Australian aboriginals are hybrids, the same way most europeans and asians are. Every race that isn't 100% pure african is a genetic hybrid. The classic proof of this is the 2% of neanderthal DNA in caucasians. Amazing how only 2% of DNA can make such vasts differences between caucasians and "pure" humans/africans. Asians have even more neanderthal DNA than caucasians, but they also have other certain percentages of other now extinct subspecies.
As far as I know, australian aboriginals have no neanderthal DNA, and a boatload of other subspecies DNA, mostly donovan, if I am remembering correctly. Either that, or denisovan. Either way, they are literally the least human race there is, literally, due to their genetics.
However, it is also important to note that the reason why they look so hideous is mostly due to malnutrition. They are incredibly poor and thus are forced to the buy the cheapest foods they can at the stores. Since they no longer maintain their ancestral ways of foraging wild edibles and hunting fresh meat. The only difference between them and white people who eat a similar diet is that white people die from heart complications or diabetes before they look that bad. Or just get so damn fat they can't leave the house so you never see them in person.
If you look at really old pictures, their faces are still hideous, but other than that their ancestors were lean, fit, and intelligent. You can't hunt wild animals and remember where all the watering holes and edible plants are without being intelligent. So basically, if they would just eat right, they are a race of butterfaces. Which is still plenty fuckable if you yourself aren't a 10/10 Chad. However, at this rate, they are definitely going to eat themselves into extinction.