A paper in Nature disputes the significance of the KT boundary event:

I've been loving the combined ScienceBlogs feed over the past few weeks.

Along with the new io9 blog, these feeds continue to feed a longstanding love for both science and science fiction.

Take together, they provide a great mix of what is and what could be.

Today's reading brought me to to Greg Laden's blog, where he comments at length on a new paper published in Nature that disputes importance of the KT Boundary Event in mammalian evolution. (See the abstract for The delayed rise of present-day mammals for more; full access requires registration or a trip to the (gasp) library.)

As Laden says:

The KT boundary event is the moment in time when a ca. 10 km. diameter object going very fast hit the earth in the vicinity of the modern Yucatan, causing the extinction of the dinosaurs (and almost everything else larger than a microwave). It has been suggested that this event resulted in (allowed for) the subsequent diversification of the mammals, presumably because the earlier extinction event opened up previously filled niches, into which the mammals evolved, and possibly because of dramatic climate change that occurred with this event.

One of the reasons that this study is important is that it seems to falsify this long-standing hypothesis.

This paper is thoughtfully discussed on Pharyngula and Sandwalk, and I recommend that you have a look at those sites.

I suspect some of my more geologically-inclined friends will find this interesting as well. I'm glad to see that our understanding of evolutionary history continues to, well, evolve, based upon new research.

Eric Schulman's "Wiki history of the universe in 200 words or less"

Brilliant. From the Science Creative Quarterly:

Quantum fluctuation. Inflation. Expansion. Strong nuclear interaction. Particle-antiparticle annihilation. Deuterium and helium production. Density perturbations. Recombination. Blackbody radiation. Local contraction. Cluster formation. Reionization? Violent relaxation. Virialization. Biased galaxy formation? Turbulent fragmentation. Contraction. Ionization. Compression. Opaque hydrogen. Massive star formation. Deuterium ignition. Hydrogen fusion. Hydrogen depletion. Core contraction. Envelope expansion. Helium fusion. Carbon, oxygen, and silicon fusion. Iron production. Implosion. Supernova explosion. Metals injection. Star formation. Supernova explosions. Star formation. Condensation. Planetesimal accretion. Planetary differentiation. Crust solidification. Volatile gas expulsion. Water condensation. Water dissociation. Ozone production. Ultraviolet absorption. Photosynthetic unicellular organisms. Oxidation. Mutation. Natural selection and evolution. Respiration. Cell differentiation. Sexual reproduction. Fossilization. Land exploration. Dinosaur extinction. Mammal expansion. Glaciation. Homo sapiens manifestation. Animal domestication. Food surplus production. Civilization! Innovation. Exploration. Religion. Warring nations. Empire creation and destruction. Exploration. Colonization. Taxation without representation. Revolution. Constitution. Election. Expansion. Industrialization. Rebellion. Emancipation Proclamation. Invention. Mass production. Urbanization. Immigration. World conflagration. League of Nations. Suffrage extension. Depression. World conflagration. Fission explosions. United Nations. Space exploration. Assassinations. Lunar excursions. Resignation. Computerization. World Trade Organization. Terrorism. Internet expansion. Reunification. Dissolution. World-Wide Web creation. Composition. Extrapolation?

The Helix Nebula

[In this image provided by NASA shows a newly expanded image of the Helix nebula Friday Aug. 24, 2007 lending a festive touch to the fourth anniversary of the launch of NASA's Spitzer Space Telescope. This spectacular object, a dying star unraveling into space, is a favorite of amateur and professional astronomers alike. Spitzer has mapped the expansive outer structure of the six-light-year-wide nebula, and probed the inner region around the central dead star to reveal what appears to be a planetary system that survived the star's chaotic death throes. Spitzer launched from Cape Canaveral, Fla., on August 25, 2003. (AP Photo/NASA-JPL)]