June 2004 Archives

Evolution 2004

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The Evolution Conference 2004 begins in two days. This year it is being held at Colorado State University in Fort Collins, CO. This yearly conference is probably the biggest in the field of evolutionary biology. The Evolution Conference is jointly sponsored by the Society for the Study of Evolution, the Society of Systematic Biologists, and The American Society of Naturalists.

This year’s schedule includes symposia on estimating clade ages, adaptation during ecological invasions, biological diversity, teaching evolution, sexual dimorphism, and evolution of plant phenotypes.

I will be attending, but not presenting anything. I will be gone till July 2, and probably have intermittent internet access during the time. Next year’s conference is in Alaska, and I hope to present some of my research there.

My wife was out of town last week when she rode her bike across Georgia. She says that she is now adventured out. This is a picture of her on the last day in Savannah.

After complaining about something stupid in my local paper, I find something cool.

(AP) Mutation Found in ‘Muscle Man’ Toddler

This is a AP report on a discovery reported recently in the NEJM. Apparently, a German boy was born with a pair of genetic mutations that block myostatin production. Myostatin is a negative control on muscle growth. Thus this child who is not yet five has adult level strength. Since I haven’t had time to grab the actual report, I assume that the actual mutations are loss of function mutation. Instead of “blocking” the action of myostatin as report indications, these mutations probably cause myostatin production to be broken. But, like I said I haven’t read the paper.

Some interesting sections from the AP report.

Researchers would not disclose the German boy's identity but said he was born to a somewhat muscular mother, a 24-year-old former professional sprinter. Her brother and three other close male relatives all were unusually strong, with one of them a construction worker able to unload heavy curbstones by hand.

In the mother, one copy of the gene is mutated and the other is normal; the boy has two mutated copies. One almost definitely came from his father, but no information about him has been disclosed. The mutation is very rare in people.

This seems to indicate that the concentration of myostatin an important part of its activity. An immediate impact on human evolution is to potentially explain the difference in strength between humans and our relatives. One obvious hypothesis is that chimps produce less myostatin than humans, thus causing them to have higher muscle mass. I also would not be surprised if testosterone somehow represses myostatin, which would explain how the hormone promotes muscle mass.

The actual paper is:

References

I think I found one of the dumbest letters to the editor I have ever seen.

Gay marriage may not reduce certain health threats

Garret Cook

J.D. Haynie’s assessment (June 15 letter) that monogamous homosexual unions could help prevent the spread of STDs is based on much theory and little fact.

The following two paragraphs come from the Family Research Council’s Web site:

The journal AIDS reported that men involved in relationships engaged in anal intercourse and oral-anal intercourse with greater frequency than those without a steady partner. Anal intercourse has been linked to a host of bacterial and parasitical sexually transmitted diseases, including AIDS. (15. A.P.M. Coxon et al., “Sex Role Separation in Diaries of Homosexual Men,” AIDS, July 1993, pp. 877-882.)

The exclusivity of the relationship did not diminish the incidence of unhealthy sexual acts, which are commonplace among homosexuals. An English study published in the same issue of the journal AIDS concurred, finding that most “unsafe” sex acts among homosexuals occur in steady relationships (16. G. J. Hart et al., “Risk Behavior, Anti-HIV and Anti-Hepatitis B Core Prevalence in Clinic and Non-clinic Samples of Gay Men in England, 1991-1992,” AIDS, July 1993, pp. 863-869, cited in “Homosexual Marriage: The Next Demand,” Position Analysis paper by Colorado for Family Values, May 1994.)

For more well documented information, see this informative report: http://www.frc.org/get.cfm?i=IS01B1#edn16

Garret Cook Watkinsville

His source is the Family Research Council, an organization not known for its scientific accuracy. Now, does anybody care to spot the logical flaw in the letter? It should be obvious to most of you who can manage to spell your own name correctly.

