Basic extraordinary cell biology

During a recent visit with my 12-year old daughter’s science teacher, I mentioned that I had read a few books on cell biology over the past couple of years and that I was interested in sitting in on one of the upcoming sixth grade science classes--my daughter had mentioned that they were beginning to study cell biology. I mentioned a few of the things that I had found interesting about cells to the science teacher. After noticing my enthusiasm, she retracted her invitation to watch the class and, instead, invited me to teach part of the class. A few days later I made my science teaching debut. I advised the sixth-graders that although I work as a lawyer during the day, I often read science books, and I often write about science on my website. I told them that I had no serious science education at the Catholic grade school I attended. I didn’t have any biology class at all until I was a sophomore in high school. That was mostly a nuts and bolts class taught by a Catholic nun who failed show the excitement the subject deserved. She also forgot to teach by Theodosius Dobzhansky’s maxim that "nothing in biology makes sense except in the light of evolution." I told “my” class that anyone who studies cells with any care will be greatly rewarded. Studying cells is actually autobiographical because “you are made of 60 trillion of cells.” These cells are so small that people cannot even see them. One of the students then confused trillions for millions. “Keep in mind,” I cautioned, “that a trillion is a million million.” With regard to their size, there is only one human cell--the human ovum--that you can see with the naked eye—it is much bigger than the other cells in your body. Despite its tiny size, the human ovum is so incredibly small that it’s smaller than the period at the end of this sentence. See this wonderful illustration of the size of human cells, and many other small objects.

The volume of a eukaryotic cell is typically 1000 times larger than that of a prokaryotic one. Page 28

I told the students that the study of cells is autobiographical “because each of you is a community of cells. You are a self-organized community.” [More . . . ]

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Biology is drowning in data and complexity

In the April 2010 edition of Nature (available only to subscribers online), you can read a counter-intuitive story of illustrating that more information is sometimes add confusion, rather than making things simpler. Maybe another way of putting it is that the path to understanding can often take one through phases of disorientation resulting from new influx of accurate data. This particular story, by Erika Check Hayden, titled "Life Is Complicated," considers what has happened in the field of biology subsequent to the Human Genome Project. Prior to the Project, many biologists guessed that the human genome contained about 100,000 genes that coded for proteins. At the conclusion of the project, however, we found out that only about 21,000 human genes code for proteins. One might think that this would simplify the field of biology, especially since biologists now know what many of these genes are. Many people thought that we were going to have for ourselves a clearly understandable "blueprint," of the human species. The opposite is happening, however: "It opened the door to a vast labyrinth of new questions." What kinds of questions? This article really surprised me with the vast scope of new territory opened up by the Human Genome Project. It can be summed up by Hayden's quote from biochemist Jennifer Doudna: "The more we know, the more we realize there is to know." Hayden explains that sequencing the genome undermined "the primacy of genes by unveiling a whole new classes of elements--sequences that make RNA or have a regulatory role without coding for proteins." It turns out that "much non-coding DNA has a regulatory role "that we are just beginning to understand." To illustrate how complex things have gotten, Hayden discusses what we've now learned about a single protein, "p53," which for many years was simply known as a tumor suppressor protein. Consider what we know now: In 1990, several labs found that p53 binds strictly to DNA to control transcription, supporting the traditional Jacob-Monod model of gene regulation. But as researchers broadened their understanding of gene regulation, they found more facets to p53 . . . [R]esearchers now know that p53 binds to thousands of sites in DNA, and some of the sites are thousands of base pairs away from any genes. It influences cell growth, death and structure and DNA repair. It also binds to numerous other proteins, which can modify its activity, and these protein-protein interactions can be tuned by the addition of chemical modifiers such as phosphates and methyl groups to create through a process known as alternative splicing. P53 can take nine different forms, each of which has its own activities and chemical modifiers. Biologists are now realizing that p53 is also involved in processes beyond cancer, such as fertility and very early embryonic development. In fact, it seems willfully ignorant to try to understand p53 on its own. Instead, biologists have shifted to studying the p53 network as depicted in cartoons containing boxes, circles and arrows meant to symbolize its maze of interactions. Hayden reminds us that the p53 story is one of many similar stories in post genomic-era biology. She explains that we now know that many of the signaling pathways that we thought we were close to understanding are not simple and linear but organized in vast complex networks that sometimes appear fractal. She quotes James Collins, a bio-engineer: "Kevin made the mistake of equating the gathering of information with a corresponding increase in insight and understanding." Here's another counter-intuitive result of this new dilution of information: many of our models have gotten too complex to be useful. In many cases the models themselves quickly become so complex that they are unlikely to reveal insights about the system, degenerating instead into mazes of interactions that are simply exercises in cataloging. The genome project has made biologists into kids in a big candy store: a candy store with unending aisles and endlessly deep bins of dazzling, disorienting candy, much of which is currently out of our reach. Such is the horizon of new knowledge, equal parts frustrating and tantalizing.

