Mary Higby Schweitzer
Encyclopedia
Mary Higby Schweitzer is a paleontologist at North Carolina State University
known for leading the groups which discovered the remains of blood cells in dinosaur fossils and later discovered soft tissue remains in the Tyrannosaurus rex
specimen MOR 1125, as well as evidence that the specimen was a pregnant female when she died. More recently, Schweitzer's work has shown molecular similarities in Tyrannosaurus remains and chickens, providing further evidence of the bird-dinosaur connection.
from Utah State University
in 1977, and got a Certificate of Secondary Education in Broadfield Science from Montana State University
in 1988. She received her Ph.D., in Biology
from Montana State University in 1995. She has three children. Schweitzer is a devout Christian who believes strongly in the synergy of the Christian faith and the truth of empirical science.
Schweitzer is currently researching Molecular Paleontology
, molecular diagenesis
and taphonomy
, evolution
of physiological and reproductive strategies in dinosaurs and their bird descendants, and astrobiology
. She is also working with NASA
scientists to look for trace evidences of past life on other bodies in the solar system.
s from a 68 million year old fossil bone. The soft tissues are collagen
, a connective protein
. Amino acid sequencing
of several samples have shown matches with the known collagens of chicken
s, frog
s, newt
s and other animals. Prior to Schweitzer’s discovery, the oldest soft tissue recovered from a fossil was less than one million years old. Schweitzer has also isolated organic compounds and antigenic structures
in sauropod egg shells. With respect to the significance of her work, Kevin Padian
, Curator of Paleontology
, University of California Museum of Paleontology
, has stated "Chemicals that might degrade in a laboratory over a short period need not do so in a protected natural chemical environment...it's time to readjust our thinking."
Schweitzer first publicly announced her discovery in 1993.
Since then, the claim of discovering soft tissues in a 68 million year old fossil has been disputed by some molecular biologists. The authenticity of her discovery, however, is now generally not accepted in the scientific community. Newer research, published in PloS One (30 July 2008), has challenged the claims that the material found is the soft tissue of Tyrannosaurus. Thomas Kaye of the University of Washington and his co-authors contend that what was really inside the tyrannosaur bone was slimy biofilm created by bacteria that coated the voids once occupied by blood vessels and cells. The researchers assumed that what previously had been identified as remnants of blood cells, because of the presence of iron, were actually framboids, microscopic mineral spheres bearing iron. They found similar spheres in a variety of other fossils from various periods, including an ammonite. In the ammonite they found the spheres in a place where the iron they contain could not have had any relationship to the presence of blood. The successful extraction of ancient DNA from dinosaur fossils has been reported on two separate occasions, but, upon further inspection and peer review, neither of these reports could be confirmed. A more recent study (October 2010) published in PloS One contradicts the conclusion of Kaye and supports Schweitzer's original conclusion.
North Carolina State University
North Carolina State University at Raleigh is a public, coeducational, extensive research university located in Raleigh, North Carolina, United States. Commonly known as NC State, the university is part of the University of North Carolina system and is a land, sea, and space grant institution...
known for leading the groups which discovered the remains of blood cells in dinosaur fossils and later discovered soft tissue remains in the Tyrannosaurus rex
Tyrannosaurus
Tyrannosaurus meaning "tyrant," and sauros meaning "lizard") is a genus of coelurosaurian theropod dinosaur. The species Tyrannosaurus rex , commonly abbreviated to T. rex, is a fixture in popular culture. It lived throughout what is now western North America, with a much wider range than other...
specimen MOR 1125, as well as evidence that the specimen was a pregnant female when she died. More recently, Schweitzer's work has shown molecular similarities in Tyrannosaurus remains and chickens, providing further evidence of the bird-dinosaur connection.
Biography
Schweitzer earned a B.S. in Communicative DisordersCommunicative Disorders Assistant
A communicative disorders assistant performs hearing and speech-language screenings, prepares therapy materials, implements speech therapy, reports on therapy outcomes, performs routine maintenance on clinical equipment, and works with speech-language pathologists and audiologists to adjust...
from Utah State University
Utah State University
Utah State University is a public university located in Logan, Utah. It is a land-grant and space-grant institution and is accredited by the Northwest Commission on Colleges and Universities....
in 1977, and got a Certificate of Secondary Education in Broadfield Science from Montana State University
Montana State University - Bozeman
Montana State University – Bozeman is a public university located in Bozeman, Montana. It is the state's land-grant university and primary campus in the Montana State University System, which is part of the Montana University System...
in 1988. She received her Ph.D., in Biology
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...
from Montana State University in 1995. She has three children. Schweitzer is a devout Christian who believes strongly in the synergy of the Christian faith and the truth of empirical science.
Schweitzer is currently researching Molecular Paleontology
Paleontology
Paleontology "old, ancient", ὄν, ὀντ- "being, creature", and λόγος "speech, thought") is the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments...
