[1][2][3][4] The plant kingdom has undergone multiple events of polyploidization followed by diploidization in both ancient and recent lineages.
[5] The mechanisms of diploidization are poorly understood but patterns of chromosomal loss and evolution of novel genes are observed in the process.
There have been rare events in which genes that ensure proper chromosome pairing have evolved shortly after polyploidization.
It has been hypothesized that dosage balance may play a key role in shaping the evolutionary fates of duplicated genes.
The main goals of diploidization are: (1) To ensure proper gene dosage; and (2) to maintain stable cellular division processes.
In other words, diploidization is a long ongoing process that is shaped by both intrinsic and evolutionary drives.
[8] Normally, homologous chromosomes pair up in bivalents during meiosis and separate into different daughter cells.
The duplicated copies of a gene are commonly non-essential to the plant's ability to maintain normal growth and development.