Ah, well that’s another reason cats should inherit the Earth. Cats are highly territorial. Unlike humans, they like a lot of space between them. Their carbon footprint will be much less than that of humans. 
An intelligent species that’s more territorial than humans sounds like a nightmare.
Only a nightmare for nosy cats. The biosphere will thank them, though.
Probably not, given that increasing urban density is one of the best solutions to fighting climate change.
Smart cats will have solved global warming by then.
Thank you. That’s more helpful than what I said.
Probably by killing all the humans. That’s really all it takes to put a stop to GW.
I have long observed that ailurophiles are some of the most fanciful, least anchored to even a tenuous string of scientific observation, of all the animal lovers. You can wave tomes of data in their faces but nothing has an observable effect on their beliefs.
What you have in cats are small semi-feral asocial predators. They are easily tamed, similar to other such species like ringtail cats and ferrets (both mustelids). For a complex of reasons, humans took such a shine to them that their geographical penetration is as vast as that of humans. There is nothing ecologically remarkable about them, except that human link, which is what has made them so hideously destructive.
Absent humans, they would disappear from most habitats quickly. With the ruination of the planetary ecosystem, of course, who the fuck knows. My bet is not going to be on cats, though. Coyotes maybe. Who are clever, work together to solve problems, and raise their families in a group. Not one of which applies to cats.
As far as that tool-using bipedal social animal niche, here’s to hoping it never opens again.
I mean, the biosphere will be “happiest” if no one ever evolves again that is able to harness fire.
But, assuming that your cats evolve the same level of intelligence that we have, they would still not be able to form a civilization if they have to have a lot of space between them. And whether they could form that intelligence would be debatable, as it is conjectured that it was our need to be social that lead to our advanced intelligence.
Either they will drop that trait, or they will not become a replacement for humans.
The only possible long-term benefit I can even conceive of from the existence of humans to life in general on Earth is that an intelligent species is probably the only possible chance of Earth life propagating (and thus evolving) beyond Earth. If we survive the next few hundred years, we might be able to colonize the rest of the solar system (with ourselves and Earth life we deem necessary or otherwise useful/beneficial) and even beyond over the following several thousand, thus greatly increasing the likelihood Earth life survives the death of Earth and our Sun.
Sure, but they don’t need to be human.
With the amount of interbreeding humans do all the time, I find it hard to imagine that there would be new species. The selection process could become supercharged in humans if there were a global catastrophe that very drastically reduced our numbers and separated the remaining populations, with no way to get back together for a few thousand years (or more?). As soon as humans get together, they start interbreeding again.
I really think you would benefit from reading a few books on evolution. The questions you ask seem to indicate some really basic misunderstandings.
This displays an incredible failure of understanding not just how evolution, but just sexual reproduction, works.
The only amount of cells that matter are in our testes and ovaries.
In which case, why hasn’t the Northern Mouse Lemur evolved more rapidly? And chimps should be evolving and speciating 3 times as fast as us.
I was actually referring to the complexity of our DNA thinking that a more complex DNA might be more likely to produce mutation it was a question not a statement even if it sounded like one
Then what did the number of cells have to do with it?
I’m just not that familiar with the vernacular
But this isn’t just a matter of terminology: It’s a matter of fundamental concepts. “Number of cells” isn’t just the wrong wording for “complexity of genome”: It’s a completely unrelated thing. Which indicates some very profound deficiencies of biological knowledge, without which any sort of meaningful speculation about evolution is impossible.
I may be missing something here. Someone starts a conversation hoping for some input from people who know a little bit about it so that they can get a better grasp on what they are thinking about. But because they don’t know much about the topic they are not supposed to ask. Is this site really about fighting ignorance or is iit about singing to the choir?
That ain’t no choir.
Nah, it’s more that when such a person questions the answers that they are given, based on nothing but personal incredulity and prior beliefs, that the people who were trying to answer the question start to get frustrated.