Poisontree seeds from main island Poisontree seeds from small island Seeds from
ID: 45321 • Letter: P
Question
Poisontree seeds from main island
Poisontree seeds from small island
Seeds from other species of trees from main island
Flies from main island
0
0
145
Flies from small island
140
140
20
1. Describe how you would test the hypothesis that the small island and the main island flies are separate species under the phylogenetic species concept. Be as specific as possible about the methods, sampling, etc. You can collect the materials on the islands and do any additional work after being rescued. Show what your results would look like if the two sets of flies were different species AND if they were not.
2. Describe how you would test the hypothesis that the small island and main island flies are separate species under the biological species concept. Be as specific as possible about the experimental methods, sampling, statistical tests, etc. Again, you can do this work after you are rescued and have access to the necessary resources so dont be limited.
3. Assume that the flies meet the necessary criteria discussed above (i.e., Biological or Phylogenetic species concepts) to be considered distinct species. What is the most likely geographic mode of speciation (be specific)?
Poisontree seeds from main island
Poisontree seeds from small island
Seeds from other species of trees from main island
Flies from main island
0
0
145
Flies from small island
140
140
20
Explanation / Answer
1. phylogenetic species concept (PSC) is the concept of a species as an irreducible group whose members are descended from a common ancestor and who all possess a combination of certain defining, or derived, traits. Hence, this concept defines a species as a group having a shared and unique evolutionary history.
In the above problem, it seems that flies from the small island and flies from the main island have evolved from the same ancestor; and can interbreed; that is why they both are capable of growing on trees from other species of trees.
2.biological species concept (BSC) The concept of a species as a group of populations whose members are capable of interbreeding successfully and are reproductively isolated from other groups.
According to biological species concept, these two species are separate species and allopatric speciation has been observed in them. This I can say because , flies on main island are unable to grow on poison tree seeds.
3. Initially, both species had a common ancestor and were living on the main island. Here poisontree seeds were not present, so they did not develop the mechanism to feed on poisontree seeds.
Later on a geographical barrier, shifted some of the flies to small island from the main island, where poison tree seeds were abundant, but seeds from other trees which were present on main island were rare. Some flies grew on poisontree seeds and the rest were slowly eliminated from the population. At last, the population of poisontree seed feeding flies increased on the small island and a very small population of flies which fed on seeds of other species of main island were left.
Thus, poisontree seed feeding species became a new species by geographical isolation.