Tardigrade

From today’s Astronomy Picture of the Day, the most bizarre, alien-appearing animal on Earth, the tardigrade:

tardigrade_eyeofscience_960_thumb

Go to APOD to see it much bigger (I have only shown it as a thumbnail for copyright purposes).

I’ve thought tardigrades were pretty amazing since I first learned about them in Invertebrate Zoology a long, long time ago. Here’s APOD’s description:

Explanation: Is this an alien? Probably not, but of all the animals on Earth, the tardigrade might be the best candidate. That’s because tardigrades are known to be able to go for decades without food or water, to survive temperatures from near absolute zero to well above the boiling point of water, to survive pressures from near zero to well above that on ocean floors, and to survive direct exposure to dangerous radiations. The far-ranging survivability of these extremophiles was tested in 2011 outside an orbiting space shuttle. Tardigrades are so durable partly because they can repair their own DNA and reduce their body water content to a few percent. Some of these miniature water-bears almost became extraterrestrials recently when they were launched toward to the Martian moon Phobos on board the Russian mission Fobos-Grunt, but stayed terrestrial when a rocket failed and the capsule remained in Earth orbit. Tardigrades are more common than humans across most of the Earth. Pictured above in a color-enhanced electron micrograph, a millimeter-long tardigrade crawls on moss.

I didn’t know that tardigrades even have their own phylum.

Grace and Peace

Jesus is for geologists (and other scientists)

I’ve always known that Jesus is for geologists, as well as for biologists, chemists, physicists, archeologists, astronomers, and all other sorts of scientists.

There are, of course, many Christians who are scientists, and many scientists who are Christians. As a graduate student in geology, I found rich fellowship with a half dozen Christian geologists-in-training, and there was a Christian on the faculty of the department as well.

Davis Young, a Christian geology professor (retired), and author of The Bible, Rocks and Time, Christianity and the Age of the Earth, and Mind over Magma: the Story of Igneous Petrology, has written what he considers to be his most important book: Good News for Science: Why Scientific Minds Need God.

The summary on Barnes & Noble reads:

Bridging the fields of natural science and religion, Good News for Science: Why Scientific Minds Need God invites members of the professional scientific community, graduate, undergraduate, and high school science students, science teachers, and members of the general public who are interested in the natural sciences to embrace the Christian faith personally. Employing the theme of good news, this book challenges readers to ponder the question of life after death as a gateway to the overall claim that Christianity, at its best and most consistent, bears good news for both science and the scientist. On the one hand, Christianity, far from being antithetical to science, supplies the rational foundation that makes the scientific enterprise possible. On the other hand, the central message of Christianity brings a firm hope to scientists as individual persons in meeting their deepest needs and desires for genuine significance, purpose, goodness, forgiveness, justice, and relationship with the Creator. In presenting his case, the author eschews pseudo-science and treats with great respect the discoveries of contemporary mainstream natural science, including an ancient universe and Earth, biological evolution, and the standard model of cosmology. The text adopts an informal, personal, conversational style. Good News for Science will be of interest not only to the general scientific community but also to Christians who are seeking a resource to use in presenting Christian faith to scientifically knowledgeable individuals.

As the review says, this would be a great book for

  • Professional scientists
  • Students of science, at either the undergraduate or graduate levels
  • High school teachers and students
  • Members of the general public.

Buy this book at Barnes & Noble or Amazon.

Grace and Peace

C.S. Lewis, evolutionist

Dr. Jay Wile has an excellent summary of C.S. Lewis’s beliefs about evolution on his Proslogion blog: Another Point About C.S. Lewis.

To summarize the summary:

  • Lewis refused to join or endorse the Evolution Protest Movement, even though it was led by a personal friend.
  • His writings state acceptance of biological evolution [and, I should add, an ancient Earth (and Mars!)].
  • Lewis believed that evolution posed little threat to Christianity.
  • Lewis didn’t even believe in a literal Adam and Eve
  • Despite these beliefs, most would consider Lewis very orthodox in his Christian beliefs.

Grace and Peace

Arsenic in DNA – maybe

Figure 1 -- Phosphorus and arsenic on the periodic table.

News of surprising biochemistry: Thriving on Arsenic (NASA Astrobiology Magazine)

NASA microbiologist Felisa Wolfe-Simon has discovered bacteria that apparently can use arsenic in its DNA in place of phosphorus. Most biochemistry can be done with six elements: carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur (CHONPS). Smaller amounts of a variety of other elements are also necessary to varying degrees depending on the organism, such as sodium, calcium, iron, and magnesium. Arsenic is similar enough to phosphorus (same column in the periodic table, Figure 1) that within these bacteria it may be able to play the same role.

