*“Death is caused by swallowing small amounts of saliva over a long period of time.”* ~ George Carlin BTM
On Fri, Oct 12, 2012 at 10:19 PM, Wayne Tyson <[email protected]> wrote: > ABSQOLUTELY! > > WT > > PS: "It's no use, Professor Agassiz, it's turtles all the way down!" --A > woman who asserted that the earth rested upon the back of a giant turtle, > and made this remark when Agassiz asked ". . . upon what, then, madam, does > the turtle rest?" "Another turtle, of course," the woman kept responding. > (At least this is how I remember the story.) > > McCallum has touched upon the reason why I have suggested to the > Smithsonian Library of Life project that they accumulate data on the ranges > of organism's requirements and limitations. > > > ----- Original Message ----- From: "malcolm McCallum" < > malcolm.mccallum@HERPCONBIO.**ORG <[email protected]>> > To: <[email protected]> > Sent: Friday, October 12, 2012 8:16 PM > Subject: Re: [ECOLOG-L] correlation v. causation > > > The whole point of a correlation is that you don't really know what is >> going one with two or more variables, but you think there might be a >> relationship of some kind. That is why we say correlation doesn't >> indicate causation. >> A regression does indicate causation because we name a determinant >> variable. For example, if you take a bunch of guppies in a glass of >> water and add salt until the die, then you are testing to see how much >> salt kills guppies. You do a regression. However, if you go out in >> the wilderness and measure salt concentrations and count guppies for >> unrelated reasons, and after looking at your data you say, hey it >> looks like guppies might be getting killed by salt, you still do a >> regression because you are looking for the effect of salt on guppies, >> it sure isn't very logical even if narrowly possible that guppies are >> changing the salt concentration of the water. Now, if you are doing >> measurements on all kinds of data. YOu happen to notice that a lot of >> guppies are in ponds that also have plants. You have no idea if the >> plants are helping the guppies, if the guppies are helping the plants, >> or if some third factor is influencing both of their apperaance. SO, >> you run a correlation to see if the association you seem to observe is >> actually happening. Later, you can set up experimetns to determine >> why plants and guppies have correlated presence absence rates. In >> those following experiments you might use a regression. (this all >> assumes you have the experiment set up properly for the tests I >> mention!!!! :) >> >> Make sense? >> >> On Tue, Oct 9, 2012 at 12:56 PM, Wayne Tyson <[email protected]> wrote: >> >>> Hi y'all, >>> >>> If I remember the quote correctly, it said "Correlation is not >>> causation." >>> It did not say that it didn't imply causation. The distinction is >>> crucial, >>> eh? (It appears that my initial response to the initial question didn't >>> make >>> its way to Ecolog, possibly because I neglected to approve it or because >>> it >>> was rejected. >>> >>> WT >>> >>> PS: Correlation is not in opposition to (v.) causation. >>> >>> Let us not jump to contusions. >>> >>> ----- Original Message ----- From: "Devan McGranahan" >>> <[email protected]> >>> To: <[email protected]> >>> Sent: Tuesday, October 09, 2012 8:57 AM >>> >>> Subject: Re: [ECOLOG-L] correlation v. causation >>> >>> >>> Hi Shelley, others, >>>> >>>> Slate recently had a great article on correlation and causation with a >>>> historical perspective. >>>> >>>> My favorite line: "'No, correlation does not imply causation, but it >>>> sure as hell provides a hint." >>>> >>>> >>>> http://www.slate.com/articles/**health_and_science/science/** >>>> 2012/10/correlation_does_not_**imply_causation_how_the_** >>>> internet_fell_in_love_with_a_**stats_class_clich_.html<http://www.slate.com/articles/health_and_science/science/2012/10/correlation_does_not_imply_causation_how_the_internet_fell_in_love_with_a_stats_class_clich_.html> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> "Having nothing better to do, I set fire to the prairie." >>>> -- Francis Chadron, 1839, Fort Clark, North Dakota >>>> >>>> http://www.devanmcgranahan.**info <http://www.devanmcgranahan.info> >>>> >>>> >>>> ----- >>>> No virus found in this message. >>>> Checked by AVG - www.avg.com >>>> Version: 10.0.1427 / Virus Database: 2441/5317 - Release Date: 10/08/12 >>>> >>>> >>> >> >> >> -- >> Malcolm L. McCallum >> Department of Molecular Biology and Biochemistry >> School of Biological Sciences >> University of Missouri at Kansas City >> >> Managing Editor, >> Herpetological Conservation and Biology >> >> "Peer pressure is designed to contain anyone with a sense of drive" - >> Allan Nation >> >> 1880's: "There's lots of good fish in the sea" W.S. Gilbert >> 1990's: Many fish stocks depleted due to overfishing, habitat loss, >> and pollution. >> 2000: Marine reserves, ecosystem restoration, and pollution reduction >> MAY help restore populations. >> 2022: Soylent Green is People! >> >> The Seven Blunders of the World (Mohandas Gandhi) >> Wealth w/o work >> Pleasure w/o conscience >> Knowledge w/o character >> Commerce w/o morality >> Science w/o humanity >> Worship w/o sacrifice >> Politics w/o principle >> >> Confidentiality Notice: This e-mail message, including any >> attachments, is for the sole use of the intended recipient(s) and may >> contain confidential and privileged information. Any unauthorized >> review, use, disclosure or distribution is prohibited. If you are not >> the intended recipient, please contact the sender by reply e-mail and >> destroy all copies of the original message. >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 10.0.1427 / Virus Database: 2441/5327 - Release Date: 10/12/12 >> >>
