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While the situation you identify isn't totally impossible it is fairly unlikely. Invasive/Disruptive species (those able to outcompete native species in simila

by throwaway2048 11y ago

While the situation you identify isn't totally impossible it is fairly unlikely. Invasive/Disruptive species (those able to outcompete native species in similar niches) in the modern world almost always come from larger landmasses. Presumably this arises because they are exposed to more intense evolutionary pressure from the larger amount of competitors/ecological niches present. https://en.wikipedia.org/wiki/List_of_introduced_species#Asia https://en.wikipedia.org/wiki/List_of_introduced_species#Asi... see for instance, almost no problematic species introduced into asia, a few in africa (although connected by land, the Sahara is a major barrier). Note also, the almost total lack of island species in this list. Although oweing to the large presence of europe in this list, this could be largely documentation or selective human action issue.

meric 11y ago
Remember, in the era dinosaurs the arrangement of Earth's landmass was radically different. Could it be possible where we've sampled the ancestors, they were actually on the island and whose evolution slowed down, and then later we discovered it's 'descendants' from the larger continent?
- throwaway2048 11y ago
  At the dawn of the Triassic and onwards to the early Cretaceous all the major continents were part of Pangaea. So assuming we arn't relying on just a few fossil beds to paint the picture, its virtually certain we are seeing the large continent species.
btilly 11y ago
It is true that invasive species are always more likely to come from somewhere else. And the bigger the somewhere else, the more of an opportunity it has had to come up with new invasive species. But this says nothing about the relative likelihood of producing an invasive species per square mile. In fact speciation events are believed to happen more often with small isolated populations. Most of the experiments are failures. But not all! See the theory of punctuated equilibrium for more.

meric 11y ago

Remember, in the era dinosaurs the arrangement of Earth's landmass was radically different. Could it be possible where we've sampled the ancestors, they were actually on the island and whose evolution slowed down, and then later we discovered it's 'descendants' from the larger continent?

throwaway2048 11y ago
At the dawn of the Triassic and onwards to the early Cretaceous all the major continents were part of Pangaea. So assuming we arn't relying on just a few fossil beds to paint the picture, its virtually certain we are seeing the large continent species.

btilly 11y ago

It is true that invasive species are always more likely to come from somewhere else. And the bigger the somewhere else, the more of an opportunity it has had to come up with new invasive species. But this says nothing about the relative likelihood of producing an invasive species per square mile. In fact speciation events are believed to happen more often with small isolated populations. Most of the experiments are failures. But not all! See the theory of punctuated equilibrium for more.