From the Astrobiology Magazine article:

The recent discovery by Felisa Wolfe-Simon of an organism that can utilize arsenic in place of phosphorus, however, has demonstrated that life is still capable of surprising us in fundamental ways. The results of her research were published December 2 on Science Express and subsequently in the journal Science.

The organism in question is a bacterium, GFAJ-1, cultured by Wolfe-Simon from sediments she and her colleagues collected along the shore of Mono Lake, California. Mono Lake is hypersaline and highly alkaline. It also has one of the highest natural concentrations of arsenic in the world.

On the tree of life, according to the results of 16S rRNA sequencing, the rod-shaped GFAJ-1 nestles in among other salt-loving bacteria in the genus Halomonas. Many of these bacteria are known to be able to tolerate high levels of arsenic.

But Wolfe-Simon found that GFAJ-1 can go a step further. When starved of phosphorus, it can instead incorporate arsenic into its DNA, and continue growing as though nothing remarkable had happened.

“So far we’ve showed that it can do it in DNA, but it looks like it can do it in a whole lot of other biomolecules” as well, says Wolfe-Simon, a NASA research fellow in residence at the USGS in Menlo Park, California.

The article describes the methods used to purify the DNA, to ensure that the arsenic was truly incorporated into the structure of the DNA rather that being associated with other molecules. Not all, however, are convinced.

But Steven Benner, a distinguished fellow at the Foundation for Applied Molecular Evolution in Gainesville, FL, remains skeptical. If you “replace all the phosphates by arsenates,” in the backbone of DNA, he says, “every bond in that chain is going to hydrolyze [react with water and fall apart] with a half-life on the order of minutes, say 10 minutes.” So “if there is an arsenate equivalent of DNA in that bug, it has to be seriously stabilized” by some as-yet-unknown mechanism.

Benner suggests that perhaps the trace contaminants in the growth medium Wolf-Simon uses in her lab cultures are sufficient to supply the phosphorus needed for the cells’ DNA. He thinks it’s more likely that arsenic is being used elsewhere in the cells, in lipids for example. “Arsenate in lipids would be stable,” he says, and would “not fall apart in water.” What appears in Wolfe-Simon’s gel-purified extraction to be arsenate DNA, he says, may actually be DNA containing a standard phosphate-based backbone, but with arsenate associated with it in some unidentified way.

Microbiologists over the past few decades have discovered bacteria and archaea in increasingly hostile places, such as hot springs and deep in Earth’s crust. This has spurred on the hope that other worlds (e.g. Mars, Titan) also have places that would be suitable for bacterial life. The possibility of bacteria that can live with a chemical foundation other than CHONPS indicates that life might thrive in places where we otherwise would not have expected it to.

This discovery may not completely redefine life as we know it, but it does (if proven to be true) add one more bizarre thing that life can do.

Grace and Peace

Pleistocene Park

From Yahoo! News/AP — One scientist’s hobby: recreating the ice age

CHERSKY, Russia – Wild horses have returned to northern Siberia. So have musk oxen, hairy beasts that once shared this icy land with woolly mammoths and saber-toothed cats. Moose and reindeer are here, and may one day be joined by Canadian bison and deer.

Later, the predators will come — Siberian tigers, wolves and maybe leopards.

Russian scientist Sergey Zimov is reintroducing these animals to the land where they once roamed in millions to demonstrate his theory that filling the vast emptiness of Siberia with grass-eating animals can slow global warming.

Unlike “re-wilding” ideas in the United States (e.g. Montana), where most land is used for one thing or another, this one is along the Kolyma River (of gulag fame) in Siberia, which is about as isolated as one can get.

Isn’t this a little taste of what nature was meant to be, with the earth, sky, and sea “swarming with swarms of living creatures?” (Gen 1:20,24).

Grace and Peace

Related news: Leaking Siberian ice raises a tricky climate issue

Environmental philosophies – some preliminary thoughts

I was reading sections out of Principles of Conservation Biology (Meffe et al., I have the 2nd edition) tonight just for fun*. The first two chapters lay a philosophical foundation for conservation biology, exploring various perspectives on environmental ethics and biodiversity.

