Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New study sheds light on Galápagos hawk evolutionary history

05.10.2007
Scientists have used DNA sequences from feather lice to study how island populations of the Galápagos Hawk might have colonized the Galápagos islands

Scientists at the University of Missouri-St. Louis used DNA sequences from feather lice to study how island populations of their host, the Galápagos Hawk might have colonized the Galápagos islands, home to the endangered and declining raptor.

The study, recently published online in the journal Molecular Ecology (www.blackwell-synergy.com/doi/abs/10.1111/j.1365-294X.2007.03512.x), focuses on genes from three parasite species restricted to the Galápagos Hawk. The scientists also sequenced the same genes in the hawk to compare levels of genetic variation across these distantly related species. They traced the family tree of each species across the eight-island range, which were each colonized by the hawks and its parasites.

Because the parasite’s mitochondrial DNA was more variable than the host’s, the parasite’s family tree revealed how four of the hawk’s eight populations were related to one another -- the stepping-stone manner in which, over time, the hawks colonized first one island, then another and another, carrying their lice as they went. These relationships were previously obscured due to the hawk’s low genetic variation.

The scientists also suggested that their results demonstrate how symbionts of larger and more charismatic species, like hawk lice, can tell scientists a great deal about the history of life.

“The parasites are evolutionary heirlooms that were brought to the islands during the colonization of the hawk, but have continued to evolve along with their hawk hosts,” said Noah Whiteman, who conducted this study as part of his dissertation at UMSL and is now a postdoctoral fellow at Harvard University in Cambridge, Mass. “We had a great deal of trouble understanding how the island populations of the hawk were related to one another because of low genetic variation in the hawk’s DNA. The rapidly evolving lice that live their entire lives on these birds have helped illuminate their host’s evolutionary history.”

The Galápagos National Park and Charles Darwin Research Station are working to save Darwin’s archipelago from the fate of similar island systems. As part of this effort Patricia Parker, the E. Desmond Lee Professor of Zoological Studies at UMSL, forged a close working relationship with the two organizations to better understand the threats facing the island’s endangered birds. Parker initiated this collaboration by examining the basic biology and conservation genetics of the Galápagos Hawk and a few other species that she and her collaborators had studied previously.

A permanent resident found only in the Galápagos island, the Galápagos hawk has intrigued biologists for decades because of its unusual mating system, (cooperative polyandry) within some, but not all, island populations.

In this type of mating system, a single female hawk and up to eight male hawks, who are not close relatives, live in a stable territorial group and cooperate to rear chicks. This type of mating system is rare among birds, and understanding the sequence in which islands were colonized may reveal the point at which it first occurred, and thereby help us understand the evolution of cooperative behavior.

Kedra Tolson | EurekAlert!
Further information:
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-294X.2007.03512.x

More articles from Ecology, The Environment and Conservation:

nachricht Value from wastewater
16.08.2017 | Hochschule Landshut

nachricht Species Richness – a false friend? Scientists want to improve biodiversity assessments
01.08.2017 | Carl von Ossietzky-Universität Oldenburg

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>