We understand the argument. It's the evidence that's lacking to back it up.
What gets in the way of one's scientific 'understanding' of evolution is that there are no facts supporting it, no evidence substantiating it, and no observation of evolution currently occurring.
If you wish to put your faith in it, it is of no concern to us... but it's nothing but your faith, not science.
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You should actually try to understand the argument presented and respond to it. Let me help you out here.
Evolution works on the basis of speciation, which occurs by one species splitting off from another. The term used in the article was branching. The analogy is to refer to them as 'parent' and 'daughter' species. Like parents and offspring, it would not be surprising to see the parent survive at the same time as the offspring. Like parents and offspring, it is even possible that the parent could outlive the offspring.
There is nothing in argument that "blows a hole" in the theory of evolution. In fact, I don't even think you have a fully formed argument. Instead, we were indeed lucky to find these two species that have been assumed to be closely related also closely related in proximity and time by nature of the location and strata of the two finds. This confirms the earlier predicted relationship between H. habilis and H. erectus.