Re: Why human have no heat period but most primates have ?

Who says human females do not come into heat.  ‘Heat’ is that period of time 
when the female is most receptive to mating.  It also happens to coincide 
with the period during which the female is most likely to get pregnant.  In 
most animals, not just primates, the female comes into heat only at a time 
of year that assures that the resulting birth will occur at the beginning of 
a season that is most favorable for survival of the newborn.  In general, 
the males do not come into heat.  They are willing and usually anxious to 
mate at any time.  This is generally true for human males also.  However, we 
have adapted our local micro-environment so that the local seasons and 
weather patterns no longer need to have any influence on the human female 
estrous cycle.  Survival of human infants is independent of the season or 
weather outside the home.  Therefore we lost the evolutionary pressure to 
synchronize the estrous cycle with a season.  We are left with the question 
of whether there is a time frame during the human estrous cycle during which 
the woman is most receptive to mating.  I’m not sure the answer to this is 
‘no’ as you suggest.  I think we are too influenced in our thinking by the 
large body of popular literature that says humans are generally promiscuous 
and always interested in sex.  We are also by-and-large a chauvinistic 
species with little reason to ask our mates ‘how receptive’ are you tonight.  
Remember, the males are always willing and ready.  There is a small bit of 
anecdotal evidence that suggests that some, maybe most, women are in fact 
‘more receptive’ during that time of their estrous cycle when they are most 
likely to get pregnant.  If this is true, then human females do come into 
heat.  If we assume the anecdotes are false, we are left to answer why.  It 
is easier to assume the anecdotes are true than to say "I don’t know".