2 posts tagged with evolution by blahblahblah.
Displaying 1 through 2 of 2.
You have certainly seen a Tree of Life at some point (not the movie; the diagram of the evolution of species). Originally conceived of by Lamarck (though there is some interesting debate on this), it was Darwin himself who popularized the concept, first in his notebook, and next as the only image in The Origin of the Species. Though they have inspired beautiful illustrations, and a large and fascinating web project to map the tree, trees of life remain problematic since taxonomy can be complicated. One truly stunning way of redrawing the tree is the Hillis Plot, which maps 3,000 species by genetic similarity. You can print out the amazing illustration here, but, even though the Plot only contains 0.18% of named species, it needs to be 1.5 meters square to be legible. The Hillis Plot has been appearing in art, notably (and meta-rifficly) this one carved into an English oak, and, of course, tattoos.
The number of communicating alien civilizations = R* x fp x ne x fl x fi x fc x L. The formula is the Drake Equation, and modern estimates range from several thousand to none but us. You can solve it yourself. What is your estimate of the number of alien civilizations out there?