Editing David Lack (section)

===Lack's Principle===
In 1943 Lack took an interest in clutch size after reading Moreau's manuscript sent to the ''Ibis''. Lack was then an assistant to the editor of the ''Ibis''.<ref>Anderson (2013):62.</ref> Lack postulated what is now known as Lack's Principle, which states that "the clutch size of each species of bird has been adapted by natural selection to correspond with the largest number of young for which the parents can, on average, provide enough food".<ref>Lack D (1954) The regulation of animal numbers. Clarendon Press, Oxford</ref><ref>{{cite journal |last1=Pasztor |first1=E |last2=Loeschcke |first2=V |title=The Coherence of Cole's Result and Williams' Refinement of Lack's Principle |journal=Oikos |date=November 1989 |volume=56 |issue=3 |pages=416–420 |doi=10.2307/3565627 |jstor=3565627 |bibcode=1989Oikos..56..416P |url=https://www.jstor.org/stable/3565627}}</ref>
<ref>{{cite journal |last1=Williams |first1=George C. |title=Natural Selection, the Costs of Reproduction, and a Refinement of Lack's Principle |journal=The American Naturalist |date=December 1966 |volume=100 |issue=916 |pages=687–690 |doi=10.1086/282461 |jstor=2459305 |bibcode=1966ANat..100..687W |url=https://www.jstor.org/stable/2459305}}</ref>