Massospondylus Embryos

The Massospondylus embryos are in the news again thanks to a recent article in JVP.

I blogged about the 2005 Science paper here. Read the new story at National Geographic News

The 1st C4 Grass

Isotopic evidence of C4 grasses in southwestern Europe during the Early Oligocene–Middle Miocene. 2010. M.A. Urban, et al. Geology, First published online November 12.

image

A new analysis of fossilized grass-pollen grains deposited on ancient European lake and sea bottoms 16-35 million years ago reveals that C4 grasses evolved during the early part of the Oligocene, some 14 million years earlier than previously thought. This new evidence casts doubt on the widely-held belief that the rise of this incredibly productive group of plants was driven by a large drop in atmospheric carbon dioxide concentrations during the Oligocene epoch.

C4 plants compose only 3 percent of flowering plant species, yet account for about 25 percent global terrestrial productivity. About 60% of C4 species are grasses, and they dominate the world's grassland and savanna biomes, particularly those in warmer, lower latitude areas. Their ecological success results from the way these species concentrate and then fix carbon dioxide in order to power photosynthesis. link

Born This Day: Sir Charles Lyell

From Minnesota State University at Mankato comes this excellent bio on Lyell:

Sir Charles Lyell (Nov. 14, 1797 - Feb. 22, 1875) attended Oxford University at age 19. Lyell's father was an active naturalist. Lyell had access to an elaborate library including subjects such as Geology.

When Lyell was at Oxford, his interests were mathematics, classics, law and geology. He attended a lecture by William Buckland that triggered his enthusiasm for geology. Lyell originally started his career as a lawyer, but later turned to geology. He became an author of The Geological Evidence of the Antiquity of Man in 1863 and Principles of Geology. Lyell argued in this book that, at the time, presently observable geological processes were adequate to explain geological history. He thought the action of the rain, sea, volcanoes and earthquakes explained the geological history of more ancient times.

Lyell rebelled against the prevailing theories of geology of the time. He thought the theories were biased, based on the interpretation of Genesis. He thought it would be more practical to exclude sudden geological catastrophes to vouch for fossil remains of extinct species and believed it was necessary to create a vast time scale for Earth's history. This concept was called Uniformitarianism. The second edition of Principles of Geology introduced new ideas regarding metamorphic rocks. It described rock changes due to high temperature in sedimentary rocks adjacent to igneous rocks. His third volume dealt with paleontology and stratigraphy. Lyell stressed that the antiquity of human species was far beyond the accepted theories of that time.

Charles Darwin became his dear friend and correspondent. Darwin is quoted saying, "The greatest merit of the Principles was that it altered the whole tone of one's mind, and therefore that, when seeing a thing never seen by Lyell, one yet saw it through his eyes."

Image from King’s College London.

Fantasia Debuts (1940)

Walt Disney’s epic film, Fantasia, opened this day on Broadway in New York City in 1940. The film featured Leopold Stokowski and the Philadelphia Orchestra performing a number of pieces of classical music to the film’s animated visuals. Igor Stravinsky’s “Rite of Spring” provided the score for the evolution of the Earth including a wonderful sequence on the extinction of the dinosaurs at the end of the Cretaceous. Many school teachers actually showed this sequence in science class -- that’s where I first saw it!

Born This Day: Helen Mack

Nov 13, 1913 – August 13, 1986

Helen starred as Helene Peterson in “Son of Kong”, the quickie follow up to “King Kong”. Once again Carl Denham leads a beautiful girl into danger on Skull Island.

Born This Day: Julie Ege

Nov. 12, 1943 – April 29, 2008

Julie had the lead role as Nala in the 1971 Hammer film, “Creatures The World Forgot”.

Died This Day: Gideon Mantell

Mantell (Feb. 3, 1790 – Nov. 10, 1852), a physician of Lewes in Sussex in southern England, had for years been collecting fossils in the sandstone of Tilgate forest, and he had discovered bones belonging to three extinct species: a giant crocodile, a plesiosaur, and Buckland's Megalosaurus. But in 1822 he found several teeth that "possessed characters so remarkable" that they had to have come from a fourth and distinct species of Saurian. After consulting numerous experts, Mantell finally recognized that the teeth bore an uncanny resemblance to the teeth of the living iguana, except that they were twenty times larger.
In this paper, the second published description of a dinosaur, he concluded that he had found the teeth of a giant lizard, which he named Iguanodon, or "Iguana-tooth."