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Humans are so well designed!

I saw this snippet on my New Scientist RSS feed. Some researchers, investigating methods to improve IVF success rates, have discovered that contrary to popular belief, chromosomal abnormalities, and hence miscarriages, are not abnormal occurrences, but are in fact the norm.

As women age, their eggs are more likely to have the wrong number of chromosomes, which can lead to miscarriages. But when Joris Vermeersch from the Centre for Human Genetics in Leuven, Belgium, and colleagues examined 23 embryos from nine young, fertile couples who were undergoing IVF for screening purposes, they found that 21 had chromosomal abnormalities, suggesting these are in fact the norm (Nature Medicine, DOI: 10.1038/nm.1924).
I can only presume god was just being mean when he said 'go forth and multiply' - since he must have known that our ability to multiply was broken.

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Charles Darwin’s exceedingly dangerous idea

In Darwin's dangerous Idea: Evolution and the Meanings of Life, Daniel Dennett describes Darwin's idea as the "best idea anyone has ever had."

In a single stroke, the idea of evolution by natural selection unifies the realm of life, meaning, and purpose with the realm of space and time, cause and effect, mechanism and a physical law. But it is not just a wonderful scientific idea. It is a dangerous idea.

What exactly was Darwin's dangerous idea? According to Dennett, it was "not the idea of evolution, but the idea of evolution by natural selection, an idea he himself could never formulate with sufficient rigor and detail to prove, though he presented a brilliant case for it." (42) Dennett considers Darwin's idea to be "dangerous" because it has so many fruitful applications in so many fields above and beyond biology. When Dennett was a schoolboy, he and some of his friends imagined that there was such a thing as "universal acid,"

a liquid "so corrosive that it will eat through anything! The problem is: what do you keep it in? It dissolves glass bottles and stainless steel canisters as readily as paper bags. What would happen if you somehow came upon or created a dollop of universal acid? With the whole planet eventually be destroyed? What would it leave in its wake? After everything had been transformed by its encounter with universal acid, what would the world look like? Little did I realize that in a few years I would encounter an idea-Darwin's idea-bearing an unmistakable likeness to universal acid: eats through just about every traditional concept, and leaves in its wake a revolutionized world-view, with most of the old landmarks are still recognizable, but transformed in fundamental ways.

(63) Darwin's idea is powerful, indeed. Many people see it as having the power to ruin the meaning of life.

People fear that once this universal acid has passed through the monuments we cherish, they will cease to exist, dissolved in an unrecognizable and unlovable puddle of scientific destruction.

Dennett characterizes this fear is unwarranted:

We might learn some surprising or even shocking things about these treasures, but unless our valuing these things was based all long on confusion or mistaken identity, how could increase understanding of them diminish their value in our eyes? (82)

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What you can say when creationists invite you to debate them

P.Z. Myers at Pharyngula reported on an invitation sent to University of Vermont biology Professor Nicholas Gotelli, as well as Gotelli's crisp response. Here's a piece of professor Gotelli's response:

Academic debate on controversial topics is fine, but those topics need to have a basis in reality. I would not invite a creationist to a debate on campus for the same reason that I would not invite an alchemist, a flat-earther, an astrologer, a psychic, or a Holocaust revisionist. These ideas have no scientific support, and that is why they have all been discarded by credible scholars. Creationism is in the same category.

Instead of spending time on public debates, why aren't members of your institute publishing their ideas in prominent peer-reviewed journals such as Science, Nature, or the Proceedings of the National Academy of Sciences? If you want to be taken seriously by scientists and scholars, this is where you need to publish.

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