Chicken and the Egg, for 5-year-olds
First, let&#x27;s be clear that the &quot;ape mother&quot; answer implies a distinction between humans and other apes, which is not true. We are all born of ape mothers, because humans <i>are</i> apes. Another issue is that &quot;human&quot; can refer to the Homo sapiens species, or it can also refer to any species in the genus Homo, depending on context and preference.<p>With that out of the way, the biggest problem here is that &quot;species&quot; don&#x27;t actually exist. There are several different definitions, and they each have arbitrarity and&#x2F;or striking exceptions. Species are just an intellectual tool humans invented to help us organize our understanding of how different living things are related to each other, but evolution is gradual and messy and doesn&#x27;t care much for clear separations.<p>So the answer to &quot;who was the father of the first human mother&#x27;s children&quot; depends on which definition of &quot;species&quot; and which definition of &quot;human&quot; you want to use. If you go with the common idea of &quot;two things are different species if they can&#x27;t have fertile offspring together&quot; (and ignore all the asexual reproduction and fertile hybrid exceptions), and &quot;human&quot; meaning just Homo sapiens, then... well, you&#x27;re screwed, really. Because by that definition, the only possible father of the first human&#x27;s children would have to be one of their siblings, as they definitionally couldn&#x27;t reproduce with any other existing creatures.<p>I&#x27;m not ruling out that such inbreeding happened; however... as I said, to use that definition, you need to ignore fertile hybrids, which is a problem because we <i>know</i> Homo sapiens interbred with other Homo species -- we have the DNA in ourselves to prove it. We are all fertile hybrids in that regard. Meaning the actual father would probably have been a pre-sapiens human species. So perhaps you&#x27;d prefer to use the morphological definition instead: &quot;humans are the creatures who look most like modern humans&quot;. Obviously, that gets messy and arbitrary, too, because different humans look different, and finding a &quot;different enough&quot; threshold is more preference than anything else. But ignoring that problem, the answer becomes the same: &quot;the father of the first modern-looking human was a species that didn&#x27;t look modern&quot;.<p>Same goes for the genetic definition of species as well; the first human whose DNA was &quot;different enough&quot; for us to call it a modern human had children with someone whose DNA was &quot;different enough&quot; to call it &quot;not a modern human&quot;.<p>In the end, the answer is approximately the same: the father of the first modern human would have been a different hominid species.