.post img { border:5px solid #fbfe03; padding:2px; }

Sunday, June 5, 2011

Monday, May 30, 2011

Sunday, May 22, 2011

Species Reemergence After The Collapse



Species pairs that disappear through hybridization after human-induced changes to the environment can reemerge if the disturbance is removed, according to a new mathematical model that shows the conditions under which reemergence might happen.


By simulating environmental disturbances that reduce the ability of individuals to identify and select mates from their own species, the model explores the mechanisms that cause hybridization between closely-related species. Hybridization can lead to population decline and the loss of biodiversity. For instance, certain species of stickleback fish have collapsed into hybrid swarms as water clarity in their native lakes has changed, and certain species of tree frogs have collapsed as vegetation has been removed around their shared breeding ponds. Such hybrid swarms can replace the original species.


Triplicate Girl, Duo Damsel & The LSH © DC Comics
The reemergence of species pairs is more likely when the disturbances were strong than when they were weak, and most likely when disturbances were quickly corrected. However, even temporary bouts of hybridization often led to substantial homogenization of species pairs. This suggests that ecosystem managers may be able to refill ecological niches, but probably won't be able to resurrect lost species after species collapse.
Ref: Hybridization, species collapse, and species reemergence after disturbance to premating mechanisms of reproductive isolation. Evolution. R.T. Gilman and J.E. Behm, published online April 29.

Friday, May 20, 2011

Napoleon & Benjamin Franklin vs The Thing From Another World (1951)


Mystery In Space #3 (1951) © DC Comics
Script: Manly Wade Wellman [as Robert Starr]; Art: Bob Oksner; Inks: Bernard Sachs

Manly Wellman wrote primarily for Quality Comics, including a long run on The Spirit. His writing skills elevate a dopey premise into an engaging story obviously inspired by 1951 film The Thing From Another World ("An intellectual carrot? The mind boggles!") that would have only been released a month or so before this story was written.

The scientific team of time-travel inventor, Anne Rell, and super-botanist, Carr Davis, have a nice chemistry and I could easily see these two having been spun off into their own series ala the Inside Earth team of Cave Carson or Rip Hunter's Time Masters (hmm, maybe Anne actually invented Rip's time machine?). Anyone for a revival over there at DC?

I'd even have read more stories of the time traveling team of Napoleon and Benjamin Franklin.




CLICK TO ENLARGE












Thursday, April 28, 2011

Single Gene Mutation Shapes Cerebro!


Jimmy Olsen © DC Comics
The size and shape of the human cerebral cortex, an evolutionary marvel responsible for everything from Shakespeare's poetry to the atomic bomb, are largely influenced by mutations in a single gene.
The findings are based on a genetic analysis of in one Turkish family and two Pakistani families with offspring born with the most severe form of microcephaly. The children have brains just 10 percent of normal size. They also lacked the normal cortical architecture that is a hallmark of the human brain. This combination of factors has not been seen in other genes associated with the development of the human brain, the authors note.

The researchers found that mutations in the same gene, centrosomal NDE1, which is involved in cell division, were responsible for the deformity.

"These findings demonstrate how single molecules have influenced the expansion of the human cerebral cortex in the last five million years," Gunel said. Link
Ref: The Essential Role of Centrosomal NDE1 in Human Cerebral Cortex Neurogenesis. 2011. M. Bakircioglu, et al. American Journal of Human Genetics.

Monday, April 18, 2011

Kids Reading Comics (1951)


Well, at least one kid.
The photo is scanned from a magazine called Friends, (Ceco Publishing for Chevrolet Dealers, August 1959). There is no photo credit given.

Based on the presence of White Chief of the Pawnee Indians # 1 in the photo, I'm guessing that it was taken in 1951.

Thanks to Clive Coy for the scan!

Saturday, April 2, 2011

Born This Day: Francesco Maria Grimaldi


Gramaldi (April 2, 1618 - Dec. 28, 1663) was an Italian mathematician and physicist who studied the diffraction of light. He observed the image on a screen in a darkened room of a tiny beam of sunlight after it passed pass through a fine screen (or a slit, edge of a screen, wire, hair, fabric or bird feather). The image had iridescent fringes, and deviated from a normal geometrical shadow.


He coined the name diffraction for this change of trajectory of the light passing near opaque objects (though, more specifically, it may have been interferences with two close sources that he observed). This provided evidence for later physicists to support the wave theory of light.

With Riccioli, he investigated the object in free fall (1640-50), and found that distance of fall was proportional to the square of the time taken. link