Rudolf Leuckart

Karl Georg Friedrich Rudolf Leuckart was born on October 7, 1822 in Helmstedt, Lower Saxony, which would later become part of Germany. His father owned a printing plant and his uncle, Friedrich Sigismund Leuckart, was a professor of zoology. His uncle awakened the interest in zoology in his young nephew, who collected insects. Leuckart was interested in pursuing a career in zoology, but a the time there were no university programs devoted to it, so he was forced to study medicine, which he did at the University of Gottingen starting in 1842. At Gottingen Leuckart met zoologist Rudolf Wagner and became his assistant in 1845. Leuckart's dissertation, the same year, won a university prize. Leuckard became a zoology lecturer and in 1848 he went on his first expedition to the North Sea to study marine microorganisms.

In 1850 Leuckart became professor of zoology at the University of Giessen. The years at Giessen were productive for Leuckart and he did a lot of the work studying parasites. He proved that cattle were the carrier of beef tape worm (Taenia saginata) and that pigs were the carriers of pork tapeworm (Taenia solium). Most vertebrate species have a tapeworm species that has evolved to live in its intestines. His studies of Trichina, the cause of trichinosis was used by Rudolf Virchow's campaign for meat inspection laws in Germany. With Virchow and Friedrich Albert von Zenker, he was the first to document the life cycle of Trichnella spiralis. For his work on parasites Leuckart is known as the father of parasitology. He also studied insects, documenting the anatomy and life cycle of the honey bee and the life cycle of Hippoboscoidea, (called Pupipara at the time) a super-family of obligate blood parasites that includes tsetse flies and bat flies.

In 1861 he was named a privy councilor by the King of Saxony and was awarded an honorary PhD by University of Giessen. In 1869 he moved to the University of Leipzig. At first the facilities were inadequate, but in 1880 a zoological institute was built according to his specifications. It quickly became a center for zoological learning and attracted students from around the world. While at Giessen he created a series of zoological posters showing  species of invertebrates that have been used world wide as teaching aids. Leuckart's magnum opus, a two volume work on human parasites and the diseases they cause remained unfinished at the time of his death but was still widely used by students of parisitology.

 Leuckart died in Leipzig on February 6, 1898.


References:

Kellog, Vernon L.;"Rudolf Leuckart"; Psyche (1898)8:214-215

"Leuckart, Karl Friedrich Rudolph"; in The Complete Dictionary of Scientific Biography; Charles Scribner's Sons; 2008

Rudolph Leuckart Wikipedia Entry

August Weismann

Friedrich Leopold August Weismann was born on January 17, 1834 in Frankurt, Germany. His father was a high school teacher and graduate in ancient languages and theology. His early education took place in Frankfurt and at 18 he left to go to the University of Gottingen where he studied medicine, graduating in 1856. After graduation he took a job in the city clinic in Rostock and successfully submitted two papers, one on the synthesis of hippuric acid in herbivores and one on the salt content of the Baltic Sea. He served as the physician of the Archduke of Austria from 1860 to 1862.

He studied zoology at the University of Giessen under Rudolf Leuckart and in 1863 he became privadozent in comparative anatomy at the Albert Ludwig University of Freiburg in Breisgau. He was made extraordinary professor in 1866 and was full professor from 1873 to 1912. He was the first chair in zoology and served as director of the zoological institute. Due to problems with his eyesight there were long periods in which he was unable to do microscope work and his reading and writing was done with the help of others.

Weismann's biological studies led him to theorize that in multicellular organisms there were two type of cells, germ cells and soma cells. Germ cells, such as sperm or ova, are the carriers of biological information, the means by which traits of parent cells were transferred to daughter cells. Somatic cells were the offspring of germ cells and carried out the biological functions of the organism. These somatic cells did not transfer information to future generations. Before the discovery that chromosomes are the means that cells use to transfer genetic information, Weismann's germ cell theory was an important stepping stone, holding that biological traits come from within the organism and do not arise from an external mechanism.

For his work Weismann was awarded the Linnean Society of London's Darwin-Wallace medal in 1908. Weismann died on November 15, 1914.


References:

"August Weisman" in Report of the National Academy of Sciences; U. S. Government Printing Offices; 1914

August Weisman Wikipedia entry

Konrad Zacarias Lorenz

Konrad Zacarias Lorenz was born on November 7, 1903 in Altenberg, Vienna, the son of an orthopedic surgeon. His parents had a large house and garden which allowed him to keep many animals. In an autobiography he says, "they were supremely tolerant of my inordinate love for animals." His study of animals started at a young age and he became an expert on the behaviour of ducks. His first exposure to evolution came from his reading, but in school, even though he studied under a Benedictine Monk he learned about Darwin's theory of evolution, free thought being a characteristic of Austria. His interest in the study of evolution led him to study paleontology as a means of understanding evolution.

