Developmental Genes Example - Paperwhites (geobiology)
Channel: sumnerd
Date: 2021-02-09

I happened across an example of variations in morphology that are related to developmental genes in a bundle of flowers in my yard. These paperwhites usually have a single flower on a secondary stem off the main stem. However, one of the secondary stems is thicker and has several flowers on the end of it. This is due to a difference in when genes were expressed as the cells started to differentiate to form the stem. The "wrong" timing for gene expression was passed from cell to cell as they divided, leading to a significantly different morphology.


If this difference is related to a chemical change inside the cells, it could not be passed on to future flowers through seeds. If it was related to a gene mutation and the flowers produced seeds, it might be passed on.


Paperwhites are in the Narcissus plant "genus", which also includes daffodils. People have selectively bred wild versions of these flowers to get many different shapes for the petals and cups. The mutability of the flower shape is related to variations in developmental genes that allow new morphologies to emerge in a relatively low number of generations.