This post is written against this page under the Probability tab on evolutionthelie.com
The post begins by claiming that the evidence the author has found supporting natural selection has been limited, aside from a few exceptions, to minor changes within existing species. The post also claims that genetic mutations are almost always harmful. Because nobody has ever seen “descent with modification produce a new species,” the author claims that “descent with modification from a common ancestor is not a fact.”
The final conclusion of this post is, technically, correct. Nobody knows for certain that all life stems from one common ancestor. I have found that all posts on this website are not refining a particular tool with which evolution cannot be dismantled, rather, it is attempting to throw any argument at evolution and hoping that it sticks. It is not a fact that humans descended from a common ape ancestor, but all the evidence we have acquired up until now has lead scientists to speculate that this is the most likely reality for the evolution of humanity. If evidence were to arise that starkly contradicted this belief, I think it would come with a high amount of scrutiny but I would hope that truth would ultimately win out. No alternate cause with a significant amount of supporting evidence has yet manifested. All this particular post is doing is promoting skepticism and encouraging a lack of belief.
On some of the facts within the post, beginning with the claim that “genetic mutations are almost always harmful,” the errors even within this post must be evaluated. Some mutations are harmful–but there is certainly the potential for beneficial outcomes or, more commonly, no effect whatsoever. Take the example of Sickle Cell Anemia in African populations. This disease, while it has tremendous downsides, essentially rends these individuals completely immune to the negative effects of malaria. While this originally was a mutation–nobody genetically engineered a person to be resistant to malaria–individuals with the mutation continued to reproduce. In other parts of the world, like the Nordic countries, the statistic of people with sickle cell is almost negligible. While we may not fully understand the mechanism at play, there must be a way to understand this trend. Natural selection could be wrong–but it is currently the best and most supported theory we have access to.
Additionally, it is clear that nobody has ever witnessed a clear speciation event. Likely, though, this is because of how long these events take to occur and our incredibly short lifetimes and, in the bigger picture, humanities incredibly brief stint on Earth so far. It is unlikely that an event will be possible to bear witness to during any persons lifetime and it is nearly impossible to glean anything meaningful about specific species that existed on earth thousands of years ago. No one person has ever seen a new species be produced, but perhaps humanity has and is just unable to communicate within itself effectively.