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Morrison Q&A #3

Responding to Public Questions and Misconceptions

David Morrison

June 18, 2010

David Morrison answers more common questions

Question: I read that the solar storm is coming up in 2013, and it will be a big one, too. I understand that a solar storm doesn't kill us, but it says that certain technologies will be knocked out from the solar storm. Is this going to happen?

Answer: The article you refer to notes that “the Sun is about to get a lot more active, which could have ill effects on Earth. So to prepare, top sun scientists met Tuesday to discuss the best ways to protect Earth's satellites and other vital systems from the coming solar storms. The Sun is waking up from a deep slumber, and in the next few years we expect to see much higher levels of solar activity, said Richard Fisher, head of NASA's Heliophysics Division”. Note that there is nothing here that says “the solar storm is coming”. What it does say is that solar activity is increasing toward the expected solar maximum in 2013. The Sun has an 11-year activity cycle. There is more solar activity (or solar storms) in the years around the peak. This is not about one solar storm, and in any case solar storms are not predictable far in advance. For an analogy, think about hurricanes. Recently there was news about the annual Caribbean hurricane season, which is about to begin. We know there is a hurricane season, and we know there will be several hurricanes. We do not know when they will come, or how big they will be, or where they will hit land. People who operate satellites should (and will) take precautions to protect their systems against solar storms, but that should not worry you or me. The bottom line for the Sun is that if you weren’t hurt by the solar maxima in 1990, or 2001, you you are not likely be hurt by the one in 2013.

Question: Is is it possible to make DNA as we wish?

Answer: Some of the most important current issues in biology concern our ability to manipulate genetic information. Until recently, the discussions have concerned genetic engineering, the modification or insertion of one or more genes in an existing organism to achieve new capabilities, such as adding a disease-resistant gene to a crop. Often this means taking a gene from one organism and introducing it in the genome of another organism. This kind of genetic manipulation has already yielded many successes, with genetically modified crops now accounting for a substantial fraction of world agriculture. The new frontier is in genetic synthesis or synthetic biology -- the design and construction of new biological functions and systems not found in nature. The goal is to have a library of genes from which we can select parts to obtain a new, viable genome that allows us to make a new life-form. The synthesized genome is then inserted into a living cell, where it can (if properly constructed) take over the functions of the cell, and ultimately pass on the new genetic structure to subsequent generations. Recently Craig Venter achieved the first step in this process, constructing a new genome out of parts of other organisms and inserting it successfully in a microbial cell. He calls this new cell Mycoplasma laboratorium. An analogy might be the construction of a building, in which the builders don't make the construction materials (bricks, cut wood, steel rebar, cement etc.) but can combine them in a variety of ways to construct different buildings. This kind of work represents the frontiers of biology, and it raises multiple ethical issues as well as exciting scientific challenges.

Question: You say there is no evidence of aliens visiting earth... what about when humans suddenly appeared out of nowhere 250,000 years ago? Could that not be alien life arriving on earth?

Answer: Humans did not appear suddenly 250,000 years ago. We have a long and complex family history revealed by both the fossil record and genetic comparisons with other animals. See “timeline of human evolution” in Wikipedia for a summary . The great apes (Hominidae) appeared on Earth 15 million years ago, and about 6 million years ago the human lineage separated from that of the chimpanzees. By 2 million years ago our ancestor, Homo erectus, was living in Africa, giving rise to the first true humans (Homo sapiens) around 200,000 years ago. But even if we did not have this fossil record, we know that humans are genetically similar to other animals (with 98% identical genes with the chimpanzees). Genetic analysis is the clearest way to demonstrate the common evolutionary heritage of life on Earth. There is no way that humans could have come from elsewhere. We are a part of the history of life on this planet, not some weird transplant from beyond.

David Morrison

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David Morrison is a long-time NASA senior scientist and Committee for Skeptical Inquiry fellow. He now divides his time between the SETI Institute and the NASA Lunar Science Institute. He hosts the "Ask an Astrobiologist" column at NASA's website.