Thank you for making me so wonderfully complex!
Psalm 139:14 NLT
"The chasm that exists between nerve cells and their proposed evolutionary
precursor cells has never been bridged by evidence, nor even by
theoretical just-so stories.
*The problem of the evolutionary origin of
the neuron is widely acknowledged by many evolutionists.
A neuron is another name for a nerve cell. It transmits information
within an organism (for example, sensory information) to the brain. It
communicates with other such cells by specialized connections, which are
actually switches called ‘synapses’.
In order to send messages, nerve cells employ a combination of
electrical and chemical signals, which can be excitatory or inhibitory.
The three neuron types are sensory neurons, motor neurons, and
interneurons.
Sensory neurons receive signals generated in the sensory
organs (such as the eyes, ears, skin, olfactory organs, and taste buds)
in response to light, sound, touch, pain, smell, and taste. They then
transmit the information to the spinal cord or brain for processing and
responding.
Motor neurons receive signals from the brain and/or the
spinal cord to regulate muscle contractions and glandular output.
Interneurons connect neurons to other neurons.
Dendrites extend out a few hundred micrometres from the soma or cell
body. The axon is the thin ‘cable’ along which the signal travels, and
nerve fibres consist of bundles of axons. It leaves the soma at a
swelling called the axon hillock. In humans, axons can be meters in
length. At the farthest tip of the axons are terminals called synapses,
where the neuron can transmit the signal across the synapse gap to
another cell.
Assuming that a functional nerve cell could have evolved, the next step
is for these nerve cells to evolve into nerve nets composed of neurons
with neurites (a collective name for both axons and dendrites) in a
mesh-like arrangement covering large parts of the animal body.
The nerve net requires directions to assemble the net to function,
involving a sensory system to receive information, and a muscle or other
system to respond to the information. Until these systems are in place,
the nerve net will be worse than useless and, at best, will just sit
there and waste space and nutrients.
The human brain, containing some 100 billion neurons, which together
form a complex network, has been called “the most complex object in the
known universe”.
Major questions in the evolution of neurons and nervous systems remain unsolved, such as the origin of the first neuron … Further complicating the evolutionary story is the conjecture that the
“Three kinds of gated channels probably evolved independently.”
For a nerve impulse to be carried forward, it must cross a gated
channel between the axon and the next cell structure. Gated channels are
molecules that form synaptic structures which control the messages’
travel from the sensory receptor across the neuron to the message
receptor....
The three kinds of gated channels are
1) the voltage-gated channel,
2) the stretch-gated channel, and
3) the ligand-gated channel.
The voltage-gated channel is a membrane that opens and closes in
response to changes in membrane potential (voltage). In neurons, the
sodium and potassium channels are examples of this type. The
stretch-gated channels respond to membrane stress and are common in
sensory cells.
Lastly, ligand-gated channels are a group of
trans-membrane ion-channel proteins which open to allow ions (including
Na+, K+, Ca++, and/or Cl−) to pass through the membrane in response to a
chemical messenger (i.e. a ligand), such as a neurotransmitter.
---A non-evolutionary explanation accounts for this situation quite well.
Each type was separately designed; thus, the
very implausible multiple evolution origin of the neuron and
evolutionary-loss hypothesis are unnecessary." CMI