Mantell illustrated his announcement with a single lithographed plate. Mantell included at the bottom of the plate a drawing of a recent iguana jaw, which is shown four times natural size, and for further comparison, he added views of the inner and outer surface of a single iguana tooth, "greatly magnified."

The traditional story that Mantell's wife found the first teeth in 1822, while the doctor was visiting a patient, appears, alas, to be unfounded.

Info and plate from HERE.

Born This Day: Francis Maitland Balfour

Balfour (Nov. 10, 1851 – July 19, 1882) was a British zoologist and a founder of modern embryology. Influenced by the work of Michael Foster, with whom he wrote Elements of Embryology (1883), Balfour showed the evolutionary connection between vertebrates and certain invertebrates (similar to research being done by Aleksandr Kovalevski).

Balfour proposed the term Chordata for all animals possessing a notochord at some stage in their development. He also did pioneer work on the development of the kidneys and related organs, as well as the spinal nervous system. While convalescing from typhoid fever in Switzerland, he died at the young age of 30 from a fall while attempting an ascent of the unconquered Aiguille Blanche of Mont Blanc. From Today In Science History

Died This Day: Alfred Russel Wallace

Wallace (Jan. 8, 1823 – Nov. 7, 1913) was a British naturalist and biogeographer. He was the first westerner to describe some of the most interesting natural habitats in the tropics. He is best known for devising a theory of the origin of species through natural selection made independently of Darwin.

Between 1854 and 1862, Wallace assembled evidence of natural selection in the Malay Archipelago, sending his conclusions to Darwin in England. Their findings were jointly presented to the Linnaean Society in 1858. Wallace found that Australian species were more primitive, in evolutionary terms, than those of Asia, and that this reflected the stage at which the two continents had become separated. He proposed an imaginary line (now known as Wallace's line) dividing the fauna of the two regions.

From Today In Science History

The Alfred Russel Wallace page HERE. More HERE.

Died This Day: Henry Fairfield Osborn

Osborn graduated (August 8, 1857 - November 6, 1935) from Princeton in 1877 and pursued his interest in the biological sciences and paleontology through additional study at several New York City medical schools and with Thomas Henry Huxley in Britain. Returning to the United States, Osborn accepted a position at Princeton, teaching natural sciences from 1881 until 1891, when he moved to Columbia University to organize the Biology Department there, and in 1891, he also helped to organize the Department of Vertebrate Paleontology at the American Museum of Natural History acting as it’s first curator. Osborn's close association with American Museum continued for over 45 years, and included a long tenure as its President, 1908-1933. During these years the museum's collections expanded enormously and it became one of the preeminent research institutions for natural history in the world.

Osborn is noted for describing and naming both Tyrannosaurus rex and Albertosaurus in 1905, Pentaceratops in 1923, and Velociraptor in 1924. One of Osborn's favorite groups for study was the brontotheres, and he was the first to carry out comprehensive research on them. He also wrote an influential textbook, The Age of Mammals (1910).

Apart from his own research, Osborn is perhaps best remembered for the sponsorship of the five immensely successful Central Asiatic Expeditions during the 1920's and 30's led by Roy Chapman Andrews.

Entry from HERE and HERE.

Died This Day: Alfred Sherwood Romer

”Romer (Dec. 28, 1894 – Nov. 5, 1973) was director of the Museum of Comparative Zoology at Harvard University until his retirement in 1961 and was one the singularly most influential vertebrate paleontologists of the 20th Century. His work ranged over virtually every conceivable subject within that field, although it was the osteology and taxonomy of the therapsids and other proto-mammals which was nearest his heart.

