What types of changes in the regulation of development can lead to evolutionarily significant morphological changes?
A) Changes in when developmental genes are expressed.
B) Changes in where developmental genes are expressed.
C) Changes in development are not evolutionarily significant.
D) Both A and B are evolutionarily significant.

Question

Quizplus · Accepted Answer

Both changes in when developmental genes are expressed and where they are expressed can lead to significant morphological changes during evolution. Alterations in the timing of gene expression can result in changes in the duration and rate of development, potentially leading to new or modified morphological features. Changes in spatial expression patterns can result in the emergence of new developmental pathways or alterations to existing ones, also leading to significant morphological changes. Both of these types of developmental changes have been observed and studied in numerous examples of evolutionary change.

What Types of Changes in the Regulation of Development Can