Talk:Chronospecies

message: Did you really mean to write another example is the recent genetic reproduction of the pathogen responsible for the 1918 world-wide influenza pandemic?  Surely this concept only applies to sexually reproducing organisms?---CH  (talk) 02:16, 7 November 2005 (UTC)
thread_title: Another example: 1918 flu virus?

message: Some sources would help here, there being under a thousand ghits for this term. Just zis Guy you know? 23:14, 20 March 2006 (UTC)
thread_title:  Sources 

message: Would the different species humans evolved through qualify as chronospecies?  Raccoon Fox • Talk • Stalk 18:54, 20 August 2006 (UTC)
replies: text: Well, they could. Nobody can prove, though, that this or that particular fossil is the direct and immediate ancestor. So, for purely logical reasons, taxonomists (including those working with hominid fossils) prefer to speak in terms of sister-group relationships even if they suspect that this particular fossil and modern humans may belong to the same chronospecies. Alexei Kouprianov 09:45, 10 January 2007 (UTC)
thread_title:  [[Human Evolution]]? 

message: How do the differences between remnants of a Shih tzu and a Great Dane relate to this article? —The preceding unsigned comment was added by 84.230.246.101 (talk) 07:26, 10 January 2007 (UTC)
replies: text: No, they can be better interpreted in terms of sister group relationships (with some reticulate evolution somewhat obscuring the branching pattern). Unless you speak of the developments within the breed (as long as they are considered to be of the same breed). See, here population biology (which is about self-reproducing biological entities) meets philosophy of taxonomy (which is, in part, about counting species the same or not)... Alexei Kouprianov 11:08, 10 January 2007 (UTC)
thread_title:  Dog breeds 

message: I have some problems with this article, and thought I'd throw my thoughts out before doing any edits.
1) The definition of chronospecies, "A chronospecies is a species which changes physically, morphologically, genetically, and/or behaviorally over time on an evolutionary scale such that the originating species and the species it becomes could not be classified as the same species had they existed at the same point in time.", is IMO correct but incomplete. A chronospecies is a named species-level taxon which is _not separate from ancestral or descendant forms by a speciation event_ (branching of the lineage), but is separated from other species solely by time (hence "chrono-").
 
From a phylogenetic point of view, a chronospecies is not a separate species at all, it is one single species changing over time, although different names have arbitrarily been assigned to fossils of the lineage at different points in time (due to the incompleteness of the fossil record, or as the article puts it, "chronospecies are usually recognized because two species in the same lineage are named by palaeontologists without knowledge of any intermediate organisms."). 
Ie, chronospecies are _grades_.
The discussion about "unchanged" species simply does not make sense to me - if a fossil is morphologically indistinguishable from another they are classified in the same species, regardless of the interval between the forms. It is not so that if two fossils are more distant in time than X they're separate species.
The discussion of "phyletic gradualism" & punk eq is confused. The fundamental assumption of punctuated equilibrium is that species can not undergo change except during speciation (branching of the lineage), and hence any change is interpreted as necessarily associated with a speciation event, whether a sister taxon is ever found or not. 
"Phyletic gradualism", on the other hand, is *not* a statement about the rate of change, the difference is simply that it allows change also when the lineage isn't branching, ie phyletic change. 
In other words, under punc eq lineages CAN NOT change without splitting, and the concept of chronospecies does not make sense in a punc eq framework.
213.114.237.122 15:56, 27 August 2007 (UTC)
thread_title:  Partially inaccurate 

message: The previous section points out some of the problems in this article, which seem
to still exist in the current version. Other issues also exist.
* The article lead inaccurately mentions behavioral changes as a factor in identifying chronospecies, but it actually can only use evidence from the fossil record. So, the recognition of these groups basically relies on the morphology or (rarely) the genetics.
* The article incorrectly indicates that the term paleospecies is always a contrasting term. Actually, it just indicates a species known only through the fossil record, so any given example may or may not be part of a chronospecies sequence.
* Since it uses an incomplete concept of paleospecies, most of the current second paragraph is either wrong or so tangled it contradicts itself. In particular, the statement that "a morphologically unchanged fossil record... would obviously represent the remains of several species" is completely unfounded. A period of stasis can indicate anything: samples from some currently living species still overlap with known fossil forms. The reference to Howard (1947) is also contradictory. The linked article proposes a discussion for the consequences of species classification due to the existence of gradual changes in the fossil record. In fact, it is most likely suggesting the concept of a chronospecies, not the supposedly contrasting paleospecies it is said to discuss.
Basically, I've rewritten everything except the links to other articles.
StephenMacmanus (talk) 04:44, 27 October 2010 (UTC)
thread_title:  Article cleanup