EVOLUTION

1) Explain why a species is most likely to undergo adaptive radiation when there is little competition for resources.

 

A species will likely undergo adaptive radiation when there is little competition for resources because the main competition will be between the species itself. That means any mutation that the animal will undergo will result in a resource for that mutation. For example with Darwin's finches, each mutation with the bill seize resulted in a resource for that finch. Each new finch bill size had its own niche with little competition allowing it to survive and that led to adaptive radiation. 

 

2) The Hawaiian Islands are home to about 30 species of very closely related plants called silverswords. Some are treelike while others are dwarf shrubs. They are found nowhere else on Earth. Use your understanding of adaptive radiation to describe their likely evolutionary past. 

 

It started with one species of silversword that arrived on an island. Then that species must have realized that there wasn’t much competition and there must have been evolutionary niches that were empty. Then the species of silverswords must have underwent adaptive radiation and filled that niche. 

 

 

3) Compare and contrast divergent and convergent evolution. Include examples to illustrate the similarities and differences. 

 

Divergent evolution is when a specific group of organisms evolved into several different forms. For example it is when a group of rodents evolved into a lot of different species of rodents. Convergent evolution is simply when different species evolve and gain similar traits. For example cacti which evolved in South America were native only to the Americas. Euphorbia look like cacti but are not cacti and are found in South Africa. Both are different species but live in similar environments and both evolved a similar trait involving spines that serve as a protective function. 

 

4) Many species of fish and waterfowl are darker on their upper surface and lighter coloured below.

a)What pattern of evolution is most likely at work?

Convergent Evolution because they are different species but they develop similar traits

b)Suggest possible selective advantages for this coloration

It blends the fish in with the ocean preventing it being seen by birds that can spot the bird from above and eat it. 

 

7) Snakes are not the only legless terrestrial vertebrates. Caecilians are a group of amphibians that also lack legs. Is this an example of convergent or divergent evolution. Explain your reasoning. 

Convergent Evolution because these are different species and they developed similar traits.