BIO 370 Study Guide - Midterm Guide: Gene Regulatory Network, Antagonistic Pleiotropy Hypothesis, Hybrid Speciation
Document Summary
Modularity is a set of traits tied together in some way, which could be morphological, physiological or biological. Modularity avoids constraints on evolution by parsing some genes into different modules so that the genes are not all genetically correlated. If all genes are tied together that would be a constraint because they would all have to evolve together. Allopolyploid hybrid speciation can occur instantaneously (in one generation) when the complete nuclear genomes are inherited from different species. This speciation is instantaneous because a backcross to either parent would result in a triploid offspring (usually inviable). Homeotic mutations are those that transform a structure from one into another. Homeotic genes regulate the development of anatomical structures and mutations in these genes can cause displaced body parts. An example of a homeotic mutation are mutations in the hox gene clusters, which are master regulators of gene-regulatory networks that specify segment identity.
