They know, but the person they originally responded to is making a faulty inference in the form of “pigs = mammals, mammals emerged at X date, pigs emerged at X date”. They aren’t properly recognizing that eggs are a distinct subset of unicellular organism (which I also think isn’t actually true of fertilized eggs) and you can’t infer from the set “unicellular organisms” having a trait that “eggs” has the same trait.
They know, but the person they originally responded to is making a faulty inference in the form of “pigs = mammals, mammals emerged at X date, pigs emerged at X date”. They aren’t properly recognizing that eggs are a distinct subset of unicellular organism (which I also think isn’t actually true of fertilized eggs) and you can’t infer from the set “unicellular organisms” having a trait that “eggs” has the same trait.