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Page 76 · DO #4666 · 231_Rogers_Bx2FF27_r
- Collection
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David James Rogers (1918–2007) papers
- Item/Folder
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Taximetrics Course - Student Reports, 1966–1968
- Digital Object
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DO #4666,
page 76
- Collection-level dates
- 1948–1977
Page transcription
page 15
(Student) Are you suggesting that the basic problem so far in taxonomy is that it is primarily qualitative in nature and not quantitative. That is you say a plant is pubescence, and when you are going through your key you can find the word pubescence but it doesn't really give you any indications in a quanti- tative sense as to what pubescence means with respect to the specimen you got have/. Is that what you are saying? (Dave) That's right. We could take, for the purposes of classification, I always keep these sorts of things;in mind, that this, make this statement before you say anything else. For the purposes of classification, how much is gained, for example, when you take flower colors. Now you can make analysis of the pigments and you can make a rather precise analysis to give you the exact concentration of a pigment. But suppose we want to classify plants, we look at ;the plant, we look at its flowers it has a mixture of colors available on different plants that you have, one is white, one is blue, one is red. How ;much more is gained by establishing the exact concentration of these pigments in there for the purposes of classification than merely to say, "this plant is blue". That gives you a xixxxifractional xationxstatementxrightxthexxx classificatory statement right there. This, of course, does imxxx lead you into difficulty, obviously. When xmm do you stop calling it blue? You see this is the sort of thing, you have to make some sort of a definition of what you mean by blue. You should, yes.
(Student) Well, then is seems to me the problem involves either we don't have, either you have, either in our classification system we can't express the character the plant has because it doesn't have it, or it has it to a degree which is not satisfactory with words alone. (Dave) Well, in these cases we will switch over and use wwh whatever is available to us. In other words a piece of information is only as good as you can make it. I'm not going to say that we can't, that we must define everything as a qualitative. This is wrong.
