Hox genes are often similar enough in sequence across lineages that a gene from a distant relative can be used to restore function to a mutated Hox gene, such as when a chicken Hox sequence restores function to a Drosophila Hox gene. What is the best evolutionary explanation for this

"menstrual cycle is a complex cycle that consists of several processes. order of occurrence of steps in menstrual cycle are as follows:

1. high progesterone levels maintain the endometrium lining of the uterus.

2. endometrium lining breaks down and low levels of estrogen stimulate the pituitary to release fsh and lh.

3. fsh and lh stimulates the follicles to develop and the oocyte to produce estrogen.

4. rising estrogen levels suppress fsh production and development of other follicles.

5. a spike in lh causes follicle to rupture.

6. a breakdown of corpus luteum causes progesterone level to drop."

bacterium is not correct