A Brief History
Have you ever wondered why you don't usually see marsupials frolicking about? It's because of their adaptability and competition with placental animals! Their adaptabilty of their species is also affected by their early birth. As said on the Home Page, marsupials have a limited evolution, which means they cannot adapt to their enviorment as easily as other species.
12.5 million yars ago, marsupials seperated from placental animals. How, you ask? A very long time ago, the 7 continents, and India, were stuck together into massive landmass called Pangea. Pangea then split up to form Laurasia and Gondwana. When the supercontinent Pangea split up, entire species were divided between Laurasia and Gondwana. This explains why our 7 continents have closely related animals and plants.
Where do marsupials go in all that, though? Well, the begining of marsupials is still foggy, but quite a few Paleontologists believe that marsupials began to evolve in what is now South America. As they evolved and spread around South America, a few must have slipped down into Gondwana before it and Laurasia split. Throughout many millenia, Laurasia slowly floated northward to the cold of the Arctic Ocean while Gondwana drifted southward to the tropial oceans of the Southern hemisphere. However, along with predetory placental animals and competition over food and space, marsupials could not adapt fast enough to combat the colder climate. In Gondwana, however, marsupials thrived in the warm climate. By this time, marsupials had migrated to Antarctica and Australia from Soutyh America. But as Antactica continued to drift further and further south, most of it's animals, and all of it's marsupials, died out. South America and Australia stayed in warm, hospitable climates that allowed their marsupials to thrive.
All was going well in South America until sea levels fell and a land bridge (now Central America) formed a pathway between North and South America. Placental animals from the North flooded into South America, making it even harder for marsupials to find food and shelter. Eventually the placental animals drove all the South American marsupials to near or total extiction. However, the Didelphis Virginiana (Virginia Oppossum) managed to migrate to the north, becoming the only surviving marsupial species in North America.
Australia, on the other hand, did not have the problem of invading placental animals. The Australian marsupials enjoyed a blissful isolation from the rest of the world, even when humans came from Indonesia to populate Australia, they lived harmoniously. But, when Europeans "discovered" Australia that was not quite the case. First, they dropped off their convicts (serial killers, rapists, arsonists) into the bush. Then they started to colonize the entirety of Australia (or Oceania, if you were to include New Zealand and other Oceanic countries), killing the Aboriginal people of Australia for "sport" (they were not a warrior people, like the Maori people of New Zealand). They brought animals from their homeland, like rabbits, to hunt. But these rabbits, once set off into the wild bush with no natural predators, did what rabbits do best. Multiple. Rabbits were soon overtaking the indigenous species, spreading across the Australian mainland and driving many marsupials to near extiction.
Since they have a hard time adapting to sudden changes in enviorment and placental animals often do not, the placental animals have driven marsupial to near total extinction! For example, South America used to be a marsupial paradise. But, when it's continetal plate collided with North America's, the North American placental animals flooded South America! Marsupials, suprised by the sudden invaision of these new animals, could not evolve fast enough to fight against the placental animals over food and territory, and died off.
12.5 million yars ago, marsupials seperated from placental animals. How, you ask? A very long time ago, the 7 continents, and India, were stuck together into massive landmass called Pangea. Pangea then split up to form Laurasia and Gondwana. When the supercontinent Pangea split up, entire species were divided between Laurasia and Gondwana. This explains why our 7 continents have closely related animals and plants.
Where do marsupials go in all that, though? Well, the begining of marsupials is still foggy, but quite a few Paleontologists believe that marsupials began to evolve in what is now South America. As they evolved and spread around South America, a few must have slipped down into Gondwana before it and Laurasia split. Throughout many millenia, Laurasia slowly floated northward to the cold of the Arctic Ocean while Gondwana drifted southward to the tropial oceans of the Southern hemisphere. However, along with predetory placental animals and competition over food and space, marsupials could not adapt fast enough to combat the colder climate. In Gondwana, however, marsupials thrived in the warm climate. By this time, marsupials had migrated to Antarctica and Australia from Soutyh America. But as Antactica continued to drift further and further south, most of it's animals, and all of it's marsupials, died out. South America and Australia stayed in warm, hospitable climates that allowed their marsupials to thrive.
All was going well in South America until sea levels fell and a land bridge (now Central America) formed a pathway between North and South America. Placental animals from the North flooded into South America, making it even harder for marsupials to find food and shelter. Eventually the placental animals drove all the South American marsupials to near or total extiction. However, the Didelphis Virginiana (Virginia Oppossum) managed to migrate to the north, becoming the only surviving marsupial species in North America.
Australia, on the other hand, did not have the problem of invading placental animals. The Australian marsupials enjoyed a blissful isolation from the rest of the world, even when humans came from Indonesia to populate Australia, they lived harmoniously. But, when Europeans "discovered" Australia that was not quite the case. First, they dropped off their convicts (serial killers, rapists, arsonists) into the bush. Then they started to colonize the entirety of Australia (or Oceania, if you were to include New Zealand and other Oceanic countries), killing the Aboriginal people of Australia for "sport" (they were not a warrior people, like the Maori people of New Zealand). They brought animals from their homeland, like rabbits, to hunt. But these rabbits, once set off into the wild bush with no natural predators, did what rabbits do best. Multiple. Rabbits were soon overtaking the indigenous species, spreading across the Australian mainland and driving many marsupials to near extiction.
Since they have a hard time adapting to sudden changes in enviorment and placental animals often do not, the placental animals have driven marsupial to near total extinction! For example, South America used to be a marsupial paradise. But, when it's continetal plate collided with North America's, the North American placental animals flooded South America! Marsupials, suprised by the sudden invaision of these new animals, could not evolve fast enough to fight against the placental animals over food and territory, and died off.