Stephen Hedges Stephen Blair Hedges (known as S. Blair Hedges) is Laura H. Carnell Professor of Science and director of the Center for

Biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic ('' genetic variability''), species ('' species diversity''), and ecosystem ('' ecosystem diversity' ...

Temple University Temple University (Temple or TU) is a public university, public Commonwealth System of Higher Education, state-related research university in Philadelphia, Pennsylvania. It was founded in 1884 by the Baptists, Baptist minister Russell Conwell an ...

where he researches the

tree of life The tree of life is a fundamental archetype in many of the world's mythological, religious, and philosophical traditions. It is closely related to the concept of the sacred tree.Giovino, Mariana (2007). ''The Assyrian Sacred Tree: A Histo ...

and leads conservation efforts in Haiti and elsewhere. He co-founded

Haiti National Trust Haiti National Trust is an international, non-governmental, and non-profit environmental organization dedicated to protecting the biodiversity of Haiti. The Haiti National Trust seeks to establish more protected areas, including national parks, an ...

Career

Hedges has a

Bachelor of Science A Bachelor of Science (BS, BSc, SB, or ScB; from the Latin ') is a bachelor's degree awarded for programs that generally last three to five years. The first university to admit a student to the degree of Bachelor of Science was the University o ...

undergraduate degree from

George Mason University George Mason University (George Mason, Mason, or GMU) is a public research university in Fairfax County, Virginia with an independent City of Fairfax, Virginia postal address in the Washington, D.C. Metropolitan Area. The university was orig ...

, and a Masters and

Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is a ...

Zoology Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, and ...

from the

University of Maryland The University of Maryland, College Park (University of Maryland, UMD, or simply Maryland) is a public university, public Land-grant university, land-grant research university in College Park, Maryland. Founded in 1856, UMD is the Flagship un ...

, supervised by

Richard Highton Richard Highton (born December 24, 1927) is an American herpetologist, an expert on the biological classification of woodland salamanders. Education and personal life Highton was born in Chicago. His father encouraged his son to have an inte ...

. Before he joined Temple University in 2014, he was a professor at

Penn State #Redirect Pennsylvania State University The Pennsylvania State University (Penn State or PSU) is a public state-related land-grant research university with campuses and facilities throughout Pennsylvania. Founded in 1855 as the Farmers' High ...

. He is also a founding member of the NASA

Astrobiology Astrobiology, and the related field of exobiology, is an interdisciplinary scientific field that studies the origins, early evolution, distribution, and future of life in the universe. Astrobiology is the multidisciplinary field that investi ...

Center. He has published over 300

peer-reviewed Peer review is the evaluation of work by one or more people with similar competencies as the producers of the work ( peers). It functions as a form of self-regulation by qualified members of a profession within the relevant field. Peer revie ...

works including 10 books and monographs. He was elected as a fellow of the

American Association for the Advancement of Science The American Association for the Advancement of Science (AAAS) is an American international non-profit organization with the stated goals of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsi ...

in 2009 for "revealing connections between biological evolution and Earth history in diverse groups of organisms", and was awarded the 2011 Penn State Faculty Scholar Medal for Outstanding Achievement in the Life and Health Sciences. A Cuban butterfly (''Leptodes hedgesi'' Schwartz & Johnson 1992), Cuban frog (''Eleutherodactylus blairhedgesi'' Estrada, Diaz, & Rodriguez 1997), and Cuban millipede (''Amphelictogon blairi'' Perez-Asso 1998) have been named in his honor.

