First photo is of a pot originally containing just one florist plant, which died, but nature ensured that seeds formed were dispersed and germinated, and have now taken over the space left.
The second is of a tray of seedlings where I sowed the seed, and potted up the resultant seedlings.
Why are the seedlings in the middle of the pot, first photo, are so much stronger than the ones around the edges?
The possible explanation might be that the original plant tissue will have decomposed, and given that part of the pot some extra NURISHMENT.
Or a second explanation might be that these could be the seed of a particular cultivar, most likely to be a seedling Fancy Pansy looking at their leaves.
Letting nature go her own way regarding breeding is a lottery, but so easy in the early stages, the work, for the grower, comes when they all need their OWN space to develop.
Left in one pot only the fastest growing plant, will survive. The one dominant plant or plants extinguishes all others by denying them available light.