, molecular diagenesis
Diagenesis
In geology and oceanography, diagenesis is any chemical, physical, or biological change undergone by a sediment after its initial deposition and during and after its lithification, exclusive of surface alteration and metamorphism. These changes happen at relatively low temperatures and pressures...
and taphonomy
Taphonomy
Taphonomy is the study of decaying organisms over time and how they become fossilized . The term taphonomy was introduced to paleontology in 1940 by Russian scientist Ivan Efremov to describe the study of the transition of remains, parts, or products of organisms, from the biosphere, to the...
, evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
of physiological and reproductive strategies in dinosaurs and their bird descendants, and astrobiology
Astrobiology
Astrobiology is the study of the origin, evolution, distribution, and future of life in the universe. This interdisciplinary field encompasses the search for habitable environments in our Solar System and habitable planets outside our Solar System, the search for evidence of prebiotic chemistry,...
. She is also working with NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
scientists to look for trace evidences of past life on other bodies in the solar system.
Discoveries
Schweitzer was the first researcher to identify and isolate soft tissueSoft tissue
In anatomy, the term soft tissue refers to tissues that connect, support, or surround other structures and organs of the body, not being bone. Soft tissue includes tendons, ligaments, fascia, skin, fibrous tissues, fat, and synovial membranes , and muscles, nerves and blood vessels .It is sometimes...
s from a 68 million year old fossil bone. The soft tissues are collagen
Collagen
Collagen is a group of naturally occurring proteins found in animals, especially in the flesh and connective tissues of mammals. It is the main component of connective tissue, and is the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content...
, a connective protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
. Amino acid sequencing
Protein sequencing
Protein sequencing is a technique to determine the amino acid sequence of a protein, as well as which conformation the protein adopts and the extent to which it is complexed with any non-peptide molecules...
of several samples have shown matches with the known collagens of chicken
Chicken
The chicken is a domesticated fowl, a subspecies of the Red Junglefowl. As one of the most common and widespread domestic animals, and with a population of more than 24 billion in 2003, there are more chickens in the world than any other species of bird...
s, frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
s, newt
Newt
A newt is an aquatic amphibian of the family Salamandridae, although not all aquatic salamanders are considered newts. Newts are classified in the subfamily Pleurodelinae of the family Salamandridae, and are found in North America, Europe and Asia...
s and other animals. Prior to Schweitzer’s discovery, the oldest soft tissue recovered from a fossil was less than one million years old. Schweitzer has also isolated organic compounds and antigenic structures
Antigen
An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...
in sauropod egg shells. With respect to the significance of her work, Kevin Padian
Kevin Padian
Kevin Padian is a Professor of Integrative Biology at the University of California, Berkeley, Curator of Paleontology, University of California Museum of Paleontology and President of the National Center for Science Education. Padian's area of interest is in vertebrate evolution, especially the...
, Curator of Paleontology
Paleontology
Paleontology "old, ancient", ὄν, ὀντ- "being, creature", and λόγος "speech, thought") is the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments...
, University of California Museum of Paleontology
University of California Museum of Paleontology
The University of California Museum of Paleontology is a paleontology museum located on the campus of the University of California, Berkeley....
, has stated "Chemicals that might degrade in a laboratory over a short period need not do so in a protected natural chemical environment...it's time to readjust our thinking."
Schweitzer first publicly announced her discovery in 1993.
Since then, the claim of discovering soft tissues in a 68 million year old fossil has been disputed by some molecular biologists. The authenticity of her discovery, however, is now generally not accepted in the scientific community. Newer research, published in PloS One (30 July 2008), has challenged the claims that the material found is the soft tissue of Tyrannosaurus. Thomas Kaye of the University of Washington and his co-authors contend that what was really inside the tyrannosaur bone was slimy biofilm created by bacteria that coated the voids once occupied by blood vessels and cells. The researchers assumed that what previously had been identified as remnants of blood cells, because of the presence of iron, were actually framboids, microscopic mineral spheres bearing iron. They found similar spheres in a variety of other fossils from various periods, including an ammonite. In the ammonite they found the spheres in a place where the iron they contain could not have had any relationship to the presence of blood. The successful extraction of ancient DNA from dinosaur fossils has been reported on two separate occasions, but, upon further inspection and peer review, neither of these reports could be confirmed. A more recent study (October 2010) published in PloS One contradicts the conclusion of Kaye and supports Schweitzer's original conclusion.
External links
- Barry Yeoman, Schweitzer's Dangerous Discovery, Discover.
- North Carolina State UniversityNorth Carolina State UniversityNorth Carolina State University at Raleigh is a public, coeducational, extensive research university located in Raleigh, North Carolina, United States. Commonly known as NC State, the university is part of the University of North Carolina system and is a land, sea, and space grant institution...
Faculty Page