ICDESIGN writes:
I still have questions concerning that whole nerve stretching process from the TOE point of view but I will have to address them at a later date.
The routing of the laryngeal nerve is genetic, but not the stretching.
The elongation of the nerve during fetal development and later growth into an adult is not under any specific genetic control. It's just the general growth and development process. It just happens naturally. The genes in individual cells under genetic control respond to the pressures and needs of their neighboring cells to cooperate in the growth process, but there's no specific genes telling everything precisely how much to grow.
The growth and development process is under the control of hormones and other body chemicals that are themselves under genetic control, but these hormones and chemicals are not carrying specific signals of "grow 1mm in this direction and 2mm in that direction." It's much more like just a general command to grow.
Children that are small for their age are sometimes given growth hormone. The hormone has no specific instructions for each nerve, muscle and bone in the body. It's more like a signal sent to everywhere in the body to grow. The body itself with all its cells in cooperation figures out how much to grow so that all the joints and bones and blood vessels and nerves still fit neatly together.
Here's an interesting picture:
As neck rings were gradually added the nerves, bones, blood vessels and everything else all stretched naturally in response. That is all that happens to the laryngeal nerve during growth and development. There was never any need for specific genetic control to make it stretch.
--Percy
Edited by Percy, : Clarify.