In chapter 1—What is Conservation Biology?—the authors discuss the philosophical movements that have led to conservation efforts in the United States:

  1. The Romantic-Transcendental Conservation Ethic — The 19th century proponents of this position included Ralph Waldo Emerson, Henry David Thoreau, and John Muir. Nature was viewed as a place to escape from civilization, as something to be preserved in a pristine state. For the pioneers of this movement, there was a spiritual aspect to nature, which was viewed as a work of God, though not always “God” in the Christian understanding. This ethic led eventually to the creation of national parks and wilderness areas, and the preservationist philosophy of Muir and others is carried on today in many non-profit conservation groups such as the Sierra Club.
  2. The Resource Conservation Ethic — The first key proponent of this in the United States was forester Gifford Pinchot, who approached the natural world from a utilitarian perspective. This was a very anthropocentric (man-centered) view of nature; there are resources out there for humans to use, but they must be used wisely and efficiently so they will be available for future generations. One idea that flowed out of this was the multiple-use concept, where the land must be managed for many users simultaneously, such as for grazing, logging, recreation, and watershed protection.
  3. The Evolutionary-Ecological Land Ethic — Often referred to just as the “land ethic,” this was introduced by Aldo Leopold in A Sand County Almanac in 1949. This viewpoint integrates what we have learned about the biological world in the past one hundred plus years, recognizing that natural systems are extraordinarily complex, interrelated, and dynamic. Any change we make to one part of an ecosystem can and will effect other parts of the ecosystem, sometimes in ways that are difficult to predict even with careful analysis.

What is a Christian to make of these perspectives? I see valuable lessons that can be drawn from all three, and have a few cautionary ideas as well.

The preservationists recognize that nature has inherent value beyond what is in it for human beings. From a Biblical perspective, it is good to remember that in Genesis 1:25, God declared that the creation was already “good” at the point when all was created except for the first humans. Because of this, not only do individual organisms have value (the birds of the air and the lilies of the field, Matthew 6:26-28), but so do populations, species, and entire ecosystems. Many preservationists tend towards non-Christian religious concepts such as transcendentalism and eastern mysticism, but that does not negate the observation that there are Biblical principles which are consistent with the preservationist ethic. My caution for Christians is to not confuse “creation care” with the gospel. It is good to protect animals and ecosystems, but doing so is not the good news of Christ, but part of the overall ethical package of Christianity.

The conservationists recognize that resources can be utilized by humans, but that this needs to be done in a sustainable way. The Genesis 1:28 mandate to Adam to “Be fruitful and multiply and fill the earth and rule and have dominion over it,” when understood properly should guide us to be good gardeners rather than wasteful exploiters of the creation. The creation is not ours; we are placed here as vice-regents, with God as the ultimate owner of all. My caution here is that there are voices in the Evangelical Christian community who call for “wise use” in a way that that is presented as consistent with the conservationist ethic, but whose proposals are no more than short-sighted exploitation of resources that leave nothing for future generations.

Many Christians might be frightened away from the Evolutionary-Ecological Land Ethic by the inclusion of the word evolutionary, but I think this is unnecessary, even if one rejects biological evolution as the explanation for the origin of the living world. The land ethic recognizes the extreme complexity of the living world that God has placed on this Earth. We should not be surprised that the infinite God of the universe would create a biosphere (by whatever means he chose to use) that contains intricacies within intricacies, whether at the level of cellular biochemistry or at the level of the interactions between components of entire ecosystems. This flows from the Trinitarian view of God: there is one God but he is not a simple God, and his nature is reflected in his creation (Romans 1:19-20). The caution, as the textbook authors bring out, is that one cannot leave humans out of the picture.

Of these, I am a Christian preservationist at heart, in that I marvel at the wonders that God has placed around us and see the creation as having value in itself, apart from what it can provide for us. I am thankful that there are preserved places that are readily accessible, whether they be in suburban St. Louis, or wonderlands such as Yellowstone National Park. I am also thankful for the wild places that are not as accessible to humans. As a youth, I went on several long backpacking trips through the Absaroka-Beartooth Wilderness Area in south-central Montana, which has close to one million acres of land that is closed to development of any kind. Though I spend more than 99 percent of my life outside of such places, it is comforting to know that there are places that reflect the intrinsic value with which God has endowed his creation.

I also recognize the value of the land ethic. Science is a tool that God has given us for understanding his creation, and one thing that is clear is that the living world is characterized by change and interaction. The land ethic allows us to see how the biosphere works, and how humans effect the living world. If we are to be stewards of the creation for God’s glory, for the good of the creation, and for the benefit of all mankind, then we need this scientific understanding.

I have reviewed a couple books on Christian environmental perspectives in the past. For the Beauty of the Earth by Steven Bouma-Prediger comes mostly from a Christian preservationist perspective, though he does have a good awareness of ecological relationships. I’ll have to think a bit more about where exactly Francis Schaeffer comes from in his Pollution and the Death of Man, but he certainly had a strong aesthetic streak in him, so his views are mostly compatible with the preservationist ethic.

A Christian author who comes from a conservationist perspective would be Calvin Beisner. I have not read any of his works.

I’ll hope to write about what chapter two says about the “Judeo-Christian Stewardship Ethic” later this week.

Grace and Peace

*I know, probably less than 1% of the population reads college textbooks for fun, but so be it.