In addition to this work, Romer was acutely interested in the origin and initial adaptive radiation of tetrapods, and his work became the basis for a theory of tetrapod origins which was canon until the description of Acanthostega gunnari by Clack & Coates in the 1990s. Romer was ahead of his time in his defense of monophyly of Dinosauria though he did feel that Theropoda was not ancestral to birds.” link from EvoWiki.org

Romer’s book, Vertebrate Paleontology (1966), was for many years THE textbook on VP and is still well worth picking up. One of Romer’s students, Bob Carroll, wrote an updated version entitled, ‘Vertebrate Paleontology and Evolution’, in 1987. image

Born This Day: J.B.S. Haldane

Haldane (Nov. 5, 1892 - Dec. 1, 1964) is best remembered along with E. B. Ford and R. A. Fisher one of the three major figures to develop the mathematical theory of population genetics. His greatest contribution was in a series of ten papers on "A Mathematical Theory of Natural and Artificial Selection" which was the major series of papers on the mathematical theory of natural selection. It treated many major cases for the first time, showing the direction and rates of changes of gene frequencies. It also pioneered in investigating the interaction of natural selection with mutation and with migration.

Haldane's book, The Causes of Evolution (1932), summarized these results, especially in its extensive appendix. This body of work was a component of what came to be known as the "modern evolutionary synthesis", re-establishing natural selection as the premier mechanism of evolution by explaining it in terms of the mathematical consequences of Mendelian genetics. From Wikipedia. More info here.

More On Darwinius

Darwinius masillae is a Haplorhine — Reply to Williams et al. (2010) . 2010. J. of Human Evolution 59: 574-579

A new investigation of the skeleton of Darwinius masillae, known as ‘Ida’, confirms and strengthens earlier conclusions of the team working on the fossil.

Researchers have presented several cladistic analyses reaffirming Darwinius as a haplorhine primate related to anthropoid or higher primates (monkeys and apes). The new study discusses and refutes studies by Seiffert and others (2009) in Nature, and Williams and others (2010) in Journal of Human Evolution that sought to dismiss Darwinius as a strepsirrhine primate (related to lemurs and lorises).

Darwinius is now placed within the anthropoid line of primate evolution. One of the new cladistic analyses was made by excluding fossil taxa consisting only of small fragments like single teeth or jaws. This led to a more robust result with many fewer and more strongly supported cladistic trees.

More on the research and story behind Darwinius masillae.

Thanks to Jorn for sending me the press release.

Early Eocene Amber from India

Biogeographic and evolutionary implications of a diverse paleobiota in amber from the early Eocene of India. 2010. J. Rust, et al. PNAS, Published online before print October 25.

David Grimaldi/AMNH

Bees, termites, spiders, and flies entombed in a newly-excavated amber deposit are challenging the assumption that India was an isolated island-continent in the Early Eocene, or 52-50 million years ago. Arthropods found in the Cambay deposit from western India are not unique—as would be expected on an island—but rather have close evolutionary relationships with fossils from other continents. The amber is also the oldest evidence of a tropical broadleaf rainforest in Asia.

Amber from broadleaf trees is rare in the fossil record until the Tertiary, or after the dinosaurs went extinct. It was during this era that flowering plants rather than conifers began to dominate forests and developed the ecosystem that still straddles the equator today. The new amber, and amber from Colombia that is 10 million years older, indicates that tropical forests are older than previously thought.

The amber has been chemically linked to Dipterocarpaceae, a family of hardwood trees that currently makes up 80 percent of the forest canopy in Southeast Asia. ossilized wood from this family was found as well, making this deposit the earliest record of these plants in India and showing that this family is nearly twice as old as was commonly believed. It most likely originated when portions of the southern supercontinent Gondwana were still connected. link

The Emergence of Modern Humans in East Asia

Human remains from Zhirendong, South China, and modern human emergence in East Asia. 2010. W. Liu, et al. PNAS, Published online before print October 25.



The discovery of early modern human fossil remains in the Zhirendong (Zhiren Cave) in south China that are at least 100,000 years old provides the earliest evidence for the emergence of modern humans in eastern Asia, at least 60,000 years older than the previously known modern humans in the region.

The Zhirendong fossils have a mixture of modern and archaic features that contrasts with earlier modern humans in east Africa and southwest Asia, indicating some degree of human population continuity in Asia with the emergence of modern humans.

