The Committee on the International Prize for Biology
the 2002 International Prize for Biology in the field of "Biology of
Dr. Masatoshi Nei, Pennsylvania State University, USA
On September 17, 2002, the Committee on the International Prize for
Biology (chaired by Dr. Saburo Nagakura, President of the Japan
Academy) decided, based on the recommendation of the Prizefs
Selection Committee, to present the 2002 International Prize for
Biology to Dr. Masatoshi Nei, Professor, Pennsylvania State
University, USA. The field of specialization for the 2002 Prize is gBiology
Process of Selection
The Selection Committee, composed of a chairman (Dr. Kunio
Iwatsuki, Professor, The University of the Air) and 18 other
members, including four foreign members, functioned as a
sub-committee of the Committee on the International Prize for
Biology. It sent out invitations for candidate nominations to
academic institutions/associations and individual experts both at
home and abroad in the subject field of specialization. Altogether
these comprised 1,787 mailing addressees. Fifty-one nominations were
received by the deadline. After adjustment for overlapping
nominations, there were nominations for 37 individuals who reside in
14 countries spread throughout the world. Upon careful deliberation
of the nominees at its first through fourth meetings, the Selection
Committee decided to recommend Dr. Nei as the nominee for the 2002
Prize. Thereafter, the Committee on the International Prize for
Biology formally endorsed the Selection Committeefs recommendation.
Achievements Recognized by the Award
Dr. Masatoshi Nei has contributed immensely to laying the
theoretical foundations of current molecular evolutionary biology.
The award recognizes these distinguished contributions, which arise
from his original work in developing many innovative statistical
techniques for the study of genetic diversity in populations and
evolutionary relationships among species at the molecular level,
including methods for estimating the times of divergence of
different species and detecting gene regions in which natural
selection is operating.
In a career spanning more than forty years, working with many
collaborators, Dr. Nei has developed various statistical methods to
determine the molecular mechanisms of biological diversity and
evolution; he has also elaborated the underlying theory and applied
these methods to the analysis of actual data.
One of the best-known statistical methods developed by Dr. Nei
defines the degree of genetic difference between populations and
estimates this ggenetic distanceh from molecular data on DNA and
protein molecules. This measure makes it possible to estimate the
origins of populations and the times of their divergence from common
ancestors utilizing molecular data; known as gNeifs genetic
distance,h it is still in frequent use around the world. Dr. Nei
himself applied it to human populations and obtained the first
evidence pointing to the African origins of modern humans.
In his research on mathematical modeling of DNA evolution, Dr. Nei
devised several statistical methods for estimating the number of
synonymous and nonsynonymous nucleotide substitutions. By applying
these methods to the major histocompatibility complex (MHC) genes,
which are involved in immune responses such as the rejection of
transplanted organs, he then demonstrated that they make it possible
to identify gene regions in which natural selection operates
strongly. These methods continue to be used by a large number of
Dr. Nei further discovered that the puzzling diversity of the MHC
genes in human populations is due to a special pattern of DNA
evolution that occurs when genes protect their hosts from invaders
such as viruses and bacteria.
Dr. Nei has also constructed a mathematical theory of the
phylogenetic relationships of genes using molecular data. With one
of his graduate students, he developed a technique of inferring
molecular phylogenies known as gthe neighbor-joining method,h
which has become the most widely used method of constructing
Through these achievements, which laid the foundations for the
theoretical framework of current molecular evolutionary biology, Dr.
Nei has contributed enormously to the development not only of his
own field, but of every branch of biology that is concerned with
diversity and evolution.
Ceremony and Commemorative Symposium
The presentation ceremony for the 2002 International Prize will
be convened on Monday, December 2, 2002 at the Japan Academy, Tokyo;
and a commemorative international symposium will be held on December
3-4 at Plaza HEISEI in Tokyo.
Committee on the International Prize for Biology
Japan Society for the Promotion of Science
6 Ichiban-cho, Chiyoda-ku, Tokyo 102-8471
Telephone: +81-3-3263-1722, Facsimile: +81-3-3221-2470
Curriculum Vitae of Professor Masatoshi Nei, Receipt of the 2002
International Prize for Biology
|Date of Birth:
||January 2, 1931
||Evan Pugh Professor of Biology, Pennsylvania State
University, University Park
||Institute of Molecular Evolutionary Genetics
Pennsylvania State University
328 Mueller Lab
University Park, PA 16802
|Education and Career:
||B.S. from Miyazaki University, Miyazaki, Japan
||Ph.D. from Kyoto University, Japan
||Assistant Professor, Kyoto University, Japan
||Rockefeller Fellow, University of California and
North Carolina State University
||Geneticist, National Institute of Radiological
Sciences, Chiba, Japan
||Associate Professor to Professor of Biology, Brown
||Professor of Population Genetics, University of
Texas at Houston
||Distinguished Professor of Biology, Pennsylvania
State University, University Park
||Director, Institute of Molecular Evolutionary
Genetic, Pennsylvania State University, University Park
||Evan Pugh Professor of Biology, Pennsylvania State
University, University Park
|Awards and Distinctions:
||Japan Society of Human Genetics Award
||Honorary Member, Genetics Society of Japan
||Fellow, American Academy of Arts and Sciences
||Kihara Prize, Genetics Society of Japan
||Fellow, American Association for the Advancement of Science
||Honorary Member, Japan Society of Human Genetics
||Member, National Academy of Sciences, USA
||Honorary Member, Japan Society for Histocompatibility and
Dr. Masatoshi Nei is one of the main architects who laid the
theoretical foundations of current molecular evolutionary biology. By
developing various statistical methods and applying them to molecular
data, he pioneered new ways of studying the genetic diversity of
populations, evolutionary relationships among organisms, the times of
species divergence from common ancestors, the location of gene regions
in which natural selection is operating, and related areas. The methods
he introduced have made it possible to obtain quantitative estimates of
various parameters of evolutionary importance that could not have been
measured experimentally. Through these achievements, Dr. Nei has not
only made the latest findings at the molecular level available to
evolutionary biologists, but has contributed greatly to the birth of
molecular evolutionary biology and its establishment as a positive
science in which hypotheses can be verified quantitatively, rather than
being discussed solely on a conceptual level.
