De novo protein-coding gene origination is increasingly recognized as an 
important evolutionary mechanism. However, there remains a large amount of 
uncertainty regarding the frequency of these events and the mechanisms and speed 
of gene establishment. Here, we describe a rigorous search for cases of de novo 
gene origination in the great apes. We analyzed annotated proteomes as well as 
full genomic DNA and transcriptional and translational evidence. It is notable 
that results vary between database updates due to the fluctuating annotation of 
these genes. Nonetheless we identified 35 de novo genes: 16 human-specific; 5 
human and chimpanzee specific; and 14 that originated prior to the divergence of 
human, chimpanzee, and gorilla and are found in all three genomes. The 
taxonomically restricted distribution of these genes cannot be explained by loss 
in other lineages. Each gene is supported by an open reading frame-creating 
mutation that occurred within the primate lineage, and which is not polymorphic 
in any species. Similarly to previous studies we find that the de novo genes 
identified are short and frequently located near pre-existing genes. Also, they 
may be associated with Alu elements and prior transcription and RNA-splicing at 
the locus. Additionally, we report the first case of apparent independent 
lineage sorting of a de novo gene. The gene is present in human and gorilla, 
whereas chimpanzee has the ancestral noncoding sequence. This indicates a long 
period of polymorphism prior to fixation and thus supports a model where de novo 
genes may, at least initially, have a neutral effect on fitness.