In 1971 I published a theory in which I first formulated the DNA end replication problem and
explained how it could be solved. The solution to this problem also provided an explanation
for the Hayflick Limit, which underpins the discovery of in vitro and in vivo cell senescence. I
proposed that the length of telomeric DNA, located at the ends of chromosomes consists of
repeated sequences, which play a buffer role and should diminish in dividing normal
somatic cells at each cell doubling. I also proposed that the loss of sequences containing …