New Bird Tree of Life

Bird Tree of Life JetzScientists last week proposed new evolutionary relationships among all 9,993 of the world’s known living bird species. In a letter published in the prestigious Nature journal, scientists reported on the use of DNA-sequence data to create a radiating phylogenetic tree, a revolutionary new bird tree of life (pictured left).

Walter Jetz (pictured right), an evolutionary biologist at Yale University in New Haven, Connecticut, was the leading author of the letter entitled “The global diversity of birds in space and time.” In an interview with science writer Virginia Gewin for Nature News, Jetz explains –

“This is the first dated tree of life for a class of species this size to be put on a global map.”

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Origin of the Feather

Snowy OwlAs the novelty generating the flight of birds, the feather, the most complex integumentary structure found in vertebrates, has long intrigued and fascinated naturalists.

Since Charles Darwin published The Origin of Species in 1859, however, the origin of the feather emerged as a contentious issue. The newfound association between feathers and dinosaurs has only intensified the problem.

 

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Smithsonian Human Evolution Exhibit

Smithsonian Human Evolution Exhibit“Human evolution is the lengthy process of change by which people originated from apelike ancestors,” explains the Smithsonian Institute exhibit (pictured left) entitled “Introduction to Human Evolution.” Continuing their explanation –

“Scientific evidence shows that the physical and behavioral traits shared by all people originated from apelike ancestors and evolved over a period of approximately six million years.”

 

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Exploring Human Evolution via DNA

Exploring human evolution via DNA was essential for twentieth-century evolution scientists. Charles Darwin, however, in The Origin of Species, never used the terms genetics, genetic, and genes until 1872, following the publication of the pea plant inheritance report of Gregor Mendel in 1866.

In his sixth edition, Darwin used the term “genetic” twice,  but only to express a genealogical idea, not as a molecular term. In the words of American evolutionary biologist Richard Lewontin,

“Darwin knew nothing about genes.”

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Sea Star Evolution

Cryptasterina pentagona Right 250Deciphering evidence for sea star evolution has long intrigued biologists. To explore speciation between two similar-looking sea stars, Jonathan Puritz (pictured below) of the Institute of Marine Biology at The University of Hawaii coordinated a research team to correlate the genetic and geographic differences between two Coral Sea species.

The team’s report, entitled “Extraordinarily rapid life-history divergence between Cryptasterina sea star species,” was published last week in the Proceedings of the Royal Society.

 

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Fossilized Mating Turtles

Mating TurtlesClues from fossilized mating turtles (pictured left) point to an enormous and sudden geological event. In last week’s edition of Biology Letters published by the Royal Society, Walter Joyce (pictured right) of Geosciences at the University of Tübingen in Germany.

The letter, entitled “Caught in the act: the first record of copulating fossil vertebrates,” updates information on the fossilized turtles discovered 30 years ago.

ABC NewsBBC NewsNational GeographicNew York Daily NewsMSNBC, FOX News, and Nature and Science journals featured the story, an unprecedented finding.

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Race for the Origin of Life Theory

RNA MoleculeThe search for an explanation for the origin of life started long before the publication of Charles Darwin’s Origin of Species in 1859. The first naturalistic theory of life arising from non-life, known as spontaneous generation, is attributable to Aristotle and ancient Greek philosophy.

Darwin rejected the Genesis account of creation written by Moses. Lingering doubts over the origins of life, however, forced Darwin to reject atheism and embrace agnosticism –

“The mystery of the beginning of all things is insoluble by us, and I, for one, must be content to remain an Agnostic.”

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Coelacanth Saga

Coelacanth Andrew J. Wendruff and Mark V. H. Wilson of the University of Alberta added a new dimension to the ongoing coelacanth saga this week in the paper “A fork-tailed coelacanth, Rebellatrix divaricerca,” published in the Journal of Vertebrate Paleontology.

In the paper, Wendruff and Wilson present a newly discovered coelacanth species found surprisingly on the rocky slopes of the Canadian Rockies, British Columbia.

The species named Rebellatrix divaricerca means “rebel coelacanth (with a) forked tail.” Far different from today’s Indian Ocean coelacanths, these ancient rebel fast-swimming predators further undermine attempts to develop a cohesive coelacanth evolution saga.

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Hominin Locomotion

BurteleThe sequence of biological events leading to hominin locomotion has long intrigued evolution scientists.

Last week, the journal of Nature reported on a hominin-like foot discovered in Eastern Africa.

Entitled  “A new hominin foot from Ethiopia shows multiple Pliocene bipedal adaptations,” the finding raises questions about the evolution of hominin locomotion.

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