Talk:Cope's rule

Removal of content
The end section is unclear and unreferenced; I am inclined to remove it unless anyone can justify its inclusion, preferably by improving the clarity of the prose. The Van Valkenborough quotation could also use linking in better with the text. Can anyone help? Smith609  Talk  19:24, 30 May 2008 (UTC)


 * Does what I've just done help? I've hacked the "Validity" section from separate randomly organised sentences into a series of paragraphs that tries to present a coherent "story" about the Rule's validity.  The Van Valkenborough quote now sits within the portion describing evidence for the Rule.  Anyway, today's the first time I've heard of Cope's Rule, so I may have actually made things worse.  I hope not.  Cheers, --P LUMBAGO  07:47, 20 August 2008 (UTC)

Misleading information in "Capping Growth" section?
The section entitled "Capping Growth" includes this sentence: "For example, carnivores over 21 kg must prey on organisms larger, not smaller, than themselves."

This statement is sourced and is only being used as an example. However, it also appears to be misleading. Polar bears are an example of a carnivorous species over 21kg that preys almost exclusively on smaller species. (There is evidence of polar bears attacking and killing small whales, but this is extremely rare.)

Moving outside the order Carnivora (is that what is meant anyway?) there are many other carnivorous species over 21kg that prey exclusively on smaller species. Examples would be dolphins, porpoises and seals.

Can this statement be corrected? Or a different example used? Demiurge1000 (talk) 05:08, 28 July 2010 (UTC)


 * You raise a good point, but there may be a simple fix: qualifying the statement and limiting it to terrestrial predators (which are all the reference discusses). WolfmanSF (talk) 07:30, 28 July 2010 (UTC)


 * Thanks, that looks perfect. I didn't want to edit it myself without discussion first, as my familiarity with the topic is rather limited. Demiurge1000 (talk) 03:26, 1 August 2010 (UTC)


 * However, the polar bear example still remains. And grizzlies, kodiaks, and other large predators such as tigers that more often than not outweigh their most common prey. Now granted, some I have mentioned are omnivores, but so are most species we generally think of as carnivores. I suggest removing the sentence entirely. Garth of the Forest (talk) 03:24, 27 September 2012 (UTC)
 * Current wording works, I guess. Garth of the Forest (talk) 03:34, 27 September 2012 (UTC)

Origin of Cope's rule
Please note that I have read both books that are usually cited as the source of Cope's rule, and I have found no statement that justifies attributing this rule to Cope. Of course, Cope may have written something to that effect, but apparently not in the publications that are credited for this. The paper that is cited to justify this rule on the page is not even from Cope, so this does not alleviate my concern. Charles Depéret, whom the French credit equally for this rule (known to French scientists as the Cope-Depéret rule), did write something very clear on this topic, and I think that this should be incorporated into the page. And note that other Europeans, like Germanic-speaking people, tend to attribute this rule more to Depéret than to Cope. Michel Laurin (talk) 14:12, 6 August 2013 (UTC)
 * Cope was a prolific author; it is possible that there is no single publication of his that represents the obvious origin of this rule. It's unlikely the attribution of the idea to Cope arose out of a vacuum. WolfmanSF (talk) 22:22, 6 August 2013 (UTC)
 * After looking into this further, it's looking like it did arise from something close to a vacuum (see Polly, 1998); I've modified the intro accordingly. WolfmanSF (talk) 06:29, 7 August 2013 (UTC)

Thanks WolfmanSF (talk). This paper, which I had not seen, confirmed my doubts. I just corrected the page numbers because the Science table of contents is wrong; I have the pdf file. Apparently, Science gives p. 47 as the page on which several correspondence papers appear, but that is wrong; that section spans several pages. Michel Laurin (talk) 08:40, 8 August 2013 (UTC)