Evolutionary Histories of Populations and Genetic Distance
One of the best-known statistical methods developed by Dr. Nei is
concerned with defining the degree of genetic difference between
populations and estimating this ggenetic distanceh from protein and
DNA data. Dr. Neifs method, which he proposed in 1972, uses
polymorphism data (individual differences in proteins and DNA) to
estimate the origins of human and other populations, the times at which
they diverged from common ancestral forms, and so on. Under the name gNeifs
genetic distance,h it has been adopted worldwide by most researchers in
related fields and is still frequently used today.
In 1974, Dr. Nei applied his new measure to human populations and showed
that the genetic variation among Europeans, Asians, and Africans is only
about 10 percent of the average variation within the three major human
ethnic groups; he also estimated that Africans diverged from Europeans
and Asians about 100,000 years ago, and Europeans and Asians diverged
from each other about 50,000 years ago. This was the first evidence
pointing to the African origins of modern humans.
Statistical Methods for Studying DNA Evolution
Focusing at an early stage on DNA sequence data, from the late 1970s
Dr. Nei initiated mathematical modeling of DNA evolution. In the
mid-1980s, he worked on statistical methods for estimating the number of
nonsynonymous substitutions (nucleotide substitutions that result in
amino acid replacements) and synonymous substitutions (those that do not
result in amino acid replacements), and proposed that the ratio between
the two be used to identify gene regions in which natural selection is
operating strongly. These methods are now being utilized by a large
number of investigators.
Phylogenetic Analysis of DNA and Protein Sequences
During the 1980s, Dr. Nei began to construct a mathematical theory of
the phylogenetic relationships of genes, using molecular data such as
DNA and protein sequences. He and his collaborators were the first to
clarify the theoretical relationships of gene trees and species trees,
thus providing a theoretical basis for explaining many experimental
observations that had previously defied interpretation. With one of his
graduate students, Dr. Nei also developed a technique of inferring
molecular phylogenies known as the gneighbor-joining method,h which
has become the most widely used method of constructing phylogenetic
Evolution of Immune System Genes
In 1988, Dr. Nei turned his attention to the major histocompatibility
complex (MHC) genes, which are involved in immune responses such as
rejection of organ transplants, and showed that the puzzling variability
of these genes in human populations is due to a special pattern of
evolutionary change of DNA that occurs when MHC genes protect the host
from invaders such as viruses and bacteria. This evolutionary pattern
has since been shown to hold true not only for humans but for
vertebrates in general.
Dr. Nei also studied gmultigene families,h in which multiple copies of
member genes are present in the genome, as is generally the case for the
immune system genes. He discovered that the member genes typically
evolve according to a pattern called gbirth-and-death evolution,h in
which, after gene duplication, the member genes evolve more or less
independently of one another, with some staying in the genome for a long
time and others disappearing.
These achievements laid the foundation on which rests the theoretical
framework of current molecular evolutionary biology. Thus, Dr. Nei has
made an enormous contribution to the development of his chosen field of
Nei, M. 1969. Gene duplication and nucleotide substitution in
evolution. Nature 221:40-42.
Nei, M. 1972. Genetic distance between populations. American
Nei, M. 1973. Analysis of gene diversity in subdivided populations.
Proceedings of the National Academy of Sciences USA 70:3321-3323.
Nei, M. 1975. Molecular Population Genetics and Evolution.
North-Holland, Amsterdam and New York.
Nei, M. 1978. Estimation of average heterozygosity and genetic distance
from a small number of individuals. Genetics 89:583-590.
Nei, and Li, W. H. 1979. Mathematical model for studying genetic
variation in terms of restriction endonucleases. Proceedings of the
National Academy of Sciences USA 76:5269-5273.
Nei, M. and Roychoudhury, A. K. 1982. Genetic relationship and evolution
of human races.@Evolutionary Biology 14:1-59.
Saitou, N. and Nei, M. 1987. The neighbor-joining method: a new method
for reconstructing@phylogenetic trees. Molecular Biology and
Nei, M. 1987. Molecular Evolutionary Genetics. Columbia
University Press, New York.
Hughes, A. L. and Nei, M. 1988. Pattern of nucleotide substitution at
major histocompatibility complex class I loci reveals overdominant
selection. