World Population 
is called the equipartition of energy.) You can see the logic 
of this by taking the opposite extreme: if you have equal 
mutation rates but only one male to the whole population of 
females, then you are not getting maximum variability from 
the mutation rate. Presumably what nature is trying to do is to 
produce high variability. 
Parkes: Iwas hoping that somebody would produce a valid 
reason for the existence of us males. 
Haldane: J should like a formal proof of Dr. Bronowski’s 
theorem. Such theorems sometimes turn out to involve some 
remarkable assumptions. 
MacKay: This notion of efficiency is apt to be troublesome 
in a biological context unless we ask explicitly, efficient with 
respect to what? Thus when Professor Parkes commented on 
the inefficiency of maintaining a million tons of redundant male 
bio-mass, he presumably meant “efficiency with respect to 
human meat production”’. Once made explicit, this thrusts us 
back to Sir Julian’s question—what are humans for? 
Bronowski: ‘The definition in my theorem is, efficient with 
respect to the exploitation of the potential variability which 
mutation creates. 
Pirie: Ilagree that this excess of men isn’t very alarming and 
variations in the laws of a country could possibly compensate 
for any chaos that might be introduced. But if it should become 
alarming we might direct Dr. Pincus back to some of his earlier 
studies on parthenogenesis (virgin birth) where you get female 
offspring only. If we could get parthenogenesis going in man we 
would be able to produce any extra number of women who are 
required to even out the ratio. Now, having said that flippantly, 
I am going to ask more seriously, what is the present status of 
parthenogenesis in mammals? 
Pincus: The present status is not very good; it is a very 
inefficient process by the methods we have used. Dr. Chang 
in our laboratories has increased the rate of parthenogenesis 
in treated rabbit ova by a large percentage, but the eggs only 
develop to a very early stage; the yield of mature animals is 
negligible. 
115 
