Seminar 2 2011 Discussion Page Challenge 3

Quick Links
LENScience Senior Biology Seminar Series 2011
Rethinking Polynesian Origins Challenge 1
Challenge 2

Guide to discussion
How to start editing
How to start editing

-Be polite
-Assume good faith
-No personal attacks
-Be welcoming

How to edit a wiki movie or if you are in a rush, there is the quick-edit movie. These show you how to contribute to this discussion page.

If you cannot open the movie, here are the instructions as a pdf file

Here is an example of how to write in this page:

South City High School - Student MB    16th April 2pm

Please put your school name and write the date and time - then contribute your answer. 

This page is now closed for discussion

Rethinking Polynesian Origins - Discussion Page

Challenge Question 3

The research described in this paper challenges the traditional Lapita-only model of human settlement of the Pacific and suggests that there may have been several waves of migration into the Pacific, including the early Lapita migration. Use the information in the seminar paper and your understanding of biotechnologies to answer the following question:
Discuss the ways in which biotechnology has advanced the ability of scientists to investigate the hypothesis that there was more than one wave of migration into the Pacific.

Sacred Heart College - Student GerryT 11.30 a.m. 8th May

Biotechnology or, more specifically, molecular biotechnology, plays an extremely important role in determining migrational timing and patterns. This is because advancements in biotechnology has led scientists to the discovery of rings of DNA sequences in the mitochondria of humans and other animals in the 1960s, now referred to as mitochondrial DNA or mtDNA. This DNA structure has aided research progress in determining migrational timing and pathways into the Pacific because of two characteristics of this DNA structure, the first being that its inheritance is matrilineal, which means that it is inherited from the mother only, and the second being that it undergoes a predictable rate of mutation due to its proximity with free radicals produced from the process of cellular respiration. This has helped researchers a lot more than studying normal DNA because normal DNA is a combination of paternal and maternal DNA, making it all the more difficult to study as the differences wil be even greater, with the exception being the Y chromosome, which has also aided scientists in investigating migrational patterns to a certain extent due to the patrilineal inheritance of it. Armed with these advancements in biotechnology, researchers have been able to compare mtDNA sequences of Pacific island communities. Advancements in biotechnology have als improved scientists’ ability to extract DNA from ancient DNA samples, but also to sequence it by replicating it through Polymerase Chain Reaction. This allowed scientists to study the DNA samples obtained from remains found on the Pacific Islands and compare them for similarities. Through comparison, it will be possible to determine how long ago did the two communities separate based on the differences in mtDNA sequences as well as with the application of a molecular clock to determine how long ago did the changes occur. One such application of research in ancient DNA is the research in migrational paths through a commensal animal. One that is often selected is the kiore or pacific rat. Being unable to swim and often transported as a food source, in addition to its high reproduction rate and. thus, high mutation rate in the mtDNA, makes it a great choice. By studying the similarities and differences with the aid of a molecular clock, researchers are able to determine when the two communities of kiore were separated and how closely the two communities are linked. For example, research into mtDNA of kiore from the pacific shows three distinct haplotypes, with the third haplotype not fitting the expected of the pattern if there was only on migrational wave. This proves that they may have been another introduction of kiore into Polynesia after the Lapita introduction, leading to the conclusion that there was another wave of migrants reaching Polynesia after it has already been settled by the Lapita people.