Wednesday, May 28, 2014

Born This Day: Louis Agassiz

(Jean) Louis (Rodolphe) Agassiz (May 28, 1807 - Dec. 14, 1873) was a Swiss-born U.S. naturalist, geologist, and teacher who made revolutionary contributions to the study of natural science with landmark work on glacier activity and extinct fishes. Agassiz began his work in Europe, having studied at the University of Munich and then as chair in natural history in Neuchatel in Switzerland. While there he published his landmark multi-volume description and classification of fossil fish.

In 1846 Agassiz came to the U.S. to lecture before Boston's Lowell Institute. Offered a professorship of Zoology and Geology at Harvard in 1848, he decided to stay, becoming a citizen in 1861. His innovative teaching methods altered the character of natural science education in the U.S. Link

More info HERE

Wednesday, May 21, 2014

Born This Day: Mary Anning

Mary Anning (May 21, 1799 - March 9, 1847)was an English fossil collector who made her first significant discovery at the age of 11 or 12 (sources differ on the details), when she found a complete skeleton of an Ichthyosaurus, from the Jurassic period. The ten-meter (30 feet) long skeleton created a sensation and made her famous.

Anning's determination and keen scientific interest in fossils derived from her father's interest in fossil hunting, and a need for the income derived from them to support her family after his death. in 1810. She sold large fossils to noted paleontologists of the day, and smaller ones to the tourist trade. In 1823, Anning made another great discovery, found the first complete Plesiosaurus.

Later in her life, the Geological Society of London granted Anning an honorary membership.

Wednesday, May 07, 2014

The Evolution of Living Dinosaurs

Rates of Dinosaur Body Mass Evolution Indicate 170 Million Years of Sustained Ecological Innovation on the Avian Stem Lineage . 2014. Benson, et al. PLoS Biol 12(5): e1001853.

An international team estimated the body mass of 426 dinosaur species based on the thickness of their leg bones. The team found that dinosaurs showed rapid rates of body size evolution shortly after their origins, around 220 million years ago. However, these soon slowed: only the evolutionary line leading to birds continued to change size at this rate, and continued to do so for 170 million years, producing new ecological diversity not seen in other dinosaurs. Press release

Monday, May 05, 2014

Born This Day: Elkanah Billings

From Today In Science History:

Billings (May 5, 1820 - June 14, 1896) was a Canadian geologist and paleontologist, who was the first Canadian paleontologist.He published his first scientific paper on Trenton fossils in 1854. He launched a new monthly periodical, The Canadian Naturalist and Geologist in 1856, which he also edited and was the major contributor.

In Aug 1856 he was appointed staff paleontologist with the Canadian Geological Survey by William Edmond Logan, the founder of the Survey. Billings immediately began the task of identifying a 20-year backlog of fossils collected by the Survey. By 1863 he had published descriptions of no fewer than 526 new species of fossils.

The Billings medal, named in his honour, is awarded annually by the Paleontology Division of the Geological Association of Canada as a means of recognizing the most outstanding of its paleontologists.
On April 27, 1869, the Director of the GSC, Sir William Logan wrote this curt note to the paleontologist Elkanah Billings: "Your constant absence from the office is a worrying annoyance, particularly as I have reason to suspect that it does not arrive from rheumatism".
For more info on Billings click HERE.

Click HERE for more information on the Geological Association of Canada.

Portrait of Elkanah Billings GSC photo 69323 (c)

Sunday, May 04, 2014

From the UC Berkeley Page:

Huxley (May, 4, 1825 - June 29, 1895) was born in Ealing, near London, the seventh of eight children in a family that was none too affluent. At 21, Huxley signed on as assistant surgeon on the H.M.S. Rattlesnake, a Royal Navy frigate assigned to chart the seas around Australia and New Guinea. Huxley collected and studied marine invertebrates, in particular cnidarians, tunicates, and cephalopod mollusks. After leaving the Navy in 1854, Huxley managed to secure a lectureship at the School of Mines in London.

Huxley was a passionate defender of Darwin's theory -- so passionate that he has been called "Darwin's Bulldog" – and also a great biologist in his own right, who did original research in zoology and paleontology.

He is best known for his famous debate in June 1860, at the British Association meeting at Oxford. His opponent, Archbishop Samuel Wilberforce, was not-so-affectionately known as "Soapy Sam" for his renowned slipperiness in debate. During the debate, Archbishop Wilberforce ridiculed evolution and asked Huxley whether he was descended from an ape on his grandmother's side or his grandfather's. Accounts vary as to exactly what happened next, but according to one telling of the story, Huxley muttered "The Lord hath delivered him into my hands," and then rose to give a brilliant defense of Darwin's theory, concluding with the rejoinder, "I would rather be the offspring of two apes than be a man and afraid to face the truth."

All accounts agree that Huxley trounced Wilberforce in the debate, defending evolution as the best explanation yet advanced for species diversity.

However, Huxley did not blindly follow Darwin's theory, and critiqued it even as he was defending it. In particular, where Darwin had seen evolution and a slow, gradual, continuous process, Huxley thought that an evolving lineage might make rapid jumps, or saltations. As he wrote to Darwin just before publication of the Origin of Species, "You have loaded yourself with an unnecessary difficulty in adopting Natura non facit saltum [Nature does not make leaps] so unreservedly."

Huxley's most famous writing, published in 1863, is Evidence on Man's Place in Nature. This book, published only five years after Darwin's Origin of Species, was a comprehensive review of what was known at the time about primate and human paleontology and ethology. More than that, it was the first attempt to apply evolution explicitly to the human race. Huxley explicitly presented evidence for human evolution.

Huxley founded a remarkable dynasty of English scientists and thinkers. His son Leonard was a noted biographer and "man of letters." Leonard's oldest son Julian was one of the authors of the evolutionary synthesis of the early 20th century; Julian's son Francis became a noted anthropologist. Julian's brother Aldous Huxley was a novelist, screenwriter and essayist; his best-known book is the anti-utopia Brave New World.

Friday, May 02, 2014

Born This Day: Sir D'Arcy Thompson


D'Arcy Thompson (May 2, 1860 – June 21, 1948) was a British biologist whose masterwork, On Growth and Form, is a profound consideration of the shapes of living things, starting from the simple premise that "everything is the way it is because it got that way." Hence one must study not only finished forms, but also the forces that moulded them: "the form of an object is a 'diagram of forces', in this sense, at least, that from it we can judge of or deduce the forces that are acting or have acted upon it."

Now by "forces" Thompson meant forces, and one of his great themes is the tremendous light cast on living things by using mathematics to describe their shapes and fairly simple physics and chemistry to explain them. In other words, Thompson wrote a thousand page treatise on self-organization long before the word existed.
From Blackwell Publishing:
D'Arcy Thompson found that related species superficially looking very different could in some cases be represented as simple Cartesian transformations of one another. The most thoroughly worked out modern example of this is Raup's analysis of snail shell shapes with a morphospace.

With some simplification, the axes on the fish grids in here or the snails of the morphospace can be thought of as growth gradients. The evolutionary change between the species would then have been produced by a genetic change in the regulatory mechanisms controlling those gradients.

If we looked at these fish without the grids we might think that an evolutionary change from one into the other would be at least moderately complicated. The interest of D'Arcy Thompson's diagrams is then to show that shape changes could have been produced by heterochrony - a change in the rate or timing of development of some cell lines in the body relative to others.

Figure: a D'Arcy Thompson transformational diagram. The shapes of two species of fish have been plotted on Cartesian grids. Image from HERE.