There are an infinite amount of worlds and parallel universes in existence, mostly because there are an infinite ways in which a person might think.

In one world Harry Potter saw and met Draco Malfoy and thought 'Pale, pointy faced git!'

In another he thought, 'He looks just like his mum and dad.'

The former thought led to the two boys becoming childhood nemesis, trying to best one another.

The latter led to a different thought altogether and thus another world. This is the story of that world.

'He looks just like his mum and dad.' Harry Potter thought as he stared at the outstretched hand in front of him belonging to a pale pointy faced git,'Of course his mum and dad look alike too.' He remembered the pale haired, grey-eyed, pointy faced couple he had seen fawning over the boy at the platform.

Ron and Draco were still arguing and Harry's thoughts veered to those of his new friend.

'Ron and his family look alike too,' He thought of the red headed family at the platform, the father had rejoined the lot and he had the same red hair and brown eyes that his wife and multiple spawn had too.

Harry's mind flashed to a conversation he had overheard while making breakfast for the Dursleys and Marge. That vile aunt of Dudley's had been talking about breeding and pedigrees. About how difficult it is to get dogs certified as belonging to a specific breed nowadays. "I don't like to do it, really I don't, but so many of my precious puppies come from matings of cousins and in some cases, even siblings. There's no way around it really, at least with the cousins and siblings I know they're good dogs, bad blood will out, there's no getting around that, can you imagine my darling Ripper being put together with some back alley lily-livered poodle? Breeding, it all comes down to that."

"Eugenics!" Came the shocked breathless whisper from Harry Potter, interrupting the glares that Ron Weasley and draco Malfoy had been sharing.

Thus began an obsession with bloodlines that changed the Wizarding world.

Well, that specific Wizarding world at least, World #85025 Sector W5E GB Gamma.