Tag Archives: evolutionary

Dandelion Sex, Or The Lack Thereof

Dandelion (From Wikipedia)

Dandelion (From Wikipedia)

I’ve just finished reading Frogs, Flies, & Dandelions: the making of species by biologist Menno Schilthuizen –an engaging and informative book on species formation. Here’s a little taste of what I learned; it illustrates that genetics isn’t perfect, and evolution is beautifully adaptive.

Historically, the common dandelion, that ubiquitous and irritating weed found in gardens and fields throughout North America and Europe, has been a puzzle to botanists. For a long time, no one was sure how many species existed. In the 1700’s, Carolus Linnaeus said only one; in the 20th century, Scandinavian botanists claimed more than two-thousands existed. But with DNA testing, came the answer. Many dandelions are, in fact, clones. In place of normal sexual reproduction with two sets of chromosomes being divided into sex cells, the ovules and pollen, some dandelions reproduce by parthenogenesis, or virgin birth, because at one point in their history they mutated into having three sets of chromosomes, a number which is sexually indivisible. The mutant dandelions instead produce unfertilized –but still viable– seeds, each with a triple set of chromosomes –in other words, a clone.

What’s most illuminating is that the same mutation has popped up several times. So there are several strains with triple chromosomes, all sexually isolated from one another because they can only reproduce by cloning themselves. But it gets better; the clones still produce pollen, except it is completely sterile. Only in the light of evolution does this sordid asexual tale make sense. Why waste the time and energy producing “irregular pollen” if it’s never going to be used? Perhaps god takes a sadistic pleasure in irritating people’s allergies. Or he’s invested heavily in big pharmaceuticals. If so, I hope he had Bernie Madoff sitting on his nest egg.

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Filed under Biology, Evolution, Science

More Lies Supporting Expelled: The Movie

Pseudo-Science

Pseudo-Science

Ben Stein is putting his smirk and whiny voice to ads for the DVD release of Expelled: The Movie, No Intelligence Allowed. Christmas is just around the corner and a rotten lump of pseudo-scientific coal makes such a great stocking stuffer for the kids. In the ads, Mr. Stein claims Expelled is the #1 documentary of 2008. I think not. Let’s check the stats. Expelled grossed about 7.7 million and opened in 1052 theaters, while Bill Mahr’s documentary Religulous grossed 10.6 million and only opened in 502 theaters. If Mr. Stein is alluding to the reviews of Expelled making it #1, then he is wrong on that point, too. Most reviews were resoundingly negative. For example, The New York TImes said,

Mixing physical apples and metaphysical oranges at every turn “Expelled” is an unprincipled propaganda piece that insults believers and nonbelievers alike. In its fudging, eliding and refusal to define terms, the movie proves that the only expulsion here is of reason itself.

Finally, if you go to the Expelled website you can crash their ironic poll asking, “Do you think Darwin’s theories are outdated?” If Darwin is over-the-hill, then creationism is fossilized. I made a funny.

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Filed under Intelligent Design