Analogy in evolution is the development of similar or analogous structures in distantly related species occupying the same environment. This is because the species have developed similar adaptations, over time, that enables them to survive in their environment.
The two different cactus species look similar because they live in the same environment. They have evolved similar structures, analogous structures, to adapt to this environment.
<span>When the surface layer was dug up, the permafrost was exposed. When the weather warmed, this exposed permafrost would have melted and become soggy, causing the ground underneath the tracks to shift.</span>
