At certain evolutionary junctures, two or more mutations participating in the 
build-up of a new complex function may be required to become available 
simultaneously in the same individuals. How could this happen in higher 
organisms whose populations are small compared to those of microbes, and in 
which chances of combined nearly simultaneous highly specific favorable 
mutations are correspondingly low? The question can in principle be answered for 
regulatory evolution, one of the basic processes of evolutionary change. A 
combined resetting of transcription rates in several genes could occur in the 
same individual. It is proposed that, in eukaryotes, changes in epigenetic 
trends and epigenetically transforming encounters between alternative chromatin 
structures could arise frequently enough so as to render probable particular 
conjunctions of changed transcription rates. Such conjunctions could involve 
mutational changes with low specificity requirements in gene-associated regions 
of non-protein-coding sequences. The effects of such mutations, notably when 
they determine the use of histone variants and covalent modifications of 
histones, can be among those that migrate along chromatin. Changes in chromatin 
structure are often cellularly inheritable over at least a limited number of 
generations of cells, and of individuals when the germ line is involved. SINEs 
and LINEs, which have been considered "junk DNA", are among the repeat sequences 
that would appear liable to have teleregulatory effects on the function of a 
nearby promoter, through changes in their numbers and distribution. There may 
also be present preexisting unstably inheritable epigenetic trends leading to 
cellular variegation, trends endemic in a cell population based on DNA sequences 
previously established in the neighborhood. Either way, epigenetically 
conditioned teleregulatory trends may display only limited penetrance. The 
imposition at a distance of new chromatin structures with regulatory impact can 
occur in cis as well as in trans, and is examined as intrachromosomally 
spreading teleregulation and interchromosomal "gene kissing". The chances for 
two or more particular epigenetically determined regulatory trends to occur 
together in a cell are increased thanks to the proposed low specificity 
requirements for most of the pertinent sequence changes in intergenic and 
intronic DNA or in the distribution of middle repetitive sequences that have 
teleregulatory impact. Inheritable epigenetic changes ("epimutations") with 
effects at a distance would then perdure over the number of generations required 
for "assimilation" of the several regulatory novelties through the occurrence 
and selection, gene by gene, of specific classical mutations. These mutations 
would have effects similar to the epigenetic effects, yet would provide 
stability and penetrance. The described epigenetic/genetic partnership may well 
at times have opened the way toward certain complex new functions. Thus, the 
presence of "junk DNA", through co-determining the (higher or lower) order and 
the variants of chromatin structure with regulatory effects at a distance, might 
make an important contribution to the evolution of complex organisms.