About that story about customizing vaginal odors…

There’s an ugly turn. The story about a company creating probiotics to make vaginas smell like peaches is wrong, that’s not what the company was trying to do; instead, the “biotech entrepreneurs” who presented it as their own were lying, did not understand the project, and completely mangled the purpose. According to the actual founder of the company,

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The two faces of JE Brandenburg

Brandenburg is a physicist who submitted a paper to the 42nd Lunar and Planetary Science Conference a few years ago. It’s way outside my area of expertise, but it postulated an interesting scenario from the ratios of rare isotopes in the atmosphere of Mars: that there was evidence of a natural nuclear reactor, like Oklo on Earth, that had exploded over 180 million years ago. He makes a good case, at least to this biologist’s eyes, and it seems reasonable.

Natural Nuclear Reactors formed and operated on Earth, there is no reason this could not have happened on Mars. Conditions on Mars: lack of plate tectonics, and nearness to the asteroid belt, may have favored such occurrences in larger size and duration than on Earth. Changes in groundwater distribution, due to either climate change of loss of geothermal heat, may have triggered this event. The occurrence of such a large natural reactor may explain some puzzling aspects of Mars data, such as the superabundance of K and Th on the surface and the large inventory of radiogenic isotopes in the Mars atmosphere.

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A specular conundrum

Every year in my intro biology course, I try to do one discussion of bioethics. One lecture is not much, but this is a course where we try to introduce students to the history and philosophy of science, and I think it’s an important issue, so I try to squeeze in a little bit. So we spend one day talking about eugenics and the Tuskegee syphilis study, and I have them read Gould’s Carrie Buck’s Daughter, and I try to provoke them into arguing with me, or at least questioning a few default assumptions.

This semester, though, I’m going to have them read something with some subtler concerns. I’m going to ask them to read about the invention of the modern speculum. It was surprisingly problematic.

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When did insects evolve?

Just consult the chart.

Dated phylogenetic tree of insect relationships. The tree was inferred through a maximum-likelihood analysis of 413,459 amino acid sites divided into 479 metapartitions. Branch lengths were optimized and node ages estimated from 1,050,000 trees sampled from trees separately generated for 105 partitions that included all taxa. All nodes up to orders are labeled with numbers (gray circles). Colored circles indicate bootstrap support (left key). The time line at the bottom of the tree relates the geological origin of insect clades to major geological and biological events. CONDYLO, Condylognatha; PAL, Palaeoptera.

Dated phylogenetic tree of insect relationships. The tree was inferred through a maximum-likelihood analysis of 413,459 amino acid sites divided into 479 metapartitions. Branch lengths were optimized and node ages estimated from 1,050,000 trees sampled from trees separately generated for 105 partitions that included all taxa. All nodes up to orders are labeled with numbers (gray circles). Colored circles indicate bootstrap support (left key). The time line at the bottom of the tree relates the geological origin of insect clades to major geological and biological events. CONDYLO, Condylognatha; PAL, Palaeoptera.

Be sure to click on the image to see it at a better resolution!

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