Table 1. Numbers and mean lengths for proteins and pseudogenes in four eukaryotes.

Organism	Number of proteins	Number of pseudogenesa	Number of processed pseudogenes	Mean length of proteinb	Mean length of matching protein for pseudogenes
Humanc	927	384 (2.4)	189	317 (±43)	342
Nematode worm	20732	1100 (18.9)	104	435 (±15)	450
Budding yeast	6340	221 (28.7)	0	467 (±29)	424d
Fruit fly	14332	110 (130.3)	34e	500 (±50)	808f

^aThe proportion of proteins to pseudogenes is given in brackets.

^bStandard deviation of the sample mean is given in brackets.

^cThese data are for chromosomes 21 and 22 only (7).

^dThe difference between mean lengths of yeast proteins in general and those that are closest matches to pseudogenes is marginally significant (P < 0.06) using normal statistics.

^eThis value is for pseudogenes (i) that are of substantial length (>70% the length of the closest matching organismal protein) and have no introns (where a matching protein does have introns) or (ii) that have some evidence of polyadenylation. See Materials and Methods for more detail. These procedures are described in (7).

^fThe difference between mean lengths of fruit fly proteins in general and those that are closest matches to pseudogenes is very significant (P < 0.0001) using normal statistics. Removing the outlying matchers of seven fragments whose lengths exceed 3000 amino acids, reduces the mean to 610 residues (P < 0.02).