Ancient rules for Bilaterian development


Assuming that none of my readers are perfectly spherical, you all possess notable asymmetries—your top half is different from your bottom half, and your front or ventral half is different from you back or dorsal half. You left and right halves are probably superficially somewhat similar, but internally your organs are arranged in lopsided ways. Even so, the asymmetries are relatively specific: you aren’t quite like that Volvox to the right, a ball of cells with specializations scattered randomly within. People predictably have heads on top, eyes in front, arms and legs in useful locations. This is a key feature of development, one so familiar that we take it for granted.

I’d go so far as to suggest that one of the most important events in our evolutionary history was the basic one of taking a symmetrical ball of cells and imposing on it a coordinate system, creating positional information that allowed cells to have specific identities in particular places in the embryo. When the first multicellular colony of identical cells set aside a particular patch of cells to carry out a particular function, say putting one small subset in charge of reproduction, that asymmetry became an anchor point for establishing polarity. If cells could then determine how far away they were from that primitive gonad, evolution could start shaping function by position—maybe cells far away from the gonad could be dedicated to feeding, cells in between to transport, etc., and a specialized multicellular organism could emerge. Those patterns are determined by interactions between genes, and we can try to unravel the evolutionary history of asymmetry with comparative studies of regulatory molecules in early development.

[Read more…]

Delaware theocrats vs. the Dobrich family

The NY Times has a decent summary of the Dobrich case—the families in the Indian River school district of Delaware who are suing to end the state sponsorship of sectarian religion that is running amuck there. Most of the residents there don’t seem to get it—I wish people would stop calling this a school prayer issue, because it plays right into their hands. It isn’t and never has been about restricting people’s ability to say prayers or practice whatever consensual superstitious nonsense in which they want to indulge. It’s about preventing the power of state authorities being used to compel people to join in unwanted religious practices.

It’s probably impossible to explain that the problem is about refusing to give a particular sect a monopoly on religion in an area, or about denying secular authority to the pastor of some random church, when the citizens are as oblivious as the thick-witted bible-thumper who made the comment below:

A homemaker active in her children’s schools, Mrs. Dobrich said she had asked the board to develop policies that would leave no one feeling excluded because of faith. People booed and rattled signs that read “Jesus Saves,” she recalled. Her son had written a short statement, but he felt so intimidated that his sister read it for him. In his statement, Alex, who was 11 then, said: “I feel bad when kids in my class call me ‘Jew boy.’ I do not want to move away from the house I have lived in forever.”

Later, another speaker turned to Mrs. Dobrich and said, according to several witnesses, “If you want people to stop calling him ‘Jew boy,’ you tell him to give his heart to Jesus.”

I don’t want to ever hear anyone calling atheists “arrogant” anymore, either. We’ve got nothing on this kind of smug, pious con artist.

“Because Jesus Christ is my Lord and Savior, I will speak out for him,” said the Rev. Jerry Fike of Mount Olivet Brethren Church, who gave the prayer at Samantha’s graduation. “The Bible encourages that.” Mr. Fike continued: “Ultimately, he is the one I have to please. If doing that places me at odds with the law of the land, I still have to follow him.”

Hmmm. My militant atheist philosophy encourages me to spit on the wingtips of puffed-up sanctimonious preachers, and my bladder encourages me to piss on the foundations of the cheap gathering halls they use to fleece their flocks. It’s useful to know that our whims supersede not just civility, but the laws of the land.

The Big Bang for Dummies

I’m not a cosmologist and I don’t even pretend to be one on the internet, but as an evolutionist I hear far more about the Big Bang from creationists than I should…and it’s everything from the Big Bang never happened to the Big Bang disproves evolution, and often both opinions are held by the same person, who will often also tell me both that the Cambrian is proof of sudden creation and that the earth is less than 10,000 years old (consistency is not a quality valued by most creationists). It’s therefore rather handy to have a summary of misconceptions about the Big Bang all in one place.

I could use a sign like that…if we can change “dog” to “cat”


Isn’t that a sweet little old lady? I guess the sign offended a few people, though, and they turned her in to the police.

Insisting that the sign was simply a lark, Mrs Grove said yesterday that she had never received any complaints about it. But police ordered her to take it down and her details were taken. Once the officers left she hung the sign back up.

I like that last bit—what a simple no-nonsense response to bureaucratic BS.

She said: “it’s been there for more than 30 years and all the people who live nearby are used to it. I couldn’t believe it. I’ve never had any complaints with any religion. The sign is just a lark that’s been there for a long time.

I don’t know. I’m looking at that obviously vicious little puppy and wondering how many Jehovah’s Witnesses he had eaten that day.

At least the British seem relatively civil about the whole thing. Symbols seem to inflame a whole ‘nother level of insanity in this country.

(hat tip: Richard Dawkins. Yeah, that Richard Dawkins.)