Consider this claim: Changes in environmental conditions always result in new ecosystems and loss of biodiversity characterized by an increase in the number of some species, the evolution of new species, and the extinction of some species.

Use at least three examples to support the valid ideas in the claim and refute the invalid ones. Then, draw a conclusion about the stability of ecosystems, how and what can affect the stability of ecosystems, and how changes in the environment may affect the types and number of living things in an ecosystem.

1) The increase in the species number can be explained by the process of natural selection. Species that are better adapted to new environmental conditions are more likely to survive and to reproduce since these species can occupy the niche of their non-adapted competitors. Thus species with higher fitness will increase their genetic variability (i.e., intraspecific variation), which is the primary matter for diversification and speciation.

2) Species evolution: environmental change may eventually lead to the evolution of species because only adapted individuals survive in changing climate conditions. However, it is important to note that this process is not associated with Lamarck's idea that species evolve through use and disuse in changing environments.

3) Extinction of species: Species that cannot adapt to the new environmental conditions eventually will disappear. In this regard, it is worthy to note that the climate change caused by humans is nowadays considered as the greatest threat to diversity and the main cause of current extinctions.