After high school, following his father's wishes he took pre-medical school classes at Columbia University. He stayed at Columbia for a year before returning to Vienna where he continued his medical studies at the University of Vienna, finishing his MD in 1928. In medical school his anatomy professor was Ferdinand Hoschsetter, and under his teaching Lorenz began to study comparative anatomy, which he soon realized was a better way to study evolution than paleontology. After graduation, instead of practicing medicine Lorenz continued his studies in comparative anatomy, supporting himself by taking a position at the university as an assistant in the Institute of Anatomy, which he retained until 1935. In 1933 he finished his Ph.D. in comparative anatomy. Throughout he kept studying the birds on his parents estate.

In 1936 Lorenz met Nikolaas Tinbergen at a conference in Leiden, Holland. Lorenz found that their studies had much in common and he invited Tinbergen to come to work with him at his parents estate. With Tinbergen, he conducted experiments using the birds on his parent's estate. In these studies they compared the behavior of the wild, domestic and hybrid geese. They showed that domesticated geese had an increased drive for feeding and copulation, but showed a decrease in socialization. Soon after came the Anchluss, the German annexation of Austria, and Lorenz wrote about the differences of domesticated species using terms of Nazi ideology. These allowed Lorenz to be appointed the chair in psychology at Koningsberg. Lorenz later recanted these writings. During the World War II Lorenz served as a physician on the German side, until he was captured by the Russians, after which he was a prisoner of war, serving the medical needs of the Russian army.

After being released by the Russians, Lorenz returned to Altenberg. Unable to obtain an academic position, with the aid of donations and his students he continued his animal research there concentrating again on water fowl and fish. He made a study of the bonding of water fowl and aggressiveness of fish. Even after years of watching animals he found there were new insights and published more papers describing these behaviours. In 1950 the Max Planck Society established the Lorenz Institute for Behavioural Physiology in Buldern, Germany.

In 1973 Lorenz, Tinbergen, and Karl Von Frisch won the Nobel Prize for Physiology and Medicine for "their discoveries concerning organization and elucidation of individual and social behavior patterns". They were awarded the prize for developing the science of ethology. Ethology is the study of animal behavior with regard to evolution. Where a psycologist will study the behavoir of an animal in a laboratory, out of the animals native environment, an ethologist studies behavior in the environment. Studying how evolution has affected an animal's behavior.

Lorenz died on February 27, 1989.


References:

Fuller, Ray; Seven Pioneers of Psychology: Behaviour and Mind
; Psychology Press; 1995

Lorenz, Konrad, Nobel Autobiography

Lorenz, Konrad Wikipedia Entry

Thomas Say

Thomas Say was born in Philadelphia, Pennsylvania on June 27, 1787 the son of Benjamin Say, a physician and former state senator, and Ann Bonsal, the granddaughter of botanist John Bartram. Say's ancestors on his father's side had been in Pennsylvania since its founding. Say's mother died during the yellow fever epidemic of 1793 along with his sister Polly. In May 1799, when Say was 12 he was one of the first pupils to attend the Westtown Boarding School, a newly established Quaker school. After finishing school (at 15 as was the custom at the time) Say helped his father in his apothecary business, and was eventually joined by John Speakman, to found Speakman and Say, an apothecary. It was Speakman who ran the business because Say was often distracted by the pursuit of insect and butterfly specimens. Due to his distraction from the business the apothecary failed.


A self taught naturalist, Say as a boy collected specimens for his great-uncle William Bartram. In 1812 he became a charter member and founder of the Academy of Natural Sciences of Philadelphia. Say lived in the rooms of the academy, sleeping underneath the skeleton of a horse. During the War of 1812, say briefly served as a private in the First City Troop. Say only served for slightly over three months in federal service, as the Troop was released from federal service at the end of the war, although Say remained a member.


In 1817 the Academy began publication of a journal, to which Say was a member of the publication committee and a frequent contributor. In 1818 Say joined an expedition to Georgia and Florida (a Spanish possession at the time) several other members of the Academy. The expedition was forced to return home for fear of attacks from native Americans. In 1819-20 Say served as zoologist for Major Stephen Harriman Long's expedition to the Rocky Mountains and and the tributaries to the Missouri River, and in 1823 Say again served as zoologist for Long's expedition to the headwaters of the Mississippi River.


In 1825 Say moved to New Harmony, Indiana at the urging of his friend and patron of the Academy William MacLure. Say, not a member Robert Owen's communistic community in New Harmony, lived as a hermit, collecting specimens and making notes. In New Harmony Say married Lucy Way Sistare, an artist and illustrator and later the first female member of the Academy. With Sistare's help Say was able to complete three volumes on the insects of America and six on the shellfish of North America.


During his career Say described over 1000 beetles and three hundred other insects. For his work he is called the "Father of American Entomology" and he has several species have been named after him.


Say died on October 10, 1834 in New Harmony.

References:

Coates, Benjamin H.; A Biographical Sketch of Thomas Say Esc.; Academy of Natural Sciences of Philadelphia Press; 1835

Weiss, Harry B. and Ziegler, Grace M.; Thomas Say, Early American Naturalist; Ayer Publishing; 1978

Thomas Say, Wikipedia Entry