International Scholarly Research Notices

Research Article

IBP′: A New Index to Estimate Biogeographical Peculiarity

Table 2

Hypothesized scenario for the IBP. Several cases have been hypothesized in the OEUs from 1a to 6, that is, from the highest to the lowest number of endemic species. To get consistent values of peculiarity the IBP must be weighed, so that the value of each chorological spectrum is gradually decreasing from 1a to 6. If the IBP is computed following [3] it fluctuates from 1a to 6 with inconsistent values (e.g., 2a versus 2b), while the IBP′ gradually decreases from 1a to 6 following the gradient of decreasing peculiarity.


Rank ord.	Cases chor.cat.	1a		1b		2a		2b		3a		3b		4a		4b		5a		5b		6
Rank ord.	Cases chor.cat.	%	Σ	%	Σ	%	Σ	%	Σ	%	Σ	%	Σ	%	Σ	%	Σ	%	Σ	%	Σ	%	Σ

6	I	1	1	0.10	0.10	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
5	II	0	1	0	0.1	1	1	0.01	0.01	0	0	0	0	0	0	0	0	0	0	0	0	0	0
4	IIIm	0	1	0	0.1	0	1	0	0.01	1	1	0.01	0.01	0	0	0	0	0	0	0	0	0	0
3	III	0	1	0	0.1	0	1	0	0.01	0	1	0	0.01	1	1	0.01	0.01	0	0	0	0	0	0
2	IV	0	1	0	0.1	0	1	0	0.01	0	1	0	0.01	0	1	0	0.01	1	1	0.01	0.01	0	0
1	V	0	1	0.9	1	0	1	0.99	1	0	1	0.99	1	0	1	0.99	1	0	1	0.99	1	1	1

	IBP	1		0.100		0.800		0.008		0.600		0.006		0.4		0.004		0.200		0.002		0.000
	wIBP	7		6.1		5.8		5.01		4.6		4.0		3.4		3.0		2.2		2.0		1.0
	IBP′	1		0.87		0.83		0.72		0.66		0.57		0.49		0.43		0.31		0.29		0.14