FRIDAY 2-5PM CARLA
YAN QIU (KEN) LIU
Essay Discussion-“Peer reviewed primary research article”
z3284618
Word Count: 507
Cooper. A., Lalueza-Fox. C., Anderson. S., Rambaut. A., Austin. J. & Ward. Y. (2001). Complete
mitochondrial genome sequences of two extinct moas clarify ratite evolution. Nature, 409, 704-707.
This report is to describe the simple analysis on the biological science article by Cooper, Anderson,
Rambaut, Austin & Ward’s 2001 work on the topic of “Complete mitochondrial genome
sequences of two extinct moas clarify ratite evolution”.
The article discuses topics within the discipline of zoology mainly involve the evolution of living
and extinct large flightless birds; include tracing their family origin, migration routes isolated by
tectonic plate activities, distribution and their extinction. Though as with most other evolutionary
studies especially for ancient extinct animals, knowledge in genetics also played a major role in
assisting this research. More specifically, authors of this paper used genetics investigation such as
genetic sequencing of mitochondrial genome (mtDNA) to facilitate their ground-breaking
hypothesis in ratite origins. It is clear that in many instances, not only limited to the study of
evolution, that knowledge in various fields of science needs to work together in order to achieve
a serious finding. In a speculative tone this might explain the need for six authors to complete
this four pages research.
The article was published on 8th February 2001 by Nature, a journal publication distributed by the
Nature Publishing Group trading under the privately held Macmillan Publishers Ltd that is wholly
owned by the North American umbrella division of the Georg von Holtzbrinck Publishing Group.
Nature is a prominent weekly journal publication representing one of the paramount sources of
ground-breaking original articles across all science disciplines. As the journal is widely distributed
and published in many languages, having Cooper et al (2001)’s finding featured in Nature
significantly boosted their international prestige and most likely resulted in dramatic increase in
funding for their respective research.
Cooper et al (2001)’s research article demonstrated the use of ancient DNA techniques such as
comparing DNA sequences and DNA base pairing to investigate the possible origin of large
flightless bird called ratite through now extinct species of moa and taxa. Although the details and
data tables in this article remained mysterious after several reviews, a general not-so-accurate
interpretation of the purpose of this study could have something to do with using mtDNA
sequences from several families of ratites, including fossils from extinct moa and elephant birds
as well as bones from kiwi and emus. The experimenters were able to compare the DNA distance
in order to form ratite phylogeography Cladogram, a rotated tree diagram depicting the
evolutionary distance of species from ratite’s common ancestors relative to time. They then later
used carbon dating techniques to estimate fossil age in order to explain the effect geological split
of continents and its effect on the migration and evolution of sub-species of ratite, including the
two specimens of moa fossil and other living or extinct rhea and ostrich samples. As a result of
calibration between historic fossil age and their mtDNA sequences with researchers’ hypothesis
on basal separation, they were able to clear out some competing hypothesis on the origin of all
ratite though they were not able to pinpoint the exact location or time period due to very poor
ratite fossil records.