what is a. QUASI-SPECIES. By Ye Dan U062281A USC3002 Picturing the World through Mathematics. Definition. Quasi-: widely-used prefix to indicate “almost”, “seemingly”, “nearly” etc . Species: ?. Biological: A class of individual characterized by a certain phenotypic behavior .
By Ye Dan U062281A
USC3002 Picturing the World through Mathematics
Biological: A class of individual characterized by a certain phenotypic behavior.
Chemical: An ensemble of equal, identical molecules.
complicated and loosely defined
ie. a QUASI-SPECIES
molecules have different replication rates depending on their sequence (the faster, the fitter)
offspring sequence differ from its parent in certain positions by ‘point mutation’
Rate of growth of one variant dependent on not only itself, but also all other variants
In long run, no fixation of the fastest growing sequence. The population will reach an equilibrium which will contain a whole ensemble of mutants with different replication rates – quasi-species.
Hij is the Hamming distance between variant i and j (no. of bases in which the two strains differ)
the ratio converges to
A condition limiting the maximum length of the RNA sequence!