next message in archive
no next message in thread
previous message in archive
previous message in thread
Index of Subjects
PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px"= Well said, Dave ! By coincidence, I've just come across this post on ID Frontiers, where the paper is also under discussion. The author is also located at Cornell but is the lead researcher who has divided Red Crossbills into about 10 races/sub-species/ possible species (please stay tuned, in other words). His work on Red Crossbills has been well-respected. Here is his post: "Kudos to the authors! As their work still supports though, there are still plenty of obvious "looking" Hoary Redpolls. Also, the researchers were quick to note, "they still only sampled less than 1% of the total genome." As most things in science are, this is an "evolving" story. Matt Young Ithaca, NY" Rick Whitman ===================== On 4/5/15, David & Alison Webster <dwebster@glinx.com> wrote: > Dear All, Apr 5, 2015 > I failed to make clear, in this previous post, that I agreed with Lance > that birders should continue to record splits, in this case Hoary & Common > Redpoll, even if the powers that be conclude (for the time being) that they > are one species. Records of observably different forms can readily be > pooled, if need be, but pooled observations can not be subsequently parsed. > My grasp of current Genetics is not especially firm but I fail to see > how the.study (posted by Nancy R., below) shows these forms to be > essentially identical. They apparently examined only 1% of the genome. > Even if the DNA of these1% samples are nearly identical it does not > follow that the remaining 99% of the genome will have equally similar DNA. > And the DNA code is comparable to the contents of a library; some retained > for possible future need, some sequentially borrowed and read during > development of the embryo and much that is not currently relevant. > And RNA of the two forms, the blueprints in current use, was more > distinct. No doubt the two forms readily interbreed but recording variation > over time and location might eventually be informative. > Who could have forseen that the large collection of birds' eggs at the > London Museum would one day provide the conclusive proof which linked use of > DDT with thinning of egg shells ? > Yt, Dave Webster, Kentville > ----- Original Message ----- > From: David & Alison Webster > To: naturens@chebucto.ns.ca > Sent: Tuesday, March 31, 2015 8:24 PM > Subject: Re: [NatureNS] Hoary and Common Redpolls one species? > > > Hi Lance & All, Mar 31, 2015 > The recurrent lumping & splitting of many species clusters is perhaps an > indirect consequence of the 'type specimen' concept. The notion being that, > if you just do it carefully enough, all species can be defined in ways which > are distinct from other similar species. This is just a form of looking in > the dark closet for the black cat that is not there; and finding it. > > As G.G. Simpson, Prof. of Vertebrate Paleontology at the Museum of > Comparative Zoology of Harvard Univ., observed (1967, Biology and the Public > Good) "...organisms cannot be truthfully or usefully considered in terms of > types." > > One should be prepared to accept that within some broadly defined > species there may be many different branches which are not quite distinct > and which, given the opportunity, can produce fertile offspring. > > Yt, Dave Webster, Kentville > > > > ----- Original Message ----- > From: Laviolette, Lance (EXP) > To: naturens@chebucto.ns.ca > Sent: Tuesday, March 31, 2015 6:08 PM > Subject: RE: [NatureNS] Hoary and Common Redpolls one species? > > > Hi everyone, > > > > Ultimately the question of "what is a species" currently comes down to the > determination of how much DNA difference is enough. The paper doesn't say > that Hoary Redpolls and Common redpolls have identical DNA, it says that the > DNA is extremely similar. Ultimately the American Ornithologists Union, > which is the body which makes the final decision in North America, will > decide if the DNA is similar enough to lump the two or not. > > > > There is certainly no harm in continuing to report the two 'forms' of > redpolls regardless of the species status. The Ipswich form of the Savannah > Sparrow is an example of this that is near and dear to the heart of Nova > Scotia birders. Who knows, in the distant future new methods and/or decision > makers may declare that the difference between Common and Hoary Redpolls is > in fact not as similar as this paper has concluded. If that time arrives > then people will wish they recorded them separately. > > > > All the best, > > > > Lance > > > > Lance Laviolette > > Glen Robertson, Ontario > > > > > > > > From: naturens-owner@chebucto.ns.ca [mailto:naturens-owner@chebucto.ns.ca] > On Behalf Of N Robinson > Sent: Tuesday, March 31, 2015 2:21 PM > To: naturens@chebucto.ns.ca > Subject: EXTERNAL: [NatureNS] Hoary and common redpolls one species? > > > > This just in: > > > http://blog.allaboutbirds.org/2015/03/30/from-many-one-how-many-species-of-redpolls-are-there/ > > Nancy
next message in archive
no next message in thread
previous message in archive
previous message in thread
Index of Subjects