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The flowers that bloom in the Triassic, tra-la

Posted: Wed Oct 02, 2013 1:00 pm
by neufer
http://www.sciencerecorder.com/news/flowers-evolved-100-million-years-earlier-than-thought-plant-pollen-fossils-reveal/ wrote:
Flowers evolved 100 million years earlier than thought, plant pollen fossils reveal
Science Recorder | Jonathan Marker | October 02, 2013
<<An October 1 news release from the University of Zurich, Switzerland, announced the discovery of plant-like pollens that are over 100 million years older than the 140 million year-old uninterrupted sequence of fossilized pollen from flowers. It is around this time in the Early Cretaceous that scientists generally believe that flowering plants first evolved. However, the latest study documents flowering plant-like pollen that may have originated in the Early Triassic, some 252 to 247 million years ago.

Although a considerable number of studies have attempted to estimate the age of flowering plants from molecular data, no consensus has been reached thus far. Generally, depending on the dataset and method of analysis, estimates range from the Triassic to the Cretaceous.

Because very ancient fossils did not exist for flowering plants, molecular estimates could not be “anchored.” ”That is why the present finding of flower-like pollen from the Triassic is significant,” said Professor Peter Hochuli, of the University of Zurich.

Peter Hochuli and Susanne Feist-Burkhardt from Paleontological Institute and Museum, University of Zürich, analyzed two drilling cores from Weiach and Leuggern in northern Switzerland, and subsequently discovered pollen grains that bear a resemblance to fossil pollen from the earliest known flowering plants. Using a technique called Confocal Laser Scanning Microscopy, Hochuli and Feist-Burkhardt obtained high-resolution images across three dimensions of six different types of pollen.

Hochuli and Feist-Burkhardt documented different, but clearly related flowering-plant-like pollen from the Middle Triassic in cores from the Barents Sea, south of Spitsbergen, in a study conducted in 2004. The samples analyzed in the newest study came from a location that is 3000 km south of the previous site. “We believe that even highly cautious scientists will now be convinced that flowering plants evolved long before the Cretaceous,” said Hochuli.

A number of questions abound regarding the appearance of these ancient flowering plants. During the Middle Triassic, both the Barents Sea and Switzerland were located in the subtropics; however, the area of Switzerland was much drier than the region of the Barents Sea. To scientists, this implies that the plants had a broad ecological range. In addition, the pollen’s structure suggests that insects pollinated the plants. The most likely candidates for consideration were beetles, for the reason that bees would not evolve for another 100 million years.

The results of the study appear in the latest issue of Frontiers in Plant Science, in an article entitled, “Angiosperm-like pollen and Afropollis from the Middle Triassic (Anisian) of the Germanic Basin (Northern Switzerland).”>>

Re: The flowers that bloom in the Triassic, tra-la

Posted: Fri Oct 04, 2013 12:11 am
by saturno2
The mosses, conifers and flowering plantas, were the first plants
to come out the mariner medium and conquer the land.

Genome doubling down

Posted: Fri Dec 20, 2013 7:20 pm
by neufer
http://www.designntrend.com/articles/9729/20131220/dna-oldest-flowering-plant-solves-darwins-abominable-mystery-scientists.htm wrote:
DNA Of Oldest Flowering Plant 'Solves' Darwin's 'Abominable Mystery'-Scientists Say
Design Trend, Dec 20, 2013 <<Scientists have newly sequenced the genome of the Amborella plant, one of the two oldest lineages of flowering plants, for the first time, potentially addressing Charles Darwin's "abominable mystery" - the question why flowers suddenly thrived on Earth millions of years ago. It is considered to be the unique sole survivor of an ancient evolutionary lineage that traces back to the last common ancestor of all flowering plants. An understory tree is one that grows beneath a forest canopy without rising above it.

Scientists at Penn State University, the University at Buffalo, the University of Florida, the University of Georgia, and the University of California-Riverside sequenced the plant's genome and published a full description of the analysis in the journal Science. The genome sequencing of Amborella is expected to provide evidence for the evolutionary processes that paved the way for more than 300,000 flowering plant species that are found on Earth today. "In the same way that the genome sequence of the platypus - a survivor of an ancient lineage - can help us study the evolution of all mammals, the genome sequence of Amborella can help us learn about the evolution of all flowers," Victor Albert of the University at Buffalo said in a statement.

The plant's DNA provides evidence that the ancestor of all flowering plants, including Amborella, evolved following a "genome doubling event" which occurred about 200 million years ago. While some duplicated genes were lost over time, others took on new functions, including contributions to the development of floral organs. "Genome doubling may, therefore, offer an explanation to Darwin's 'abominable mystery' - the apparently abrupt proliferation of new species of flowering plants in fossil records dating to the Cretaceous period," Claude dePamphilis of Penn State University said in the statement.

This work provides the first global insight as to how flowering plants are genetically different from all other plants on Earth," said Brad Barbazuk, from the University of Florida said. "It provides new clues as to how seed plants are genetically different from non-seed plants." As the oldest surviving branch of flowering plants, the Amborella genome allowed researchers to estimate the linear order of genes in an ancestral plant genome called "eudicot," and to infer lineage-specific changes that occurred over 120 million years of evolution in the core eudicot. "Sequencing the genomes of individual Amborella plants across the species' range reveals geographic structure with conservation implications and evidence of a recent genetic bottleneck," Pam Soltis of the University of Florida said in a statement. "A similar narrowing of genetic variation occurred when humans migrated from Africa to found modern-day Eurasian populations.">>