Ah, hell, I can’t resist. The logical flaw is that the rates of disease are the same in exclusive relationships and non-exclusive relationships. We of course know that this is not true. People with more sexual partners will have a higher incidence of social diseases given equivalent sexual practices. If we encourage people to enter into exclusive sexual relationships early in life then the spread of social diseases will slow down. If I only have sex with one person in life, then I have much lower chances of catching a sexually transmitted disease than someone who has fifty relationships. How much buttsex I get doesn’t affect this fact. Do these people even know what a geometric distribution is?

But facts like that do not stop people afraid of two men having buttsex. Now two women having buttsex, that is another video.

Aquatic Sloths

Carl Zimmer has an interesting entry on the aquatic sloths of Peru. It is very cool. I didn’t know such creatures ever existed.

Speaking of sloths, my own university has a cool giant sloth on display in the lobby of the science library. I remember seeing it as cub scout in elementry school.

Prehistoric sloth gets new home at University

Press release, University of Georgia, April 12, 1973

Athens, Ga. – The skeleton of a giant North American sloth that roamed coastal Georgia 14,000 years ago has been assembled at the University of Georgia and will be formally dedicated April 14 by Gov. Jimmy Carter, who helped finance the project.

Measuring about 13 feet in length and weighing between 2,500 and 3,000 pounds, the skeleton is the first of a prehistoric animal ever put together in Georgia and only the fourth North American ground sloth known to have been mounted anywhere.

The bones, discovered in 1970 during the construction of Interstate Highway 95 near Brunswick, were excavated by college students directed by Dr. Michael Voorhies, associate professor of geology at the University. One of the students, Albert Brantley, an undergraduate in geology at the time, was chosen to reconstruct and mount the skeleton. He has been at the task for three years.

Carter’s interest in the project began when Brantley asked him for financial assistance. The governor promised to match any funds Brantley raised elsewhere.

With help from Albert Jones, assistant to University president Fred Davidson, Brantley received $2,000 from the university’s Alumni Foundation, which Carter matched. Later, both the foundation and the governor gave an additional $600.

The skeleton is on display in the Boyd Graduate Studies Research Center on the campus. Carter will dedicate it with a brief ceremony at 6:15pm. Davidson will introduce the governor.

When it lived during the late ice age, the adult giant sloth weighed about 3 tons and reached a height of about nine feet on all fours and about 20 feet it stood upright on its back legs. It probably had long, coarse reddish-brown hair and foot-long irretractable claws that forced it to walk on the sides of its hands.

The animal ate roots, twigs and tree leaves and was probably docile and slow-witted, Brantley said. The North American variety lived in the southeastern and central United States and a South American species lived in Central America and southwestern South America.

About 350 bones from three giant sloths were found at the Brunswick site but many were duplicates or were unusable and Brantley did not have all 208 bones necessary for one complete skeleton. So he had to make about 45 per cent of the mounted skeleton’s brownish-gray bones from plaster of paris or fiberglas. Despite this, the skeleton is by far the most complete ever found, he said.

Two other giant North American sloth skeletons are on display at the Smithsonian Institution and one skeleton – found in Georgia in the last century – is at the University of Edinburgh in Scotland, Brantley said.

Bones of several other prehistoric animals were found with the sloth bones, but Brantley said there is no doubt the creature he has reconstructed is a giant sloth. “Nothing ever had teeth like this,” he said of the animal’s inch-thick teeth, each of which is almost split crosswise by a deep crevice.

The animal probably died when it got stuck in salt marsh mud, and Brantley simulated a marsh to reconstruct the death scene. The skeleton’s two back feet and one front hand are invisible in the mud while one hand grasps for freedom.

Brantley, 25, graduated from the University of Georgia in 1970. In preparation for the mounting task, he studied at the Royal Ontario Museum, which has several South American ground sloth skeletons from which Brantley was able to make measurements and rubber molds for pieces missing from the Georgia sloth.

