Question

14. is an evolutionary change in the rate or timing of developmental events. It can have a significant impact on body shape. 15. Humans and birds both have a Foxp2 gene, but it has diverged over many years of evolution. What type of gene is this? 16. Humans have several groups of Hox genes that have duplicated and evolved from the same ancestral gene. What type of genes are these?

Answer 1

14. Heterochrony   is a change in the timing of developmental events. An example of heterochrony is when a change in timing might slow down the development of the body, but the same does not alter the maturation of the reproductive system. This change yields an adult organism which has a form similar to the ancestral juvenile form.

15. Foxp2 is a trait which shows positive selection.

Foxp2 is a transcription factor, which means it controls the activity of other genes/ regulates expression of genes. It attaches or binds the DNA of other genes through a domain called forkhead domain. It plays an important role in mimicry in birds (such as birdsong). In humans, it is required for development of speech and language.

16. Hox genes are a gene cluster which are a type of homoeotic genes. Homoeotic genes code for transcription factors responsible for directing body structure formation.Hox genes are responsible for directing the body plan along the Anterior Posterior axis.

A gene cluster is a group of two or more genes found within an organism's DNA that encode similar polypeptides, or proteins, which collectively share a generalized function and are often located within a few thousand base pairs of each other.