I would describe it as a weird phenomenon were two different breads mated together take make that breed or just something happened to the lobster when it was forming NOT SAYING THIS IS RIGHT I GUESSED IM GOING TO 9th GRADE NEXT YEAR
Certain genes that allow for a certain thing to happen are turned on or turned off as needed. A brain cell may have the gene needed to send electrical pulses to other brain cells or other parts of the body, whereas a heart cell may have the genes that allow it to contract to pump blood. (I don't know if those are real genes, but hopefully you get the idea)