Antagonistic Pleiotropy

Pleiotropy is when one gene has multiple functions and is very common in development, physiology, and life history of multicellular organisms.  Antagonistic pleiotropy describes situations in evolution when an allele has function(s) that are advantageous as well as function(s) that are disadvantageous.  Two conceptually well known types of antagonistic pleiotropy are in loci thought to be responsible for aging (senescence) and in loci that are advantageous in one sex and disadvantageous in the other sex (sexually antagonistic pleiotropy).  The reasons why these genes/alleles increase to fixation (100%) in populations is that the advantage of their "good" function outweighs the disadvantage of their "bad" function.  For example, many alleles thought to be responsible for senescence are thought to have been selected for their advantages earlier in life, such as in increased juvenile fitness or increased fertility and fecundity.  Since reproduction occurs before aging, then evolution cannot "see" the disadvantages that accrue later in life from alleles that are really good to have earlier in life, so those alleles increase to fixation in populations.  Today I thought about a converse kind of potential antagonistic pleiotropy: genes that are disadvantageous (at least mildly so) early in life and turn out to be advantageous later in life (but not too late, so still before or during reproductive maturity).  I don't know what to call this yet, but of course what inspired me are the many traits of small children that are so hard to deal with but are the by-products of a developing brain that when mature yields tons of advantages later on in life.  I need to do more thinking about this concept and relate to the evolution of neoteny and parental care.  Perhaps more on this down the road...