In a nutshell. Plants follow the Fibonacci sequence (1,1,2,3,5,8,13) in their phyllotaxis, which is the arrangement of leaves, branches, or petals around a stem.
How many fingers a leaf has, how many it has is a general representation of how well the plant is performing cell division overall, a 2 finger leaf indicates sub optimal growing conditions that restricts genetical expression through tough environment. Genetics are not a fixed, deterministic blueprint, but rather a complex, dynamic, and probabilistic interplay between inherited DNA (nature) and environmental influences (nurture). While genetics provide the foundational framework, environmental factors play a critical role in determining how, when, and if genes are expressed. Good luck.