What is the major take-home point of the study? Why is this
What assumptions do the authors make, based on the blog post? Dothe authors deal with these assumptions?
His first winter at the University of Mississippi Field Station,Matt Pintar was wading through some ponds where he noticed a largenumber of egg masses. Clear jelly surrounded most of these eggmasses, but a whitish jelly encased some of them. These egg masseswere produced by the spotted salamander, Abystoma maculatum, which immediately made Pintar wonder whythese differences exist within this species. Biologists use theterm “polymorphism†to describe a situation like this, in which twoor more forms (poly = multiple, morph = form) exist within apopulation.
Could it simply be random chance that there were two egg massmorphs? Or was one morph better than the other in gettingfertilized by the appropriate sperm, or in keeping the eggstogether? Alternatively, perhaps one morph was better at providingnutrients or protecting against predators. The puzzle is that ifone morph was superior to the other, then that morph would befavored by natural selection, should outcompete the other, andultimately cause the second morph to go extinct. So why did bothmorphs persist in this population of spotted salamanders?
Pintar and his colleague Willliam Resetarits Jr. thought itmost likely that the polymorphism was a chance event that providedno benefit to the salamanders. But they did consider thealternative that one morph might be better in some conditions,while the other morph was better in other conditions. Surveys doneabout 25 years ago suggested that the polymorphism might beconnected to differences in water chemistry, so Pintar andResetarits decided to explore this possible link with a combinationof observations of natural ponds and field experiments onartificial ponds.
