PauloL wrote: ↑Fri Aug 18, 2017 12:35 pm
My question is: demonstrate how a new specimen shows up. You tell me: the "new" specimen was already there. The others wiped out.
I do not think I used the word 'new specimen' and I am not sure what you are asking.
All species already have variability. This arises because they reproduce sexually, so the offspring does not duplicate either of its parents, or through errors in duplication of the genetic material. Unless the particular type of variation is fatal, as long as the individual can produce viable offspring, the variation will persist. But if there is selective pressure, then some variations may be eliminated.
So the 'new' population with this variation was already there. What is new would be the elimination -by natural selection - of the part of the population without that variation.
I think you tend to miss the 'natural selection' bit, but that is the mechanism that is central to Darwin.
I'll tell the only example of evolution that I accept as scientifically sound.
Arising of mitochondria and chloroplasts through endosymbiosis more than 1.45 billion years ago.
This is evolution. In the end you have a new cell with new capabilities that didn't exist before.
[But how on earth you had all the ingredients for endosymbiosis? I wouldn't ask Darwin].
No, we wouldn't ask Darwin because Darwin lived before we had any understanding of such things. Darwin doesn't really address the origins of life. He seems to have thought it could have arisen from inorganic compounds, but that is not part of Darwinism. One could take the view that life was originally created by God, that would not be incompatible with Darwinism since Darwin is describing the subsequent development of species, not the origins of life.
As I have written before, it would be as well to avoid confusing the questions of evolution by natural selection and how life might have emerged.
It's like you have oxygen and hydrogen and in the end you have water. Not telling me that there were already water molecules dispersed, all the rest wiped out, and this is how water was created. Only one step better than any typical explanation from the Middle Ages.
Is this a point about natural selection or about how life might have emerged?
Whichever, I wouldn't see that any explanation is necessary. It is the nature of oxygen and hydrogen that if they are combined they form a molecule with certain properties i.e. water. In other words, a full explanation of what these two elements are would include '
they combine to make water'. And vice-versa;
What is water? A combination of oxygen and hydrogen.
Why? Because that is what 'water means. If it wasn't that combination it wouldn't be water.
More generally, I think there may be a fundamental problem around the idea of selection. We could argue that everything in the universe is 'selected' in that it must conform to what is possible. Life is 'selected for' in the sense that living things must also conform to those rules that apply generally.
But 'selection' in biology is different. In biology we have already made an artificial distinction between living and non-living. And we can go further and make an artificial distinction between kinds of living thing. So, if asked '
where does life come from?' in one sense the answer is '
us'. We choose to put certain replicating chemicals in a different mental box to other chemicals.
So, to study 'the origin of species' is to refine our understanding of those mental boxes, so that when we differentiate between two species we are clearer about what we mean, about what the word 'species' implies. As a result of Darwin we came to understand what the significance might be of certain observable differences, for example why although a whale and a fish closely resemble is each in many ways, a whale might still be better connected to land mammals. That organisms can change, so physical similarities and differences may not be reliable indicators of kinship.