Photo by Georgia Harper

Letter Published

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My letter was published today. So far, no hate calls. Good thing I’m going away for the weekend.

Supreme Court gives religious equality a temporary setback

I am disappointed, but not surprised by the U.S. Supreme Court decision on Michael Newdow’s challenge to the 1954 Pledge of Allegiance. By dismissing the case on a technicality instead of making a tough and unpopular decision, the justices dodged the issue. Their decision only means the struggle for religious equality will continue.

I am sure pledge supporters will be crowing “Victory!” in the public square, but supporters must realize it is not a victory, merely a delay. The pledge is still constitutionally unsound, and because the Supreme Court did not rule on the case’s merits, another party can still challenge the pledge. I hope another concerned parent or guardian is out there willing to step up and take the baton from Newdow. If they do, then the case against the pledge can stand on its own merits.

Ultimately, Newdow helped raise awareness about this religiously divisive issue and laid the groundwork for further progress. For that, I thank him. Maybe one day the pledge will return to its pre-McCarthy state, neutral to the existence of gods and truly inclusive of all Americans as “one nation, indivisible.”

The funny thing is that I’ve written enough letters to the paper that they no longer check my identity. This is the third letter in a row that I’ve had published without knowing about it before hand. They used to call me and tell me that they were publishing my letters. No more.

Savannah Ho!

I’m off to Savannah for the weekend to pick up my wife, who is ridding her bike across the state.

KwickCode Test

I’m working on an update to kwickcode. I will be using this entry to play around.

Tangled Bank #5

Tangled Bank #5 is up, over at Jason South’s place. Maybe one of these weeks when I get back to blogging biology I’ll have something to submit again to TB.

Mozilla Firefox 0.9 Out

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Firefox 0.9 has been released. I urge everyone of you to go out and install a copy.

http://www.mozilla.org/products/firefox/

Panda Metamorphosis

Go check out The Panda’s Thumb where I’ve made some slight changes to the layout.

My first paper has finally been published in Genetics: Asmussen et al. (2004). It is based on work I started when I was an undergrad.

Abstract:

Selection in which fitnesses vary with the changing genetic composition of the population may facilitate the maintenance of genetic diversity in a wide range of organisms. Here, a detailed theoretical investigation is made of a frequency-dependent selection model, in which fitnesses are based on pairwise interactions between the two phenotypes at a diploid, diallelic, autosomal locus with complete dominance. The allele frequency dynamics are fully delimited analytically, along with all possible shapes of the mean fitness function in terms of where it increases or decreases as a function of the current allele frequency in the population. These results in turn allow possibly the first complete characterization of the dynamical behavior by the mean fitness through time under frequency-dependent selection. Here the mean fitness (i) monotonically increases, (ii) monotonically decreases, (iii) initially increases and then decreases, or (iv) initially decreases and then increases as equilibrium is approached. We analytically derive the exact initial and fitness conditions that produce each dynamic and how often each arises. Computer simulations with random initial conditions and fitnesses reveal that the potential decline in mean fitness is not negligible; on average a net decrease occurs 20% of the time and reduces the mean fitness by >17%.

I’ll probably blog more on this in a few days.

Renovations

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As you can see, I’ve made some changes to my layout. Comments are appreciated.

Plagiarism

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This didn’t make the tangled bank because it delt more with education than biology, but I decided that I liked it enough to blog it with tangled bank #4.

Radagast, who teaches biology at a community college, has been busy these last few weeks dealing with students who plagiarized in his class. One corrupt student even plagiarised after having been caught once before.

Tangled Bank #4

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This is the fourth installment of the Tangled Bank, a “carnival of the vanities” focusing on biology. We have eight entries this week, covering cavies to Spartina.

Jason South of Borneo Chela is up in two weeks to host the next tangled bank.

Evomath 3

Evomath 3: Genetic Drift and Coalescence, Briefly is available on the Panda’s Thumb.

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