defining 'evolution' in this sense is entirely at the discretion of the scientists
That’s utter nonsense. No general definition of evolution (whether as a general concept or whether via a specific mechanism, such as natural selection) requires sexual reproduction. Only some mechanisms do (in particular, obviously, sexual selection). Evolution by random mutation and natural selection (the core concept of the modern synthesis, which underpins all of modern biology) is completely independent of sexual reproduction.
For sexually reproducing organisms, speciation occurs when an organism can no longer reproduce with its predecessor
You’re misunderstanding something that is used for convenience, but is really a vast simplification. In reality speciation isn’t one defined point in time (hence it’s idiocy to ask what species the parents of the first human were — evolution is gradual!). To name just one specific example where your example breaks down: ring species [1].
[…] science still can't prove [speciation in sexually reproducing organisms].
Evolution by random mutation and natural selection (the core concept of the modern synthesis, which underpins all of modern biology) is completely independent of sexual reproduction.
Now all you have to do is prove that a "random mutation" created a new species.
I invite you to actually read that article all the way to the end. The classical examples of ring species may be oversimplifications but the concept of gradual gene flow is still very much intact (obviously).
As for your first point: don’t just selectively ignore what I’ve written and linked to. Beyond that, there is ample evidence. And it’s not hard to find, I’d invite you to honestly try. But I’ll stop here since I don’t have much hope of actually convincing a creationist. I posted the information for the benefit of others.
Comments
That’s utter nonsense. No general definition of evolution (whether as a general concept or whether via a specific mechanism, such as natural selection) requires sexual reproduction. Only some mechanisms do (in particular, obviously, sexual selection). Evolution by random mutation and natural selection (the core concept of the modern synthesis, which underpins all of modern biology) is completely independent of sexual reproduction.
You’re misunderstanding something that is used for convenience, but is really a vast simplification. In reality speciation isn’t one defined point in time (hence it’s idiocy to ask what species the parents of the first human were — evolution is gradual!). To name just one specific example where your example breaks down: ring species [1].
Once more, that’s utter nonsense (e.g. [2]).
[1] https://en.wikipedia.org/wiki/Ring_species [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1635482/
Now all you have to do is prove that a "random mutation" created a new species.
Second, you cite the Ring Species wiki, which links to an article which argues ring species don't exist. The proof is nebulous. https://whyevolutionistrue.wordpress.com/2014/07/16/there-ar...
I invite you to actually read that article all the way to the end. The classical examples of ring species may be oversimplifications but the concept of gradual gene flow is still very much intact (obviously).
As for your first point: don’t just selectively ignore what I’ve written and linked to. Beyond that, there is ample evidence. And it’s not hard to find, I’d invite you to honestly try. But I’ll stop here since I don’t have much hope of actually convincing a creationist. I posted the information for the benefit of others.