Research

Hedges has studied the relationships and timing of major groups in the tree of life using genomic data. This research has led to a number of discoveries including an early origin for the orders of placental mammals and modern birds, estimates of when

prokaryote A prokaryote () is a single-celled organism that lacks a nucleus and other membrane-bound organelles. The word ''prokaryote'' comes from the Greek πρό (, 'before') and κάρυον (, 'nut' or 'kernel').Campbell, N. "Biology:Concepts & Con ...

s and

eukaryote Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bact ...

s first colonized land and its relevance for the planet, and the

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

relationships of reptiles and

insectivorous A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores were ...

mammals. He has coined the word

timetree TimeTree is a free public database developed by S. Blair Hedges and Sudhir Kumar, now at Temple University, for presenting times of divergence in the tree of life. The basic concept has been to produce and present a community consensus of the tim ...

for a phylogenetic tree scaled to time, co-founded the TimeTree database for exploring the time-scale of the tree of life, and co-edited the book ''Timetree of Life''. Hedges and his team produced a spiral

in 2015 to visualize the relationships over time of 50,000 species, and discovered that diversification and

speciation Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution withi ...

are both relatively constant through time and among groups. Hedges also has a field program in the Caribbean where he has studied the evolution and biogeography of amphibians and reptiles with genetic data and maintained a database of information on these species,

Caribherp Caribherp is an online database containing information on amphibians and reptiles of the Caribbean Islands. It was established in 1999 and serves as a resource for determining the species that occur on specific islands, viewing their distributio ...

. He discovered many new species in his work and has so far named 135 species of reptiles, amphibians, and butterflies. He also described three of the smallest species of reptiles and amphibians, including the Monte Iberia dwarf frog (''Eleutherodactylus iberia''), Jaragua gecko (''

Sphaerodactylus ariasae ''Sphaerodactylus ariasae'', commonly called the Jaragua sphaero or the Jaragua dwarf gecko, is the smallest species of lizard in the family Sphaerodactylidae. Description ''Sphaerodactylus ariasae'' is the world's smallest known reptile. Th ...

''), and the

Barbados threadsnake The Barbados threadsnake (''Tetracheilostoma carlae'') is a species of threadsnake. It is the smallest known snake species. This member of the Leptotyphlopidae family is found on the Caribbean islands of Barbados and Anguilla. Taxonomy and e ...

(''Tetracheilostoma carlae''). Twelve articles in the ''

New York Times ''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid ...

'' have described his research.

Conservation

Work by Hedges and his team in Haiti has defined hot spots of biodiversity leading to the establishment of three national parks in Haiti. He also initiated a

captive breeding Captive breeding, also known as captive propagation, is the process of plants or animals in controlled environments, such as wildlife reserves, zoos, botanic gardens, and other conservation facilities. It is sometimes employed to help species t ...

program to conserve ten endangered species of frog at the

Philadelphia Zoo The Philadelphia Zoo, located in the Centennial District of Philadelphia on the west bank of the Schuylkill River, is the first true zoo in the United States. It was chartered by the Commonwealth of Pennsylvania on March 21, 1859, but its openi ...

. Together with Haitian CEO

Philippe Bayard Philippe is a masculine sometimes feminin given name, cognate to Philip. It may refer to: * Philippe of Belgium (born 1960), King of the Belgians (2013–present) * Philippe (footballer) (born 2000), Brazilian footballer * Prince Philippe, Count ...

, he founded

, an environmental protection

NGO A non-governmental organization (NGO) or non-governmental organisation (see spelling differences) is an organization that generally is formed independent from government. They are typically nonprofit entities, and many of them are active in ...

Personal life

Hedges is interested in

Renaissance art Renaissance art (1350 – 1620 AD) is the painting, sculpture, and decorative arts of the period of European history known as the Renaissance, which emerged as a distinct style in Italy in about AD 1400, in parallel with developments which occ ...

, which led him to conduct several scientific studies of early artwork, including the development of a method for dating old prints and a study on the historical biogeography of beetles based on the holes they bored in old books.

References

External links

* {{DEFAULTSORT:Hedges, S. Blair Living people Evolutionary biologists Pennsylvania State University faculty Temple University faculty American herpetologists George Mason University alumni University of Maryland, College Park alumni Fellows of the American Association for the Advancement of Science Year of birth missing (living people) Place of birth missing (living people)