Whether evolutionary history is mostly contingent or deterministic has been given much focus in the field of evolutionary biology. Studies addressing this issue have been conducted theoretically, based on models, and experimentally, based on microcosms. It has been argued that the shape of the adaptive landscape and mutation rate are major determinants of replicated phenotypic evolution. In the present study, to incorporate the effects of phenotypic plasticity, we constructed a model using tree-like organisms. In this model, the basic rules used to develop trees are genetically determined, but tree shape (described by the number and aspect ratio of the branches) is determined by both genetic components and plasticity. The results of the simulation show that the tree shapes become more deterministic under higher mutation rates. However, the tree shape became most contingent and diverse at the lower mutation rate. In this situation, the variances of the genetically determinant characters were low, but the variance of the tree shape is rather high, suggesting that phenotypic plasticity results in this contingency and diversity of tree shape. The present findings suggest that plasticity cannot be ignored as a factor that increases contingency and diversity of evolutionary outcomes.

#### data1

Supporting data
File name: Trial 1 ~ 18
Each file contains the results of each attempt.
Each file contains following data.
Main_result[number].dat: number represents the generation. This file shows the coordinates of the tips and tails of all branches that construct the organisms. Four lines represent one branch. The line 4n represents the coordinates of the tip of the branch, and the line 4n represents the coordinates of the tail of the branch. The line 4n+2 and 4n+3 are blank, where n is integer.
Lightamount_[number].dat: number represents the generation. This file shows the light received by each tree. Each line contains the data of the root coordinate of the tree, and the light amount received.
Typeparameter.dat: This file contains the parameters of the tree types developed in the simulation. Each line contains the data of the branching angle 1, Branching angle 2, Branch attenuation rate 1, Branch attenuation rate 2, Rotation angle, Leaf radius, Leaf absorption rate, Tendency to move, Avoid threshold, Rate of avoid reaction, and Death threshold. All the parameters are described in the method.

#### data2

Supporting data
File name: Trial 19 ~ 36
Each file contains the results of each attempt.
Each file contains following data.
Main_result[number].dat: number represents the generation. This file shows the coordinates of the tips and tails of all branches that construct the organisms. Four lines represent one branch. The line 4n represents the coordinates of the tip of the branch, and the line 4n represents the coordinates of the tail of the branch. The line 4n+2 and 4n+3 are blank, where n is integer.
Lightamount_[number].dat: number represents the generation. This file shows the light received by each tree. Each line contains the data of the root coordinate of the tree, and the light amount received.
Typeparameter.dat: This file contains the parameters of the tree types developed in the simulation. Each line contains the data of the branching angle 1, Branching angle 2, Branch attenuation rate 1, Branch attenuation rate 2, Rotation angle, Leaf radius, Leaf absorption rate, Tendency to move, Avoid threshold, Rate of avoid reaction, and Death threshold. All the parameters are described in the method.

#### data3

Supporting data
File name: Trial 37 ~ 54
Each file contains the results of each attempt.
Each file contains following data.
Main_result[number].dat: number represents the generation. This file shows the coordinates of the tips and tails of all branches that construct the organisms. Four lines represent one branch. The line 4n represents the coordinates of the tip of the branch, and the line 4n represents the coordinates of the tail of the branch. The line 4n+2 and 4n+3 are blank, where n is integer.
Lightamount_[number].dat: number represents the generation. This file shows the light received by each tree. Each line contains the data of the root coordinate of the tree, and the light amount received.
Typeparameter.dat: This file contains the parameters of the tree types developed in the simulation. Each line contains the data of the branching angle 1, Branching angle 2, Branch attenuation rate 1, Branch attenuation rate 2, Rotation angle, Leaf radius, Leaf absorption rate, Tendency to move, Avoid threshold, Rate of avoid reaction, and Death threshold. All the parameters are described in the method.