This is very misguided information you have here. There are organisms with simplistic eyes that do nothing more than sense light. Even this "feedback" mechanism can be extremely helpful. Think of heliotropism in many plants. Sunflowers, for instance - they turn their "face" to the sun and track it as it moves across the sky. "Half and eye" is a misnomer. But an eye of very little complexity can give its owner a whole host of new abilities.
Take a look at this single-celled creature upon which they have found an "eye" as one of its internals:
single-celled bug has the world’s most extraordinary eye
The eye does nothing but detect polarized light, and it uses this detection to go after prey that is otherwise nearly invisible. The creature, being a single cell, obviously has no nerves, nor brain, and yet its eye - arguably far less than "half" of one of our eyes - offers it tremendous advantage.
eyes that do nothing more than sense light.
For starters, even the article refutes your claim:
"There is no need for such a large, complex structure just to tell if it’s light or dark. What’s more,
his videos of Erythropsidinium reveal that it can point its
ocelloid in different directions"
"....unique and sophisticated eye, called the ocelloid..."
(from wiki)The
ocelloid.... is in fact one of the most complex known subcellular structures
Ocelloids contain subcomponents analogous to eye structures including the
lens,
cornea,
iris, and
retina.
[2] It can be divided into two substructures, the translucent, roundish
hyalosome and the heavily
pigmented melanosome, also known as the retinal body or pigment cup.
[5] The hyalosome serves as the refractive
lens of the ocelloid; it is surrounded by a layer of
mitochondria serving as the cornea and has constrictive rings analogous to the
iris. The retinal body has internal structure reminiscent of
thylakoid membranes in
chloroplasts and contains proteins related to
bacteriorhodopsin, a light-sensitive protein found in some
archaea.
[2][5]
Using
single-cell genomics and
electron microscopy techniques, the ocelloid has been shown to consist of multiple
membrane-bound organelles with distinct
endosymbiotic origins deriving from multiple lineages of
peridinin-containing
plastids.
[2]
yes, how simple!- and this doesn't even begin to get into how this collected information is connected,sent, processed and utilized to an advantageous physical response- without which it is utterly useless
So again it's a
fully functional and highly sophisticated eye, fully integrated into the organism. Even if not as sophisticated as ours. And all the literal digital DNA code required to implement this extremely complex system, all spontaneously blundered into existence by lucky random mistake?, hundreds of millions of years ago. Can we observe, measure, test or reproduce in any way.. ?
Of course not, rather it is concluded that it
must have happened, purely because that's what the 19th century theory demands, not the 21st century evidence