Biology Reference
In-Depth Information
P. denticulata vs S. gouldingi
-
P. denticulata vs S. elongatus
P. denticulata vs S. gouldingi
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P. denticulata vs S. altuvei
P. denticulata vs S. gouldingi
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P. denticulata vs S. manueli
P. denticulata vs S. gouldingi
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P. denticulata vs S. spilopleura
P. denticulata vs S. gouldingi
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P. denticulata vs P. piraya
FIGURE 13.8
Comparisons among vectors describing the difference between
P. denticulata
and
S. gouldingi
,
and the vector describing the difference between
P. denticulata
and each of the other six species shown in
Figure 13.7. Each frame shows the contrast between the two vectors: where the squares of the grid are square, the
two vectors are the same; where the grid shows large differences, the difference between that species and
P. denti-
culata
does not resemble the difference between
P. denticulata
and
S. gouldingi.
having a homologous character). The literature on coding is large; interested readers can
find general critiques of coding methods in several papers (e.g. Farris, 1990; Thiele, 1993;
Gift and Stevens, 1997; Swiderski et al., 1998).
Any favored method can be applied to a variable that represents a character. In the spe-
cial case where PC1 is a reasonable proxy of the character “body depth”, the favored
method can be applied to scores on PC1. It is not so easy to make decisions about charac-
ters that are combinations of several variables because it is not easy to examine the
