If I’m wrong, explain to me in very simple languagewhere and how did today’s dogs get their eyes?
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Reader's Digest Condensed Version:
Because ancient bacteria needed a way to orient themselves and generate food using light for energy. No, seriously.
Ancient microbes had multiple billions of generations to evolve chemical compounds capable of responding to light. Some of the first ones were rhodopsins, which function as light-powered proton pumps for energy generation in ancient bacteria, as well as part of a signaling system to trigger the cells to move toward, or away from, light, as needed. This gave them a survival advantage, and so the system was kept in subsequent generations in the descendants of those first bacteria.
Much, much later, some of their multicellular descendants developed cells and tissues that specifically contained the same system of light-sensitive chemical compounds, for the purpose of detecting and responding to light and shadow, giving them an advantage over other multicellular organisms that didn't have any ability to detect light in the majority of available niches. Over time, these cells became concentrated in specific spots on those organisms' bodies in an eyepatch or shallow sensory pit, giving them a weak ability to determine the direction from which light was coming (many simple animals keep their sensory tissues inside of a surface pit for protection). Again, this conferred a survival advantage, creating a positive feedback loop. Over multiple generations, deepening the pit became MORE advantageous, until the pit was finally completely covered except for a pinhole--and now the pit-eye had become a pinhole camera, capable of resolving images. Coverings kept parasites and debris out, and let light come in as long as the covering was transparent or translucent, and eventually the simple coverings became lenses as the covering thickened, and modern eyes were born. As before, changes that were advantageous were kept in later generations, and changes that weren't were discarded as the organisms that carried them died.
One of those organisms was the ancestor of all modern vertebrates, including the dog.
If this sounds unlikely to you, keep in mind that this process happened, independently,
many times in the animal kingdom. The eye evolved multiple times in multiple phyla, about forty times in fact--eyes are THAT useful, and the changes required to get them are far easier and more likely than you'd think. Irreduceable complexity flat-out doesn't exist, because each and every part of the system is already useful for something in some form, and each part becomes MORE useful when combined with others.
TL;DR version: Dogs have eyes because the earliest vertebrate ancestors of dogs also had eyes, and in most of its descendants there was no reason to lose them and every reason to keep them.
@#1765728: apparently Ray Comfort's never heard of bacterial conjugation. Sex has been around for a long time--before gender, in fact.
