A cautionary tale in evolutionary theory is coming straight from the horses mouth. When ancient horses diversified into new species, those bursts of evolution werent accompanied by drastic changes to horse teeth, as scientists have long thought.
A new evolutionary tree of horses reveals three periods when several new species emerged, scientists report in the Feb. 10 Science. The researchers found that changes in teeth morphology and body size didnt change very much during these periods of rapid speciation.
This knocks traditional notions that rapid diversification of new species comes with morphological diversification as well, says paleontologist Bruce MacFadden of the University of Florida in Gainesville. This is a very sophisticated and important paper.
The emergence of several new species in a relatively short time is often accompanied by the evolution of special new traits. Classic notions of evolution say that these traits such as longer teeth with extensive enamel are adaptive, enabling an animal to succeed in a particular environment. In horses, the evolution of such teeth might permit a shift from browsing on leafy, shrubby trees to grazing on grasses in open spaces with windblown dust and grit.
You cant live on a grassland as a grazer and have short teeth, says MacFadden, an expert in horse evolution. Youll wear your teeth down and thats not a recipe for success as a species.
Similarly, a big change in body size can indicate a move to a new environment. Animals that live in forests tend to be smaller and more solitary than the larger herd animals that live in open grasslands.
Paleontologist Juan Cantalapiedra and colleagues compiled decades of previous work to create an evolutionary tree of 138 horse species (seven of which exist today), spanning roughly 18 million years. The tree reveals three major branchings of new species: a North American burst between 15 million and 18 million years ago, and two bursts coinciding with dispersals into Eurasia about 11 million and 4.5 million years ago.
The researchers expected to see evidence of an adaptive radiation, major changes in teeth and body size that allowed the new horse species to succeed. But rates of body size evolution didnt differ much in sections of the family tree with low and high speciation rates. And rates of change in tooth characteristics were actually lower in sections of the tree with fast speciation rates, the team reports.
Its very tempting to see some change in body size, for example, and say, Oh, thats adaptive radiation, says Cantalapiedra, of the Leibniz Institute for Evolution and Biodiversity Science at the Museum fr Naturkunde in Berlin. But thats not what we see.
Cantalapiedra and his collaborators speculate that during the periods of rapid speciation, the environment was so expansive and productive that there just wasnt a lot of competition to drive the evolution of adaptive traits. Perhaps, for example, North American grasslands were so rich and dense that there was enough energy for various species to evolve without having to develop traits that gave them an edge.
That scenario might be special to horses, says MacFadden, but it might not. Similarly, classic adaptive radiation scenarios might be true in many cases, but as this work shows, not always.
See more here:
Horse evolution bucks evolutionary theory - Science News
- EvolutionM.net - Mitsubishi Lancer Evolution | Reviews, News ... [Last Updated On: June 12th, 2016] [Originally Added On: June 12th, 2016]
- Evolution - Wikipedia, the free encyclopedia [Last Updated On: June 19th, 2016] [Originally Added On: June 19th, 2016]
- Darwin's Theory Of Evolution [Last Updated On: June 22nd, 2016] [Originally Added On: June 22nd, 2016]
- Evolution - Conservapedia [Last Updated On: June 28th, 2016] [Originally Added On: June 28th, 2016]
- History of Evolution | Internet Encyclopedia of Philosophy [Last Updated On: June 28th, 2016] [Originally Added On: June 28th, 2016]
- Darwin's Theory Of Evolution [Last Updated On: June 28th, 2016] [Originally Added On: June 28th, 2016]
- Evolution - Simple English Wikipedia, the free encyclopedia [Last Updated On: June 29th, 2016] [Originally Added On: June 29th, 2016]
- Evolution (2001) - IMDb [Last Updated On: July 5th, 2016] [Originally Added On: July 5th, 2016]
- Introduction to Human Evolution | The Smithsonian Institution ... [Last Updated On: July 7th, 2016] [Originally Added On: July 7th, 2016]
- EvolutionM.net - Mitsubishi Lancer Evolution | Reviews, News ... [Last Updated On: July 12th, 2016] [Originally Added On: July 12th, 2016]
- Evolution - Biology-Online Dictionary [Last Updated On: July 12th, 2016] [Originally Added On: July 12th, 2016]
- Introduction to Human Evolution | The Smithsonian Institution ... [Last Updated On: July 12th, 2016] [Originally Added On: July 12th, 2016]
- Evolution - Bulbapedia, the community-driven Pokmon encyclopedia [Last Updated On: July 12th, 2016] [Originally Added On: July 12th, 2016]
