Adaptation only exists and is present due to positive natural selection; P. natural selection is the power that makes adaptive evolution work. A trait has to be beneficial, increasing the chances of the organisms survival or allowing the organism to survive and reproduce successfully and the trait must also be heritable, it must be passed on to the organisms offspring in order for them to survive and reproduce as well, if reproduction with this trait continues more offspring with the same traits will arise, this trait will become more common. These are the two characteristics needed in order for a trait to go through positive natural selection. When an organisms Environment changes, those organism will either have to change with it in order to survive (Adaptation) or theyll die (Natural Selection). We see a good example of Adaptation in bears, if we look at the evolutionary history of bears we see that they all had a common ancestor and now looking at them we realize that they had to adapt to their environment keeping in mind that they live in different habitats. Another good example is located in kingdom Protista where we find Euglena; this protist has adapted to its environment and has developed a flagellum for locomotion where as other protists do not all have Flagella or a flagellum. Finally another great example is a vascular plant which adapted from early non-vascular plants. Vascular plants had to adapt and develop an internal transportation system.
2. Speciation is the evolution of a new species due to geographical, physiological and other factors that do not allow previously interbreeding populations to interbreed with each other anymore. Geographical/Biological Isolation and reproductive Isolation are what guide to speciation.
