Test Subjects
What specific animal was the study conducted on?
Green Anoles
In which states did the study take place?
Texas and Oklahoma
How many genomic regions did the authors find that differentiated in the surviving Southern population?
14 genomic regions.
Will the subjects after the winter storm have a higher or lower fitness? Why or why not?
The subjects will have a higher fitness because the survivors will have a lower critical temperature, allowing them to have a better resistance to extreme winter storms in the future
Which body part of the organism did the researchers study?
The liver
How many sample sites were there?
Five
To what example were the researchers attempting to compare the southernmost subject population?
They were attempting to observe how close the southernmost population's genes shifted to the northernmost population's.
Do winter storms decrease genetic diversity between populations?
Yes! The southernmost population became more alike to the northernmost population!
Why did the researchers decide to use the transcriptomes of a specific body part in this animal?
The organ contains Chromosome II, which codes for a multitude of cold sensitive proteins that potentially play vital roles in nervous system functioning
What caused the winter storms in 2013-2014?
A weakened low-pressure zone caused the polar vortex to move over the United States.
How did the scientists know that the cold resistance wasn't due to acclimation?
The scientists took four subjects from the northernmost and southernmost study sites and used a common-garden acclimation before the winter storm at both 20 degrees and 30 degrees Celsius. They also did the same acclimation test on three of the test sites (one being the southernmost site) after the winter storm.
Which types of evolutionary forces does the winter storm impose on the test subjects?
Genetic drift (in the form of bottle neck) and directional selection towards cold tolerant phenotypes.
What outlier peak were the scientists most interested in, or why were they interested in it?
The fixation index (FST outlier) peak due to its transcription of five key genes in nervous system regulation.
What was special about the winter storm in 2013-2014?
It brought much colder temperatures than had been observed in the last 15 years.
What did the scientists do to ensure that the effects of the winter storms were long term?
They re-sampled the subjects in Brownsville, the southernmost site in July to test their minimum critical temperature. They remained on par with their previous test.
Why could this study been seen as counter to a typical notion in evolution?
It concludes that big weather events can create large shifts in in genes, meaning that their evolution occurs over a very short period of time rather than a long period of time.
Critical Thermal Minimum
Why did the scientists choose sample sites at different latitudes?
The subjects in the sites at different latitudes were adapted to different temperatures.
Did the longitudinal location of the sites change much? If so, why? If not, why not?
The longitudinal location shifted a minor amount, most likely due to site restrictions for the study. The researchers would probably want to keep the longitudinal variable consistent, as they wanted to test differences in the variation of the latitudinal locations.
What animal species study inspired the researchers to conduct this study?
A study on the effects of a winter storm on house sparrows and how it affected the suvivors' body sizes.