- What is Evolution - explanation and definitions [Last Updated On: July 12th, 2016] [Originally Added On: July 12th, 2016]
- Apps/Evolution - GNOME Wiki! [Last Updated On: July 12th, 2016] [Originally Added On: July 12th, 2016]
- History of Evolution | Internet Encyclopedia of Philosophy [Last Updated On: July 12th, 2016] [Originally Added On: July 12th, 2016]
- Recent Articles | Evolution | The Scientist Magazine [Last Updated On: July 16th, 2016] [Originally Added On: July 16th, 2016]
- Evolution - The New York Times [Last Updated On: July 25th, 2016] [Originally Added On: July 25th, 2016]
- Evolution : Pictures , Videos, Breaking News [Last Updated On: August 2nd, 2016] [Originally Added On: August 2nd, 2016]
- Faculty & Staff - Biology | Biology | High Point University ... [Last Updated On: August 8th, 2016] [Originally Added On: August 8th, 2016]
- Evolution (software) - Wikipedia, the free encyclopedia [Last Updated On: September 2nd, 2016] [Originally Added On: September 2nd, 2016]
- Evolution | Answers in Genesis [Last Updated On: September 2nd, 2016] [Originally Added On: September 2nd, 2016]
- Evolution (2001) - Rotten Tomatoes [Last Updated On: September 18th, 2016] [Originally Added On: September 18th, 2016]
- Human evolution - Wikipedia, the free encyclopedia [Last Updated On: September 22nd, 2016] [Originally Added On: September 22nd, 2016]
- Evolution - Wikipedia [Last Updated On: October 20th, 2016] [Originally Added On: October 20th, 2016]
- MyEvolution // About Evolution [Last Updated On: December 9th, 2016] [Originally Added On: December 9th, 2016]
- Evolution of the Web [Last Updated On: December 10th, 2016] [Originally Added On: December 10th, 2016]
- Evolution | Pokmon Wiki | Fandom powered by Wikia [Last Updated On: January 14th, 2017] [Originally Added On: January 14th, 2017]
- Evolution - RationalWiki [Last Updated On: January 14th, 2017] [Originally Added On: January 14th, 2017]
- Tracking the Evolution of Student Success - Inside Higher Ed [Last Updated On: February 6th, 2017] [Originally Added On: February 6th, 2017]
- Ivanka Trump's Beauty Evolution, From 1998 to Today Watch - Us Weekly [Last Updated On: February 6th, 2017] [Originally Added On: February 6th, 2017]
- Lumpy, hairy, toe-like fossil could reveal the evolution of molluscs - The Guardian [Last Updated On: February 6th, 2017] [Originally Added On: February 6th, 2017]
- USM Darwin Day: 'Genesis' a parallel to evolution - The Student Printz [Last Updated On: February 6th, 2017] [Originally Added On: February 6th, 2017]
- Cultural evolution and the mutilation of women - The Economist [Last Updated On: February 6th, 2017] [Originally Added On: February 6th, 2017]
- How Evolution Alters Biological Invasions - ScienceBlog.com (blog) [Last Updated On: February 6th, 2017] [Originally Added On: February 6th, 2017]
- Psychonauts in the Rhombus of Ruin Feels Like an Evolution of Double Fine's Adventure Game Roots - UploadVR [Last Updated On: February 7th, 2017] [Originally Added On: February 7th, 2017]
- The Evolution of Accessible Travel: 5 Podcast Takeaways - Skift [Last Updated On: February 7th, 2017] [Originally Added On: February 7th, 2017]
- Convergent Evolution: Why Some Plants Became Carnivorous - Science 2.0 [Last Updated On: February 7th, 2017] [Originally Added On: February 7th, 2017]
- The Queer Evolution of Kristen Stewart - Advocate.com [Last Updated On: February 7th, 2017] [Originally Added On: February 7th, 2017]
- Gold's Gym Regina rebrands to become Evolution Fitness - Regina Leader-Post [Last Updated On: February 7th, 2017] [Originally Added On: February 7th, 2017]
- Late-night hosts on the evolution of Trump: 'Dickish to dictatorish' - The Guardian [Last Updated On: February 7th, 2017] [Originally Added On: February 7th, 2017]
- Exhibition charts 500 years of evolution of robots - Phys.Org [Last Updated On: February 7th, 2017] [Originally Added On: February 7th, 2017]
- Blockchain: Investment (R)Evolution For Developing Markets - Forbes [Last Updated On: February 7th, 2017] [Originally Added On: February 7th, 2017]
- See the Evolution of the Famed Porsche 911 in 7 Photos - WIRED [Last Updated On: February 7th, 2017] [Originally Added On: February 7th, 2017]
- How evolution turned ordinary plants into ravenous meat-eaters - Wired.co.uk [Last Updated On: February 7th, 2017] [Originally Added On: February 7th, 2017]
- Are Evolution Fresh Drinks 'Poison'? - snopes.com [Last Updated On: February 7th, 2017] [Originally Added On: February 7th, 2017]
- The Evolution and Maturation of HPC in the Enterprise - CIO [Last Updated On: February 7th, 2017] [Originally Added On: February 7th, 2017]
- From Whoa to 'Wick:' The Evolution of Keanu Reeves - Film School Rejects [Last Updated On: February 9th, 2017] [Originally Added On: February 9th, 2017]
- 'Goldilocks' genes that tell the tale of human evolution hold clues to variety of diseases - Science Daily [Last Updated On: February 9th, 2017] [Originally Added On: February 9th, 2017]
