This cartoon has an identified author/artist-- hooray! Dan Lietha does the CreationWise cartoon for Answers in Genesis, and that link and his Facebook page both have treasure troves of fatuous nonsense in comic form.
It's a common trope of evangelical glurge to portray atheists as ignorant. Usually the portrayal is that atheists are ignorant of Christianity and the Bible, because it's simply impossible that a person could know anything about those and yet not be a Christian. There is no such thing as an informed rejection of the Truth (note: heavy sarcasm in use here).
But in this cartoon, the atheists-- who apparently are synonymous with evolutionists, because all atheists subscribe to evolutionary theory, and all people who subscribe to evolutionary theory are atheists (!)-- are ignorant of their own ideology. And not only that, but they're so ignorant of their own ideology that a school child who has just learned of it is able to point out an implication they'd never considered.
That implication is, of course, that if you evolve from pond scum (which is not actually what evolutionary theory says, but in the interests of time we'll gloss over that for now), all you are is just "rearranged pond scum," and therefore morality is meaningless and pointless. Genetic fallacy be damned, apparently.
Which is just a weird thing to conclude, because umm.....don't creationists believe we came from dirt?
Genesis 2:7 Then the Lord God formed a man from the dust of the ground and breathed into his nostrils the breath of life, and the man became a living being.But apart from that, and more importantly, who cares what we're made of?
If you were to construct a person out of silly putty, and that person had thoughts and feelings just like you do, it would be incumbent on you to treat that person morally. Because unlike Shylock, a person made of silly putty might not bleed when pricked, but if they can think and feel just like you, they would have the capacity for suffering just like you. They would have desires, just like you. They would have intellect, just like you. Which means that lying to them would be just as wrong as lying to a person made of blood and guts and bones and tissue. You know, what we-- all of us-- are actually made of.
So for my reductio ad absurdum cartoon I decided to depict two people whom I know to have considered the implications of evolutionary theory inside and out. Arguably, they have considered the implications of evolutionary theory more than anyone currently alive. I took these two people, and imputed to them the moral perspective that Lietha believes is the corollary of being an evolutionist. Just to see what that would look like.
Hat tip to Dan Linford, whose Facebook post on Lietha's cartoon brought it to my attention.