Are there long, gradual, pathways of functional intermediate structures, separated by only one or perhaps a few mutations, leading to every single species, and every single design and structure in all of biology? As we saw last time, this has been a fundamental claim and expectation of evolutionary theory which is at odds with the science.* If one mutation is rare, a lot of mutations are astronomically rare. For instance, if a particular mutation has a one-in-a-hundred million (one in 10^8) chance of occurring in a new individual, then a hundred such particular mutations have a one in 10^800 chance of occurring. It’s not going to happen. Let’s have a look at an example: nerve cells and their action potential signals.
[* Note: Some evolutionists have attempted to get around this problem with the neutral theory, but that just makes matters worse].
Nerve cells have a long tail which carries an electronic impulse. The tail can be several feet long and its signal might stimulate a muscle to action, control a gland, or report a sensation to the brain.
Like a cable containing thousands of different telephone wires, nerve cells are often bundled together to form a nerve. Early researchers considered that perhaps the electronic impulse traveled along the nerve cell tail like electricity in a wire. But they soon realized that the signal in nerve cells is too weak to travel very far. The nerve cell would need to boost the signal along the way for it to travel along the tail.
After years of research it was discovered that the signal is boosted by membrane proteins. First, there is a membrane protein that simultaneously pumps two potassium ions into the cell and three sodium ions out of the cell. This sets up a chemical gradient across the membrane. There is more potassium inside the cell than outside, and there is more sodium outside than inside. Also, there are more negatively charged ions inside the cell so there is a voltage drop (50-100 millivolt) across the membrane. (read more …)