Study proposes new method to investigate genetic hybridization

April 28, 2005

Exchange of genes between species through interbreeding is a potentially important force in evolution. Introgressive hybridization can facilitate evolutionary divergence and speciation by adding new genetic variation to populations. Until recently it has been thought to be rare, largely restricted to plants, and of little evolutionary significance. This view is changing. Even so its frequency may still be underestimated. Hybridization is most likely to occur in recently evolved species, yet these are the species in which it is most difficult to detect owing to strong genetic similarity deriving from their recently shared ancestry. In the July 2005 issue of The American Naturalist, Peter Grant and colleagues propose a method that teases out an effect on their genetic similarity due to hybridization, based on the fact that sympatric populations can exchange genes whereas allopatric populations cannot. Using microsatellite DNA data from Darwin's finches in the Galápagos archipelago, they compare sympatric and allopatric genetic distances in pairs of species and find a striking tendency for a species to be more similar to a sympatric relative than to allopatric populations of that relative. An important implication of this finding is that introgressive hybridization has been a persistent feature of the adaptive radiation throughout most of its relatively short history.
Sponsored by the American Society of Naturalists, The American Naturalist is a leading journal in the fields of ecology and evolutionary biology and animal behavior. For more information, please see our website:

Peter R. Grant, B. Rosemary Grant, and K. Petren, "Hybridization in the recent past"165:7 July 2005.

University of Chicago Press Journals

Related Evolution Articles from Brightsurf:

Seeing evolution happening before your eyes
Researchers from the European Molecular Biology Laboratory in Heidelberg established an automated pipeline to create mutations in genomic enhancers that let them watch evolution unfold before their eyes.

A timeline on the evolution of reptiles
A statistical analysis of that vast database is helping scientists better understand the evolution of these cold-blooded vertebrates by contradicting a widely held theory that major transitions in evolution always happened in big, quick (geologically speaking) bursts, triggered by major environmental shifts.

Looking at evolution's genealogy from home
Evolution leaves its traces in particular in genomes. A team headed by Dr.

How boundaries become bridges in evolution
The mechanisms that make organisms locally fit and those responsible for change are distinct and occur sequentially in evolution.

Genome evolution goes digital
Dr. Alan Herbert from InsideOutBio describes ground-breaking research in a paper published online by Royal Society Open Science.

Paleontology: Experiments in evolution
A new find from Patagonia sheds light on the evolution of large predatory dinosaurs.

A window into evolution
The C4 cycle supercharges photosynthesis and evolved independently more than 62 times.

Is evolution predictable?
An international team of scientists working with Heliconius butterflies at the Smithsonian Tropical Research Institute (STRI) in Panama was faced with a mystery: how do pairs of unrelated butterflies from Peru to Costa Rica evolve nearly the same wing-color patterns over and over again?

Predicting evolution
A new method of 're-barcoding' DNA allows scientists to track rapid evolution in yeast.

Insect evolution: Insect evolution
Scientists at Ludwig-Maximilians-Universitaet (LMU) in Munich have shown that the incidence of midge and fly larvae in amber is far higher than previously thought.

Read More: Evolution News and Evolution Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to