Variation 39 Calculus of variations 36 GENETICS : A Periodical Record Of Investigations Bearing On Heredity And Variation 19 Calculus of variation-- Analysis-- Mathematics 17 Genetics 13 GENETICS: A PERIODICAL RECORD OF INVESTIGATIONS BEARING ON HEREDITY AND VARIATION 12 English language 9 Genetic variation 9 Human evolution 8 Mathematical optimization 8 Control theory 7 Evolution 7 Genetic Variation 7 Human genetics 7 Probability 7 Variation (Biology) 7 Variational principles 7 chromosomes 7 cytogenetics 7 Differential equations 6 Mathematical analysis 6 Sociolinguistics 6 Frequency Distribution 5 Human molecular genetics 5 Mathematics 5 Plant Breeding and Genetics 5 Plants 5 variation 5 variation genetics 5 Somaclonal variation 4