Earlier this month, we looked at some man-made extensions to the bacterial genetic code. If that story got you worried about Dr. Frankenstein, you're going to love last week's announcement. Harvard biologists believe that within two years they will be able to create a woolly mammoth-African elephant hybrid embryo. Bringing back the mammoth is part of a larger program of "de-extinction" to explore the possibility of bringing back various extinct species, at least some of which we humans are responsible for eliminating. … [Read more...] about Science in Review: Pleistocene Park