The Zhirendong humans indicate that the spread of modern human biology long preceded the cultural and technological innovations of the Upper Paleolithic and that early modern humans co-existed for many tens of millennia with late archaic humans further north and west across Eurasia. link

Philip Currie Receives Alberta Order of Excellence

Philip Currie was invested into the Alberta Order of Excellence in a ceremony in Edmonton on Wednesday, October 20. Congratulations on a well deserved honour!

From the web site:

Dr. Phil Currie is an internationally renowned palaeontologist whose scientific accomplishments have led to a greater understanding of dinosaurs and their historic significance. He was instrumental in the development of Alberta’s Royal Tyrrell Museum and has made major contributions to palaeontology on both the Canadian and the world stage through his extensive field work, academic research, writing and teaching.

Read his full bio here.

Cannibalism in T. rex

Cannibalism in Tyrannosaurus rex. 2010. N. Longrich, et al. PLoS ONE 5(10): e13419



The marks are definitely the result of feeding, although scientists aren’t sure whether they are the result of scavengers or the end result of fighting, Longrich said, adding that if two T. rex fought to the death, the victor might have made a meal out of his adversary. “Modern big carnivores do this all the time,” he said. “It’s a convenient way to take out the competition and get a bit of food at the same time.”

However, the marks appear to have been made some time after death, Longrich said, meaning that if one dinosaur killed another, it might have eaten most of the meat off the more accessible parts of the carcass before returning to pick at the smaller foot and arm bones. link

Born This Day: Constantine Samuel Rafinesque

Rafinesque (Oct 22, 1783 – Sept. 18, 1840) was a naturalist, traveler, and writer who made major and controversial contributions to botany and ichthyology. Rafinesque believed that each variety of a species is a "deviant," which, through reproduction, may become a permanent species; thus, he anticipated, to some extent, part of Charles Darwin's theory of evolution.

Although Rafinesque's scientific abilities were recognized in his lifetime, he was also severely criticized for sometimes doing careless work and for his tendency to establish new genera and species. Throughout his life he traveled extensively, collected specimens wherever he went, and wrote and published constantly. From Today In Science History

Image and more info here.

Died This Day: Sir Roderick Murchison

Murchison (Feb. 19, 1792 - Oct. 22, 1871) was a Scottish geologist who first differentiated the Silurian strata in the geologic sequence of Early Paleozoic strata (408-540 million years old). He believed in fossils as primary criteria. In 1831, he began researching the previously geologically unknown graywacke rocks of the Lower Paleozoic, found underlying the Old Red Sandstone in parts of Wales, which culminated in his major work the Silurian System (1839).

An eurypterid, a prehistoric sea scorpion from PBS.org.

Murchison named the Silurian after an ancient British tribe that inhabited South Wales. He established the Devonian working with Adam Sedgwick (1839). He named the Permian (1841) after the Perm province in Russia where he made a geological survey in 1840-45. link

Evolution of Sexual Organs in Plants

Single amino acid change alters the ability to specify male or female organ identity. 2010. C.A. Airoldi, et al. PNAS, published ahead of print October 18.

The Day of The Triffids in Lego

New research has uncovered a snapshot of evolution in progress, by tracing how a gene mutation over 100 million years ago led flowers to make male and female parts in different ways.

In a number of plants, the gene involved in making male and female organs has duplicated to create two, very similar, copies. In rockcress (Arabidopsis), one copy still makes male and female parts, but the other copy has taken on a completely new role: it makes seed pods shatter open. In snapdragons (Antirrhinum), both genes are still linked to sex organs, but one copy makes mainly female parts, while still retaining a small role in male organs – but the other copy can only make male.

"Snapdragons are on the cusp of splitting the job of making male and female organs between these two genes, a key moment in the evolutionary process," says Brendan Davies.

By tracing back through the evolutionary 'tree' for flowering plants, the researchers calculate the gene duplication took place around 120 million years ago. But the mutation which separates how snapdragons and rock cress use this extra gene happened around 20 million years later.

"Our research is an excellent example of how a chance imperfection sparks evolutionary change. If we lived in a perfect world, it would be a much less interesting one, with no diversity and no chance for new species to develop." link