Why did the other Homo species die out, and are they species?

Question

Were they at a disadvantage for their intelligence, or the environment, or what. Why are Homo sapiens still thriving and the others gone?

Answer 1

Some believe H. erectus was canibalistic. The period of overlap when one species was essentially replacing the previous species, usually was relatively brief. The more successful species continued to undergo evolution, mating with both the old and new, eventually it evolved to the point where it could no longer successfully breed with the previous version to create a new "old" organism. Maybe, the behavior didn't change other than after s*x, no new organism was created. If this were the case, the more evolved would continue multiplying while the less evolved wouldn't.

Answer 2

We were better equipped to survive and had bigger

brains.

Answer 3

Considering that we have been waging wars on a very large scale for as long as there has been a history and in virtually every culture, it makes sense it went back far into prehistoric times.  That probably explains why others couldn't compete.  We fielded larger Armies and were more aggressive.  Our technology allowed us to have higher populations.

Answer 4

evolution

Answer 5

Each of the homo species was an advancement of the earlier ones. They were better able to deal with their enviorment and to reproduce.

The Neanderthal v. Early Modern Humans (EMH) case is illustrative of this. Neanderthals kept the same tool kit for their entire existence. EMH changed their tool kits to get more cutting edge out of the same amount of stone, developed art, and superseded the Neanderthals. They were light in build and appear better adapted to the steppes of Europe. The Neanderthal stayed in the forests and as the enviorment changed were restricted to smaller and more isolated areas.There's also indications that Neanderthals reproduced more slowly then EMH.

There doesn't appear to have been large scale conflict or genocide involved. EMHs simply were better able to live in the changed envoprment.