“It’s a shame that so many of the scientifically illiterate had to jump in and fill the comments with so many tedious anti-science rants.”
Objecting to a theory is not anti-science. Einstein objected to Quantum Mechanics, and he was not anti-science. In fact, the attitude that a theory should not be questioned is itself anti-scientific.
Not to mention, applying the the label “anti-science” is a liberal shaming tactic that doesn’t befit the dignity of this online community.
There is so much variation possible within biology that defining what is a "species" is a difficult process. Since many things do not have concrete definitions, scientists must take care to define terms as they use them--which means that one scientist's definition of "species" is not necessarily universal.
That said, the definition I use is that a species consists of a group of organisms that do not naturally breed outside of their group. This definition only applies to multicellular organisms that have dedicated organ systems. The definition of species in microorganisms is a bit more problematic.
I should mention that species which came into existence within the span of human history (within the last 10,000 years or so) include such familiar species as cows and corn. These did not exist before agriculture, and do not exist apart from human civilization.
Since humans and chimpanzees cannot interbreed, I would say probably not. The test of interbreeding is only conclusive for positive results, not negative ones, since there are breeds that are obviously of the same species (because we have bred them), yet they can no longer interbreed, which are basically false negatives.
For all I know, humans and chimps are completely capable of producing viable mixed offspring that may even be fertile. We choose not to. Many thousands of years ago, homo sapiens in what is now Europe interbred with homo neanderthalensis, yet the two kinds of humans are generally considered separate species. Chihuahuas and Great Danes do not interbreed, yet are generally considered the same species. It is not the fault of scientists that nature does not draw clear boundaries for us to use when trying to decide what separates different species, or that our language groups organisms in a manner that doesn't reflect nature.
“The theory as formulated by Darwin and refined by countless scientists since then is very much based in the laws of physics.”
I like how you didn’t say anything about biology and genetics. Sometimes what you don’t say is as important as what you do. Now, standard evolution doesn’t step on too many toes when it comes to Physics, but abiogenesis certainly does, and that theory is a natural consequence of the same assumptions that figure in to evolution.
I did not specifically mention biology and genetics, because all hard sciences are, in fact, different aspects of physics. Evolution very much proceeds according to the laws of physics. I'm not sure why you mentioned abiogenesis; I'm fairly certain it was definitively disproved back in the 1600s.
Objecting to a theory is not anti-science. Einstein objected to Quantum Mechanics, and he was not anti-science. In fact, the attitude that a theory should not be questioned is itself anti-scientific.
When the theory forms the basis of a whole group of scientific disciplines (in this case, the life sciences), then objecting to it is, in fact, engaging in anti-science. I do not consider blanket rejections of theory as being in any way comparable to the normal testing and refinement of theory that scientists constantly engage in. I seriously doubt that Einstein blanketly rejected quantum mechanics; most likely, he was not convinced by the evidence and thought there might be other explanations for the observations that led to the description of quantum mechanics.