Islands spark accelerated evolution

The notion of islands as natural test beds of evolution is nearly as old as the theory itself. The restricted scale, isolation, and sharp boundaries of islands create unique selective pressures, often to dramatic effect. Following what's known as the "island rule," small animals evolve into outsize versions of their continental counterparts while large animals shrink. Giant tortoises and iguanas still inhabit the Galpagos and a few other remote islands today, but only fossils remain of the dwarf hippopotami, elephants, and deer that once lived on islands in Indonesia, the Mediterranean, and the Pacific Ocean. The fossil record suggests that these size changes occur rapidly after species become isolated on islands, but this long standing assumption has never been empirically examined in a systematic manner. Now, in a new study published in PLoS Biology, Virginie Millien confirms that island species undergo accelerated evolutionary changes over relatively short time frames, between decades and several thousand years.

Millien collected data from text, figures, and tables in an extensive survey of the published literature. From these datasets, she calculated a total of 826 evolutionary rates for 170 populations representing 88 species. Rates of evolutionary change, she found, decreased over time for both island and mainland species, with a slower rate of decrease for island species. The differences in evolutionary rates between island and mainland pairs also decreased over time, becoming statistically insignificant for intervals over 45,000 years. Overall, island species evolved faster than mainland species--a phenomenon that was most pronounced for intervals between 21 years through 20,000 years.

The finding that mammals evolve faster on islands, Millien argues, comports with the island evolution theory prediction that mammals respond to their new island homes with rapid morphological and size adaptations. The brisk pace of these changes may expla

Contact: Natalie Bouaravong
Public Library of Science

Page: 1 2

Related biology news :

1. World Wildlife Fund warns against iron dumping experiment near the Galapagos Islands
2. UF scientists discover new genus of frogmouth bird in Solomon Islands
3. New species and new records of marine species discovered in NW Hawaiian Islands
4. First Biodiversity Census of coral reef ecosystems in the NW Hawaiian Islands
5. Pacific Islands paradise protected
6. Introduced foxes transformed vegetation on Aleutian Islands from lush grasslands to tundra
7. Researchers learn what sparks plant growth
8. Food or its expectation sparks brains hunger centers
9. Nanogenerators may spark miniature machines
10. Global warming capable of sparking mass species extinctions
11. Molecular mechanism may explain how fevers spark seizures

Post Your Comments:

(Date:11/18/2015)... November 18, 2015 --> ... a new market report titled  Gesture Recognition Market - ... 2015 - 2021. According to the report, the global gesture recognition ... anticipated to reach US$29.1 bn by 2021, at a ... North America dominated the global gesture ...
(Date:11/17/2015)... , Nov. 17, 2015  Vigilant Solutions announces today ... its Board of Directors. --> ... recently retiring from the partnership at TPG Capital, one ... with over $140 Billion in revenue.  He founded and ... all the TPG companies, from 1997 to 2013.  In ...
(Date:11/12/2015)... , Nov. 12, 2015  A golden retriever ... Duchenne muscular dystrophy (DMD) has provided a new lead ... Children,s Hospital, the Broad Institute of MIT and Harvard ... Brazil . Cell, pinpoints ... dogs "escape" the disease,s effects. The Boston Children,s lab ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... QUEBEC CITY , Nov. 24, 2015 /PRNewswire/ - ... the request of IIROC on behalf of the Toronto ... this news release there are no corporate developments that ... price. --> --> ... --> www.aezsinc.com . --> Aeterna Zentaris ...
(Date:11/24/2015)... Muncie, IN (PRWEB) , ... November 24, 2015 , ... ... its newest Special Interest Group (SIG), MultiGP, also known as Multirotor Grand Prix, to ... in the last few years. Many AMA members have embraced this type of racing ...
(Date:11/24/2015)... 2015 /PRNewswire/ - Aeterna Zentaris Inc. (NASDAQ:  AEZS) ... remaining 11,000 post-share consolidation (or 1,100,000 pre-share consolidation) ... B Warrants") subject to the previously disclosed November ... 2015, which will result in the issuance of ... the issuance of such shares, there will be ...
(Date:11/24/2015)... ... November 24, 2015 , ... Creation Technologies would ... named to Deloitte's 2015 Technology Fast 500 list of the fastest growing companies ... FDA-cleared, Class II medical device that speeds up orthodontic tooth movement by as ...
Breaking Biology Technology:
Cached News: