Featured Research

from universities, journals, and other organizations

'Reverse Evolution' In Real Time Provides Key Insights Into Basic Mechanisms Of Evolution

Date:
January 12, 2009
Source:
Instituto Gulbenkian de Ciencia
Summary:
Evolutionary biology tells us that replaying life's tape will not not look at all like the original. The outcome of evolution is contingent on everything that came before. Now, scientists have turned back the clock on the evolution in the fruit fly to provide key insights into the basic mechanisms of evolution.

Using fruit flies, researchers have recreated natural selection in real-time in the laboratory and provide the first quantitative evidence for natural selection on so-called standing genetic variation.
Credit: iStockphoto/Tomasz Zachariasz

Scientists have turned back the clock on the evolution in the fruit fly to provide key insights into the basic mechanisms of evolution.

In his book, Wonderful World, Stephen Jay Gould writes about an experiment of 'replaying life's tape', wherein one could go back in time, let the tape of life play again and see if 'the repetition looks at all like the original'. Evolutionary biology tells us that it wouldn't look the same – the outcome of evolution is contingent on everything that came before. Now, scientists at the Instituto Gulbenkian de Ciência (IGC) in Portugal, New York University and the University of California Irvine, provide the first quantitative genetic evidence of why this is so.

In this study, to be published online in the journal Nature Genetics, Henrique Teotónio and his colleagues recreated natural selection in real-time, in the laboratory (rather than based on inferences from fossil records or from comparing existing natural populations) and provide the first quantitative evidence for natural selection on so-called standing genetic variation – a process long thought to be operating in natural populations that reproduce sexually but which, until now, had never been demonstrated.

The researchers used laboratory-grown populations of fruit fly (Drosophila melanogaster), derived from an original group of flies, harvested from the wild back in 1975. These ancestral flies were grown in the laboratory, for two decades, under different environmental conditions, (such as starvation and longer life-cycles) so that each population was selected for specific characteristics. Henrique Teotónio and his colleagues placed these populations back in the ancestral environment, for 50 generations, to impose reverse evolution on the flies, and then looked at the genetic changes in certain areas of chromosome 3 of these flies.

Says Henrique, 'In 2001 we showed that evolution is reversible in as far as phenotypes are concerned, but even then, only to a point. Indeed, not all the characteristics evolved back to the ancestral state. Furthermore, some characteristics reverse-evolved rapidly, while others took longer. Reverse evolution seems to stop when the populations of flies achieve adaptation to the ancestral environment, which may not coincide with the ancestral state. In this study, we have shown that underlying these phenomena is the fact that, at the genetic level, convergence to the ancestral state is on the order of 50%, that is, on average, only half of the gene frequencies revert to the ancestral gene frequencies – evolution is contingent upon history at the genetic level too'.

These findings provide further insights into the basic understanding of how evolution and diversity are generated and maintained. On the one hand, it provides evidence for evolution happening through changes in the distribution of alleles in a population (so-called standing genetic variation), from generation to generation, rather than the appearance of mutations, from one generation to the next. On the other hand, as Henrique notes, 'It has implications for the definition of biodiversity: some of the 'reversed' flies may be phenotypically identical to the ancestral flies, but they are genetically different. How then do we define biodiversity?'

This study was funded by a Fundação para a Ciência e a Tecnologia grant awarded to Henrique Teotónio, who joined the IGC in 2003 as a group leader and currently heads the Evolutionary Genetics group and the in-house PhD Programme in Life Sciences.

Glossary:

  • Allele – one member of a pair or series of different forms of a gene.
  • Phenotype – any observable characteristic of a living organism, such as shape, size, physical features and behaviour. An organism's phenotype is a result of the activities of several of its genes, the environment or interactions between genes and the environment.

Story Source:

The above story is based on materials provided by Instituto Gulbenkian de Ciencia. Note: Materials may be edited for content and length.


Journal Reference:

  1. Teotónio et al. Experimental evolution reveals natural selection on standing genetic variation. Nature Genetics, 2009; DOI: 10.1038/ng.289

Cite This Page:

Instituto Gulbenkian de Ciencia. "'Reverse Evolution' In Real Time Provides Key Insights Into Basic Mechanisms Of Evolution." ScienceDaily. ScienceDaily, 12 January 2009. <www.sciencedaily.com/releases/2009/01/090111163023.htm>.
Instituto Gulbenkian de Ciencia. (2009, January 12). 'Reverse Evolution' In Real Time Provides Key Insights Into Basic Mechanisms Of Evolution. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2009/01/090111163023.htm
Instituto Gulbenkian de Ciencia. "'Reverse Evolution' In Real Time Provides Key Insights Into Basic Mechanisms Of Evolution." ScienceDaily. www.sciencedaily.com/releases/2009/01/090111163023.htm (accessed October 20, 2014).

Share This



More Plants & Animals News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) — Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) — He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Goliath Spider Will Give You Nightmares

Goliath Spider Will Give You Nightmares

Buzz60 (Oct. 20, 2014) — An entomologist stumbled upon a South American Goliath Birdeater. With a name like that, you know it's a terrifying creepy crawler. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) — Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins