Okay humans and monkeys derived from an ancient common relative and that relative diverged into several different species.
It evolved into several different species due to Adaptation caused by the environment.
Why would that bring about several new evolved species instead of just adapting the current one into a better one? Wouldn’t the mating process bring it back into the mean? And when it finally developed into a new species through a statistically small mutation how would it mate with it’s old species to reproduce?
I hear that is evolution is pretty much fact yet I’m not totally convinced and don’t see how they could be.
There is no one measure of “better fitness” in a population of organisms. Your fitness measure depends on your environment, and what strategies you employ to survive there.
Speciation doesn’t occur as the result of a single mutation in a single individual. The process of divergence takes a long time, involves lots of genetic change, and involves a whole group of organisms.
Multiple species evolve primarily when groups are estranged for long periods of time. So, if some pre-humans moved out of the jungles into the plains, and others stayed in the jungles, those on the plains would be dealing with different circumstances, and thus would be selected for differently. Those that stayed in the jungle would maintain many of their attributes, such as climbing and fruit-eating, while the plains-dwellers would develop new attributes, like walking upright. After millions of years of these differences, the groups would diverge to the point where they couldn’t mate.
Let’s go thorugh a hypothetical. Let’s say there is some sort of rabbit called a Mabbit. It’s lived on an island and had realativly few predators- so it develops a lot of varieties. There are big Mabbits small Mabbits and medium Mabbits. In fact some males are so large and some females so small that bredding is physically impossible- but they are all connected through the midsize Mabbits.
Then one day a predator is intrudced (perhaps the sea level lowers and they walk from another island.) The small Mabbits are able to hide in small places. The large Mabbits can fight back and are generally avoided. The mid-size Mabbits become lunch. Now the species is split, there is no possibiltiy of interbreeding. So lets call the large ones Labbits, and the small ones Sabbits. Now over time the Labbits with larger teeth, sharper claws, and bigger muscels can better fight off the predators and are more likely to survive. On the other side, the Sabbits develop camoflage coats, even smaller bodies, and perhaps a system of warning calls. Now you have two very different creatures, the fighting Labbit and the socially complex Sabbit, that both came from a common ancestor the Mabbit.
If we ever go to Mars, we are likely to speciate as well. Until that time we are too good and finding ways to interbreed.
Naww, humans are too close to HW equilibrium and probably will be for the foreseeable future. Given our penchant for modifying our environments to suit us as opposed to the other way 'round, I don’t see Mars providing enough of a selective pressure to lead to speciation. But I suppose I am assuming that the gravity differential won’t be a strong enough pressure, which could well be mistaken.
Now, the life that we introduce to Mars. Especially during terraforming, that is gonna speciate like crazy. Hello Cambrian Explosion!
IIRC, the gravity on Mars is about 1/3 G. So that could be a big push. I guess it comes down to two factors. How often can shipments of Earthlings get to Mars? If its not often it will be hard to renormalise the genome. And will Mars be socially isolated? If Mars breaks ties with the motherworld for a century or two, it may give it enough seperate time to speciate. The Martians might meet teraforming halfway, as it were.