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.
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
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.
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