Dream of Science!

I dreamed there was a news paper article with the headline, "The Nutroavailabitizer!"

Below the headline, there was a picture of a long skinny fish with a big weird bumpy appendage, almost as massive as the main fish, sticking up from its tail. The article was quoting a scientist who had concluded that the function of this big appendage was to take nutrients in the water in the stream where it lived, and convert them to a form that would be easier for the trees around the stream to use. In the dream, Iris asked me what I thought of that, and I said that it didn't make very much sense from an evolutionary perspective, because the fish would be putting enormous energy and resources into building and operating the filter thing, and it would make the fish much less streamlined, and in the end the only benefit the fish gets is healthier trees around the stream. I argued that if there was a mutation for not having that appendage, the mutant fish would still get the benefit of the healthier trees, because of the other fish still having the filters, but would not have to support the costs of having a filter itself. Likewise, if there were no fish with that filter, and one had a mutation that caused it, or an earlier version of it, only it would bear the costs but all would get the benefits, so it would be at a disadvantage again. Iris asked why I thought the fish did have it, and then my cellphone rang with a 7AM automated sales call.

Global Amphibian Declines call for frog costumes.

There are few, if any, taxa losing species diversity as quickly and thoroughly as the amphibians.

From amphibiaweb.org:

"Amphibians, a unique group of vertebrates containing over 6,200 known species, are threatened worldwide. A recent assessment of the entire group (globalamphibians.org) found that nearly one-third (32%) of the world’s amphibian species are threatened, representing 1,856 species. Amphibians have existed on earth for over 300 million years, yet in just the last two decades there have been an alarming number of extinctions, nearly 168 species are believed to have gone extinct and at least 2,469 (43%) more have populations that are declining. This indicates that the number of extinct and threatened species will probably continue to rise (Stuart et al. 2004)."

And this is almost surely an overly optimistic view. The thousands of species for which we have no data are not considered threatened, and an unknown number of others, likely in the hundreds, has gone extinct without ever being discovered.

Amphibian lineages that have existed for tens of millions of years are ending shockingly quickly. The factors that are killing off these ancient groups are all the works of humanity: pesticides, industrial pollutants, introduced species and diseases, habitat destruction and alteration and rapid climate change. There is no reasonable doubt but that we have driven the rate of amphibian extinction to several thousand times its natural rate. We could barely kill them off more quickly if we tried. Genocide is not too strong a term.

Amphibians are widely seen as indicator species. Healthy ecosystems have healthy amphibians. Indications are poor.

So to help raise (the currently abysmally low) awareness of the scope of amphibian declines, Iris and I have decided to walk Bay to Breakers wearing homemade from costumes. And we hope to organize a group of friends and colleagues to walk with us, similarly garbed. A costume recognizable as an amphibian, or even a shirt with amphibian pictures on it. Perhaps we will hand out informational pamphlets to people who ask what we are about. If you are interested in joining us, please email me.

"Science" "Journalism"

Even taking into account how poor the state of science journalism is in this country, and what a sorry rag the San Fransisco Chronicle is, this piece on the danger posed to San Francisco by invasive pythons is well below the curve.
To summarize, there is an introduced population of Burmese pythons in the Everglades, 3100 miles away. A USGS lab used an off the shelf climate model to predict where in the US Burmese Pythons could deal with the climate, and San Francisco (along with pretty much the southern half of the US) showed up as one potential habitat.

The idiot who wrote the article then follows this train of thought to show that pythons will be eating pedestrians on Market Street by 2020:
•One python showed up at Lake Okeechobee, 100 miles north of the Everglades, and in the same direction it would travel if its single-minded goal was to reach Fisherman's Wharf.
•Pythons can travel up to 20 miles a month, and the road to SF is 3000 miles, so it will be here in 150 months, or about 12 years.
•Pythons eat mammals.
•"Human beings - like rodents, beavers and deer - are mammals, government scientists confirmed."
•Giant snakes falling from office buildings and eating you.
•QED

The sad thing is, reading the article, I am not sure if he is joking, but I am sure there are some people who will think this is a real threat.

Germ-line chimerism and paternal care in marmosets (Callithrix kuhlii)

Reference:
Ross, C., J. French, and G. Ortí. 2007. Germ Line Chimerism and Paternal Care in Marmosets (Callithrix kuhlii). Proc. Natl. Acad. Sci. USA, 104 (15): 6278–6282.


Abstract:
The formation of viable genetic chimeras in mammals through the transfer of cells between siblings in utero is rare. Using microsatellite DNA markers, we show here that chimerism in marmoset (Callithrix kuhlii) twins is not limited to blood-derived hematopoietic tissues as was previously described. All somatic tissue types sampled were found to be chimeric. Notably, chimerism was demonstrated to be present in germ-line tissues, an event never before documented as naturally occurring in a primate. In fact, we found that chimeric marmosets often transmit sibling alleles acquired in utero to their own offspring. Thus, an individual that contributes gametes to an offspring is not necessarily the genetic parent of that offspring. The presence of somatic and germ-line chimerism may have influenced the evolution of the extensive paternal and alloparental care system of this taxon. Although the exact mechanisms of sociobiological change associated with chimerism have not been fully explored, we show here that chimerism alters relatedness between twins and may alter the perceived relatedness between family members, thus influencing the allocation of parental care. Consistent with this prediction, we found a significant correlation between paternal care effort and the presence of epithelial chimerism, with males carrying chimeric infants more often than nonchimeric infants. Therefore, we propose that the presence of placental chorionic fusion and the exchange of cell lines between embryos may represent a unique adaptation affecting the evolution of cooperative care in this group of primates.

Translation: According to the seminar I went to today, what this all means is that Marmosets and their relatives almost always produce fraternal twins, and the embryos grow in close proximity, with out the usual membranes separating them. The two developing embryos can actually have blood vessels in common, meaning that blood born cells can move from one embryo to the other. And stay there. And develop. So when the little monkeys are born and grow up, they can be riddled with cells that are genetically part of their sibling. This is what we call a chimera, when one individual has cells that are of different genetic lineages.
So then one of the chimeric monkeys mates. But some of his germ line cells (the ones that make sperm) are genetically his brother. So he's doing the mating, but the young could be genetically his nephews. Weird, I know. And one outcome of all this is that marmosets put a lot more energy into taking care of their nieces and nephews than would otherwise be expected. Ain't evolution weird and wonderful.

Cartoon explanation: