The ApoE4 allele was the primordial human isoform present during roughly 96% of hominid evolution, whereas chimpanzees lack ApoE4.
"and that's actually the primordial one. It's the one that was present for about 96% of hominid evolution. If you look at a chimp, for example, it does not have ApoE4, but the hominids do." (said at 0:14:55)
The speaker combines two claims: that ApoE4 is the ancestral (primordial) hominid isoform present throughout most of human evolutionary history, and that chimpanzees lack ApoE4. While genetic analysis confirms that ApoE4 (with arginine residues at positions 112 and 158) is indeed the ancestral primate state from which ApoE3 and ApoE2 subsequently derived roughly 200,000 to 300,000 years ago, chimpanzees and other non-human primates actually possess the ApoE4-equivalent isoform (Arg112/Arg158). Chimpanzees do not lack ApoE4; rather, their APOE sequence is monomorphic and closely related to human epsilon-4.
- contradicts: Apolipoprotein E variation at the sequence haplotype level: implications for the origin an… (American journal of human genetics 2000)
"Sequence analysis of the chimpanzee APOE gene showed that it was most closely related to human epsilon4-type haplotypes, differing from the human consensus sequence at 67 synonymous (54 substitutions and 13 indels) and 9 nonsynonymous fixed positions. The evolutionary history of allelic divergence within humans was inferred from the pattern of haplotype relationships. This analysis suggests that haplotypes defining the epsilon3 and epsilon2 alleles are derived from the ancestral epsilon4s and that the epsilon3 group of haplotypes have increased in frequency, relative to epsilon4s, in the past 200,000 years." (abstract, results, passage verified)
pubmedfull study (doi) - contradicts: Arginine residues at codons 112 and 158 in the apolipoprotein E gene correspond to the anc… (Atherosclerosis 1995)
"The only differences between these isoforms result from cysteine-arginine interchanges at codons 112 and 158. There is considerable disagreement in the literature concerning the identity of the ancestral allele. In order to resolve this, 24 chimpanzees and individuals from a number of other primate species were analysed. All were similar to apo E4. This suggests that apo E4 is the ancestral allele and that apo E2 and apo E3 arose after the split of the human and chimpanzee lineages." (abstract, results, passage verified)
pubmedfull study (doi)