Final answer:
Species are not always capable of adapting to new environments, and failure to adapt can lead to extinction. Evolution is not progressive but enables species to fit their niche and reproduce effectively. Rapid environmental changes or introduction to non-native habitats can severely challenge a species' ability to adapt.
Step-by-step explanation:
No, species are not always able to adapt successfully to a new or changing environment. The history of evolution is replete with examples of species that were unable to adapt and ultimately became extinct. Mesozoic Era dinosaurs are a classic case; despite their dominance at one time, they could not survive a significant shift in their environment. In the process of evolution, adaptations arise due to genetic variation and environmental pressures, but these adaptations are not indicative of progress in a linear sense. Evolution is not goal oriented; it does not strive to make creatures faster, stronger, or smarter. Instead, adaptations are simply traits that enhance an organism's ability to reproduce within its particular ecological niche. When environmental conditions change, those individual organisms with genetic variations that confer an advantage in the new conditions are more likely to thrive and reproduce. However, if the rate of environmental change outpaces the ability of a species to adapt, or if there is insufficient genetic variability within a species to facilitate adaptation, that species may be at risk of extinction. This was famously described in the Red Queen hypothesis, which postulates that organisms must constantly adapt and evolve not just for reproductive advantage, but to survive against ever-evolving opposing organisms in an environment that is always changing.
A complication in modern times is that human activity has vastly accelerated environmental changes and introduced exotic species to new environments at an unprecedented rate. Some of these species become invasive, outcompeting native species and altering ecosystems. Adaptation or extinction in such rapidly changing circumstances is a stark reality for many species. Finally, when species are removed from their natural habitat and placed into one with significantly different conditions—such as a different climate or exposure to different predators and food sources—their existing adaptations may be maladaptive, leading to poorer health or potential extinction.