DISAMPING KANAN INI.............
PLEASE USE ........ "TRANSLATE MACHINE" .. GOOGLE TRANSLATE BESIDE RIGHT THIS
..................
Tracking
turtles through time, study may resolve evolutionary debate
Date:
May 5, 2014
Source:
Dartmouth College
Summary:
Turtles are more closely related to birds and
crocodilians than to lizards and snakes, according to a study that examines one
of the most contentious questions in evolutionary biology. The research team
looked at how the major groups of living reptiles, which number more than
20,000 species, are interrelated. The relationships of some reptile groups are
well understood -- birds are most closely related to crocodilians among living
reptiles, while snakes, lizards and New Zealand's tuatara form a natural group.
But the question of how turtles fit into this evolutionary picture has remained
unclear.
..........................
Turtles are more closely related to birds and crocodilians
than to lizards and snakes, according to a study from Dartmouth, Yale and other
institutions that examines one of the most contentious questions in
evolutionary biology.
The findings
appear in the journal Evolution & Development. A PDF of the study is
available on request.
The research
team looked at how the major groups of living reptiles, which number more than
20,000 species, are interrelated. The relationships of some reptile groups are
well understood -- birds are most closely related to crocodilians among living
reptiles, while snakes, lizards and New Zealand's tuatara form a natural group.
But the question of how turtles fit into this evolutionary picture has remained
unclear. Are turtles more closely related to archosaurs (birds and
crocodilians) or to lepidosaurs (lizards, snakes and tuatara)? Or are these
other reptiles more closely related to each other than to turtles?
A growing
number of studies examining DNA sequences have suggested a close evolutionary
kinship between turtles and archosaurs, but those results were contradicted by
anatomical studies and a recent study of small biomolecules called microRNAs.
Because microRNAs are viewed by some as excellent evolutionary markers, the
conflict between the microRNA and DNA results meant the turtle-archosaur link
was viewed skeptically by many.
But the
Dartmouth-led team's research suggests the earlier microRNA conclusions were
erroneous, and instead indicates that microRNAs and DNA sequences yield a
common signal -- that turtles share a more recent common ancestor with birds
and crocodilians than with lizards and snakes.
Story
Source:
The above
story is based on materials provided by Dartmouth College. Note: Materials may be edited
for content and length.
Journal
Reference:
- Daniel J. Field, Jacques A. Gauthier, Benjamin L. King, Davide Pisani, Tyler R. Lyson, Kevin J. Peterson. Toward consilience in reptile phylogeny: miRNAs support an archosaur, not lepidosaur, affinity for turtles. Evolution & Development, 2014; DOI: 10.1111/ede.12081
Cite This Page:
Dartmouth College. "Tracking
turtles through time, study may resolve evolutionary debate."
ScienceDaily. ScienceDaily, 5 May 2014.
<www.sciencedaily.com/releases/2014/05/140505130526.htm>.