From the three examples listed below, which describe the occurrence of speciation?
I. Two plant populations of the same species are pollinated by different species of insect that are active at different times of the day. There is no overlap between when the two insect species are active. Mutations occur within the two populations leading to them to become genetically distinct from each other.
II. A small number of lizards float on a wooden log and start a new population on another island. Mutations occur within the two populations leading to them to become genetically distinct from the original population.
III. A mutation occurs that causes a small population of a species of plant to become tetraploid instead of the usual diploid cells.
Back in evolutionary history, the ancestors of giraffes used to have much shorter necks. At this time they possessed a nerve called the laryngeal nerve that travels from an area just below the brain into the brain. At this time the nerve looped under a blood vessel that was quite close to the brain and this allowed the nerve to be short and send impulses very quickly.
Over time as the giraffe evolved to develop a longer neck, the laryngeal nerve also grew longer. Although it still started just below the brain and sent impulses to the brain, the restriction of looping under the blood vessel near the heart prevented the nerve from avoiding growing with the neck of the giraffe.
The image below shows the structure of the laryngeal nerve in the giraffe.
Which of the statements below correctly describes the evolution of the giraffe laryngeal nerve?
The evolution of the laryngeal nerve provides evidence for the concept of punctuated equilibrium.
The evolution of the laryngeal nerve is an example of stabilising selection.
The evolution of the laryngeal nerve provides evidence for the concept of gradualism.
The evolution of the laryngeal nerve provides evidence against natural selection because natural selection would never allow for such a flawed, inefficient structure to develop.
