How is it that some creatures evolved from fish to land creatures such as Lions but we still have simple fish such as guppies? Why didn't these fish evolve to be something more complicated after millions of years?
Gizmo I think is the only poster I've ever seen only ever post in threads he's created. (random observation). To the topic at hand, evolution takes millions of years, fish may well evolve into something else in the next few million years. Depending on if adaptation requires it. Some change to the earth causing that. You can say that about all living things I would imagine. Look at humans...
Because maybe there is more to evolution, such as intelligent design. one of the things about evolution that perplexes me is how complex it is. The minute details to each evolutional instinct for each creature on earth. Thing of all of the human instincts we have body physically and mentally. And think about how long that should take to develop.
I don't believe in evolution (in the macro sense, anyway) but keeping with the theory, as long as these fish are fit for their environment(s), they can survive and keep replicating. It's like asking "why do we still have wolves and they aren't all dogs?" As long as wolves don't face something that causes them to go extinct, they'll be fine. Just because a line deviated into dogs doesn't mean the entire population of wolves will cease to exist.
Good observation. I noticed that he almost never responds or interacts in the threads after he posts them.
Animals evolve depending on the environment and pressures like predators and changes in food supply... If a fish randomly mutates and becomes a bit more able to spend some time on land, it can open up a new food source of everything on land...so those that are ever so slightly better at getting around on land keep moving in that direction and the ones that get around the best on land reproduce the most because they get the most food etc. That doesn't mean the fish that are good at being fish have to or should evolve in any other direction than being what they are. However, over time they did evolve - better fins, better ability to breathe, better functioning organs, better teeth, etc. If that little change makes them more likely to survive and reproduce then they'll keep moving in that direction. But there's no reason fish should "aspire" to be more than fish. If all the fish went and became mammals on land, then there would be a massive opening created for space and food in the seas and you'd get mammals going back into the water and acting like fish. Which is exactly what whales are. They used to have legs and walk around on land. If an opportunity presents itself, evolution will start to fill it.
Why do they need to evolve? Turtles and sharks have not evolved. The modern form of humans only evolved about 200,000 years ago.