Not sure how to frame this question, let me know if I am not clear and I will try to rephrase it. I am curious about the rate of change, I would assume the more species we have the more opportunities for change there would be. But I am wondering how significant that rate of change has been. An example ( not real figures) lets say it took 1 billion years for microscopic organisms to become fairly well diversified, then in the next billion years invertebrates established themselves, in the next billion we had reptiles, birds, and mammals. Does the process speed up exponentially or not really at all?
I think it’s the opposite - evolution happens as animals adapt to fill ecological niches. If those niches are already occupied, it’s harder for an animal to evolve to fill it. Look at the finches on the Galapagos, where they evolved to fill all sorts of roles that weren’t being filled in the local ecosystem, while just a few miles away, on the more populated and diverse mainland, they remained relatively unchanged.
I would think that the environment would have a lot to do with it. If you’re hanging around surviving and then a meteor hits your planet, there will be a LOT of selection pressure. Or, humans change the environment drastically in a short period of time, you survive or die.
Other, more quiescent times, probably have few selection pressures, but I’m not an evolutionary biologist. You should read some Dawkins.
What I had in mind when I posted this was I tend to believe that humans won’t be around forever I am thinking maximum 1,000,000 more years. Primates seem to be the most likely candidate at this time when it comes to intelligence and dexterity. But I have a feeling primates won’t fill the niche if humans disappear. Have any scientists speculated on what type of creature might fill our niche? My first guess would be rodents.
You should definitely read some Dawkins. This isn’t how evolution works. It’s not trying to create an intelligent species to dominate the planet, for example – humans have only been around for 200k years on the outside.
It depends on why humans disappear – was it a global nuclear holocaust that wiped out everything larger than microbes? Another meteor? Alien invasion? Star drive invented and we find a better planet?
I didn’t mean to suggest that evolution had a plan of some sort. I think that resources will drive the evolution. Depending on how we interpret things it kind of appears to me that lower carbon levels is what drove the advancement of mammals. Carbon levels have been inching slowly downward with sources for new carbon dying out. The industrial revolution reversed this process before the levels got too low and maybe bought a little time before they start dropping again. It looks like we have about 3 billion years left to evolve. Human egos don’t seem conducive to something that will last forever. If there is another intelligent species that takes over I bet it will not be as energy hungry or such a slave to it’s own ego.
If egos aren’t conducive to long-term (billions of years) survival, then the only way evolution could discover that is to try again, with either the same or different amount of ego, and see how long the new species lasts. Another species with out level of ego would have just as much chance of reaching the same point as us, as we did.
And a niche really only exists to the extent that there’s an organism that takes advantage of it. Right now, humans are filling the “intelligent tool-user” niche, but the planet got along just fine for billions of years without anything filling that niche. If we somehow go extinct, then there may or may not be another animal that evolves in that direction.
Part of my fascination with evolution is looking for patterns that might be evidence of a plan by a higher being. I don’t necessarily believe there is a plan but I like looking for it. The only thing I can come up with so far is that everything about humans seems to be about energy, we have an insatiable need for energy. All of our technology seems to be about harvesting energy sources and then using the energy. I am starting to suspect that if we have a purpose that might be it and then when all the carbon is recycled we will have served our purpose and then disappear. It is not hard t imagine 1 billion years from now some rat like creature developing a high intelligence when it comes to producing food, and a high social intelligence for living in close quarters. It is not hard to imagine crow like birds teaming up with the rodents and possibly other species. Things as crazy as this are possible.
I’m not sure I understand the connection between low carbon levels and the evolution of mammals.
Plant growth would have slowed considerably
All living things harvest energy. It’s called eating or photosynthesis, etc.
You’re not going to find any evidence of a plan from a higher being. If such evidence existed, religions would be all over that. Humans are just another animal that happened to stumble upon a great survival tool (so far) – intelligence and tool making.
As long as people think God is specially interested in us, we’ll always guess wrong about their plans. God is interested in everything equally. We are only specially special to ourselves.
As long as we believe consciousness is something we alone are blessed with, we’ll always guess wrong about everything.
Evolution is one of the ways the fabric of the surface of the planet heals its wounds and holes. Humans have made more wounds and holes in the living fabric of the world since the Great Meteor. I cannot imagine we will be able to survive all our own destruction more than a few more generations, considering we exhibit no ability to stop.
God is wrapping up his experiment with these intelligent social tool users, declaring it a failure. There will be a lot of evolution after we’re gone.
You can imagine billions upon billions of things happening a billion years from now. They all have exactly the same chance of becoming true, a number so close to zero that the number of zeroes after the decimal point is beyond our comprehension. And yet the number of meaningful ways to distinguish the craziness from one to another is also zero for all human purposes.
A billion years is just a noise from a human standpoint. We aren’t built for looking ahead 100 years. We’re very good at finding patterns, though. We want to find patterns because they help us in our lives. We’re so good at it that we can find patterns even when they don’t exist, like faces on Mars. Beware of pattern-making, especially in the future.
Once single cells came along (and how did that happen is THE big unanswered biological question), the next big step was the evolution of nucleated cells–eukaryotes. This took well over a billion years and–who knows–might never have happened. That is, IMHO, the biggest unknown in the Drake equation. It apparently happened what a big cell ate a smaller one and the smaller one managed to avoid digestion and take up residence, and also reproduce when the big cell did. Then somehow the small one evolved to hold the genetic material of the big one. Somehow. From that point, multicellularity evolved and the rest is details.
As for intelligence, the dinosaurs were around for, IIRC, 165 million years, were at least somewhat bipedal with arms that could have become tool using and never developed anything like human intelligence.
If any species tries to follow us, they will find an earth sadly depleted in natural resources.
I don’t disagree with what you are saying in principle. I think the destruction we are doing is not only beneficial but necessary for life on earth to continue a bit longer. This is a very long-term thing. that will likely not benefit humans during our reign. I feel it starts to suggest some kind of pattern possibly. I start feeling sometimes that evolution has an intelligence of its own.
This is the whole point of my thread. Humans are replenishing resources by returning sequestered carbon back into the biosphere. Co2 really speeds up plant growth and even makes them more water efficient.
I’m still not clear what that has to do with evolution.
Plant life is the basic food source for everything. More carbon more plant life, less carbon less plant life. Animals would have evolved around that to a large degree.
It took about 1.5 billion years of evolution for the first prokaryote/bacteria cell to evolve into eukaryotic cells. Likely from multiple prokaryotes forming symbiotic relationships.
By comparison, multicellular life has really only existed for 530 million years since the cambrian explosion. Virtually all multicellular plants and animals evolved in the last 530 million years. There were some multicellular life before that, but not like after.
So in that regards, evolution did seem to occur faster. I don’t know why it took 1.5 billion years for eukaryotes to evolve from prokaryotes, but the human brain tripled in size in only 2 million years.
Yeah but the levels of carbon in the environment are microscopic. They can affect the climate, but before industrialization the climate was maybe 0.028% CO2, now its about 0.042% CO2. Does a change that small really affect plant life much?
By comparison, during the age of giant insects, the air was about 30% oxygen, vs 21% now.