- London exhibition charts 500 years of evolution of robots - Chicago Sun-Times [Last Updated On: February 9th, 2017] [Originally Added On: February 9th, 2017]
- Chimpanzee feet allow scientists a new grasp on human foot ... - Science Daily [Last Updated On: February 9th, 2017] [Originally Added On: February 9th, 2017]
- 'Evolution To Revolution' As New York Fashion Week Gets Political - NPR [Last Updated On: February 9th, 2017] [Originally Added On: February 9th, 2017]
- Orangutan squeaks reveal language evolution, says study - BBC ... - BBC News [Last Updated On: February 9th, 2017] [Originally Added On: February 9th, 2017]
- Deeper origin of gill evolution suggests 'active lifestyle' link in early ... - Science Daily [Last Updated On: February 10th, 2017] [Originally Added On: February 10th, 2017]
- From Tara Palmer-Tomkinson to Cara Delevingne: the evolution of the It girl - The Guardian [Last Updated On: February 11th, 2017] [Originally Added On: February 11th, 2017]
- Evolution gives rhyme its reason - Aurora News Register [Last Updated On: February 11th, 2017] [Originally Added On: February 11th, 2017]
- Evolution of in-car audio tech moving at 'speed of sound' - Times of India [Last Updated On: February 11th, 2017] [Originally Added On: February 11th, 2017]
- Scientists solve fish evolution mystery - Phys.Org [Last Updated On: February 11th, 2017] [Originally Added On: February 11th, 2017]
- The Difference Between Healthy Love & Unhealthy Love - Collective Evolution [Last Updated On: February 12th, 2017] [Originally Added On: February 12th, 2017]
- This Woman Was Raped & Forgave Him, So They Did A Ted Talk Together - Collective Evolution [Last Updated On: February 12th, 2017] [Originally Added On: February 12th, 2017]
- A primer on Darwin Day: Some religious groups embrace 'Theistic evolution' - LancasterOnline [Last Updated On: February 12th, 2017] [Originally Added On: February 12th, 2017]
- Pokmon Go Eevee evolution: How to evolve Eevee into Vaporeon, Jolteon and Flareon with new names - Eurogamer.net [Last Updated On: February 12th, 2017] [Originally Added On: February 12th, 2017]
- Evolution of baseball from power to speed has left SBs behind - Chicago Sun-Times [Last Updated On: February 12th, 2017] [Originally Added On: February 12th, 2017]
- More order with less judgment: An optimal theory of the evolution of cooperation - Science Daily [Last Updated On: February 12th, 2017] [Originally Added On: February 12th, 2017]
- How the horse can help us answer one of evolution's biggest questions - Raw Story [Last Updated On: February 12th, 2017] [Originally Added On: February 12th, 2017]
- China Is Now The World's Largest Producer of Solar Power ... - Collective Evolution [Last Updated On: February 13th, 2017] [Originally Added On: February 13th, 2017]
- Community Viewpoint: Evolution, like gravity, is much more than theory it is a fact - Kdminer [Last Updated On: February 13th, 2017] [Originally Added On: February 13th, 2017]
- See the Evolution of Movie Magic With Every Oscar Winner for ... - Gizmodo [Last Updated On: February 13th, 2017] [Originally Added On: February 13th, 2017]
- How the horse can help us answer one of evolution's biggest questions - Phys.Org [Last Updated On: February 13th, 2017] [Originally Added On: February 13th, 2017]
- How evolution alters biological invasions - Phys.Org [Last Updated On: February 13th, 2017] [Originally Added On: February 13th, 2017]
- The Evolution of Valentine's Day - Inside Science News Service [Last Updated On: February 14th, 2017] [Originally Added On: February 14th, 2017]
- Why evolution may be tech billionaires' biggest enemy - The Week Magazine [Last Updated On: February 14th, 2017] [Originally Added On: February 14th, 2017]
- Russell Westbrook is leading an evolution in NBA rebounding - Washington Post [Last Updated On: February 14th, 2017] [Originally Added On: February 14th, 2017]
- Eye Evolution: A Closer Look - Discovery Institute [Last Updated On: February 14th, 2017] [Originally Added On: February 14th, 2017]
- How evolution alters biological invasions -- ScienceDaily - Science Daily [Last Updated On: February 14th, 2017] [Originally Added On: February 14th, 2017]
- Evolution always wins: University of Idaho video game uses mutating aliens to teach science concepts - The Spokesman-Review [Last Updated On: February 14th, 2017] [Originally Added On: February 14th, 2017]
- Geneticists track the evolution of parenting - Phys.Org [Last Updated On: February 14th, 2017] [Originally Added On: February 14th, 2017]
- How this cockeyed squid shines a light on deep sea evolution - Christian Science Monitor [Last Updated On: February 14th, 2017] [Originally Added On: February 14th, 2017]
- Cockeyed squid shines light on deep sea evolution - Christian Science Monitor [Last Updated On: February 15th, 2017] [Originally Added On: February 15th, 2017]
- Fossil discovery rewrites understanding of reproductive evolution - Science Daily [Last Updated On: February 15th, 2017] [Originally Added On: February 15th, 2017]