New species don't arrive through hybridization. They change over time as groups are isolated from each other and the different groups adapt to their environment.
If man evolved?
by tornapart 427 Replies latest watchtower beliefs
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*lost*
It's very hard to get the head around all of the information.
that millions of years ago, species accidently wandered off and seperated far from each other,
when naturally, they always remain in contact, even loners like Leopards and Jaguars.
Then they somehow morphed into a new species.
Animals will travel for miles and miles to find a mate of their own kind.
And for the past 10,000 yrs at least, there hasn't been the emergence of any natural x breeding or evolution of new species. Only extinctions and new discoveries in unknown areas.
But we can see that by selective breeding from that type of animal, we can create variations within type. In nature, any abnormaities that pop up, are either killed by their own kind, exclede from the group and die, or are to weak to survive.
Arab horses are thousands of years old as a breed. But they are still the same. But if they weren't selectively kept and bred, and all the horses of the world amalgumated and were left run wild, they would lose most of their traites.
Same with dogs etc.
so I can see what you saying. At some stage millions of years ago, after coming out of the slime, animals just began to diversify and seperate into different kinds/types of animals.
I wonder why it just stopped occuring.
It is all fascinating
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jgnat
http://econdevelopment-socialchange.wikispaces.com/Early+Human+Migration
The new human story of survival and migration.
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Caedes
So then, is it theorised that a tribe of sapiens separated and left the trees for the savanah and evolved as a group to humans?
Sorry to be pedantic, but that would be a hypothesis rather than a theory. Fundamentally though yes, mainly due to the selection pressure required for us to evolve a larger brain.
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jgnat
New species continue to happen.
Groups of animals can become isolated from each other through geography.
Animals that have been selectively specialized and then are allowed to run wild together to interbreed may very likely revert to something closer to their ancestor. Or else the survivors will be the sturdiest and most adaptable to their environment. Those special traits are not lost, though. They reside as recessive genes in the descendants and can be brought back.
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jgnat
One story of specialization that I recall every time I see a tree, is when the first plant mutation grew upright, gaining more sunlight than it's neighbours and gaining a definite evolutionary edge.
Lost, only some mutations are failures. We would likely not even notice the successes.
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Comatose
Imagine it this way. If you could go back in time one million years, and take a horse from today with you, how different would it be from a primitive horse or its ancestors. In all likelihood it would be so different that it would be unable to produce offspring even though being the same animal at different points in time. I just threw one million yrs out there, so if that time period is wrong then just insert the correct time period in the illustration.
The point is that they change sometimes even drastically over time. So no one is saying a mammal crawled into the ocean and adapted fins and a blowhole to become a whale. They are saying the ancestor would be similar to a hippo and lived mainly in the water. Over millions of years small changes that made water living more successful resulted in the whale we have today. Not that a whale chose to adapt to water. It happens naturally over a very long period of time.
I think every person who finds these things hard to believe should read Jerry Coynes book Why Evolution Is True.. It explains it in simple terms for laymen like me. It makes sense when you just learn more about it.
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Caedes
when naturally, they always remain in contact, even loners like Leopards and Jaguars.
Animals will travel for miles and miles to find a mate of their own kind.
Earthquake, volcano or flood could cause the type of separation we are talking about, and as I said it is a group not an individual. For example the British isles were once connected to the European mainland, the English channel flooded and a new island was formed.
And for the past 10,000 yrs at least, there hasn't been the emergence of any natural x breeding or evolution of new species. Only extinctions and new discoveries in unknown areas.
This is incorrect, evolution is occurring all the time, hence why antibiotics are not as effective as they used to be. The bacteria evolve resistance to our antibiotics.
But we can see that by selective breeding from that type of animal, we can create variations within type. In nature, any abnormaities that pop up, are either killed by their own kind, exclede from the group and die, or are to weak to survive.
Genetic changes occur very slowly, so for example a giraffe wasnt suddenly born with a long neck, their necks grey longer over thousands of years. Any changes from one generation to the next would be almost impossible to see.
Arab horses are thousands of years old as a breed. But they are still the same. But if they weren't selectively kept and bred, and all the horses of the world amalgumated and were left run wild, they would lose most of their traites.
Same with dogs etc.
Exactly, if you allowed them to interbreed with any horse and didn't keep them separate. That is precisely the point.
so I can see what you saying. At some stage millions of years ago, after coming out of the slime, animals just began to diversify and seperate into different kinds/types of animals.
I wonder why it just stopped occuring.
It hasn't, my favourite example of recent evolution is the nylon bug.
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Witness My Fury
Some basic facts about it in these 2 films about Alfred Wallace you may have seen if in the UK:
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Comatose
Here Lost. This is an example of being separated and changing over time. Its from the book I keep mentioning (read it!) Copy pasting now.
A compelling discussion of the evidence for evolution, from geology, genetics, morphology, archeology, and more. He talks about interesting issues I hadn’t even realized were problems. Like, if evolution is incremental, how do different species arise out of the same parent species? The answer is that one group of individuals become isolated from the rest, and then the two groups can evolve separately. This makes a prediction: a species should be most closely related to another species that is separated from them by some kind of geographical barrier. And in fact, this is true. There are seven species of snapping shrimp on the west side of the Isthmus of Panama, and seven species of snapping shrimp on the east side. And the closest relative of each species of snapping shrimp on the west side is one of the seven species on the east side of the Isthmus of Panama. Which is just what you would expect if, 3 million years ago, there were seven species of snapping shrimp near Panama, then the Isthmus of Panama rose out of the water, separating each species into two groups, which then evolved independently of each other.
