts that are found in the book. Since it was formed during the time period covered in the book, I discuss the Royal Society, which is the world’s oldest scientific academy in continuous existence. One of my peer reviewers gave me a quote about the Royal Society, which comes from Dr. Ian G. Barbour, a physicist and theologian:2
The charter of the Royal Society instructed its fellows to direct their studies “to the glory of God and the benefits of the human race.” Robert Boyle (1627-1691) said that science is a religious task, “the disclosure of the admirable workmanship which God displayed in the universe.” Newton believed the universe bespeaks an all-powerful Creator. Sprat, the historian of the Royal Society, considered science a valuable aid to religion.
Sadly, I suspect that the Royal Society no longer follows its original charter, nor the ideals of the scientific luminaries who founded it.
REFERENCES
1. Daniel Timmons, Catherine Johnson, and Sonya McCook, Fundamentals of Algebraic Modeling: An Introduction to Mathematical Modeling with Algebra and Statistics, Brooks/Cole Cengate Learning 2010, p. 256 Return to Text
2. Ian G. Barbour, Religion and Science: Historical and Contemporary Issues, Harper 1997, p. 19 Return to Text
Pinocchio, the beloved character in Carlo Collodi’s novel, had a nose that grew when he lied.
(click for credit)
Not too long ago, the Fox network aired a reboot of Cosmos. The first version, Cosmos: A Personal Voyage, was a thirteen-part series hosted by Dr. Carl Sagan. The reboot, Cosmos: A Spacetime Odyssey, was a thirteen-part series hosted by Dr. Neil DeGrasse Tyson. While both series were mostly about science, they each mentioned the history of science from time to time. While I can’t comment on the first series, I can say without a doubt that the new series was spectacularly awful when it came to science history.
It started off badly when the first episode elevated Giordano Bruno to the status of scientific hero and martyr. The problem is, of course, that history tells a completely different story. Bruno was a champion of all sorts of strange ideas (such as that Satan would be redeemed by God and that Jesus was a magician, not the Son of God), and when he did discuss science, it was clear he didn’t understand it very well. He ended up being a martyr for magic and the occult, not for science. In addition, the serious natural philosophers of the day, like Kepler and Galileo, opposed Bruno.
Perhaps the worst treatment of science history by the new Cosmos was its discussion of Newton. Dr. Tyson actually claimed
Newton’s laws of gravity and motion revealed how the sun held distant worlds captive. His laws swept away the need for a master clockmaker to explain the precision and beauty of the solar system. Gravity is the clockmaker. [Episode 3: “When Knowledge Conquered Fear”]
Nothing could be further from the truth! In fact, the Master Clockmaker was the reason Newton came up with his Universal Law of Gravitation. Unlike the philosophers of the past, Newton believed that all motion should follow the same basic set of principles. This led to his Universal Law of Gravitation as well as his Laws of Motion. Why did Newton believe this? According to Dr. Morris Kline:1
The thought that all the phenomena of motion should follow from one set of principles might seem grandiose and inordinate, but it occurred very naturally to the religious mathematicians of the 17th century. God had designed the universe, and it was to be expected that all phenomena of nature would follow one master plan. One mind designing a universe would almost surely have employed one set of basic principles to govern related phenomena.
So rather than sweeping away the need for a Master Clockmaker, the laws he discovered were firmly rooted in the belief that there is a Master Clockmaker.
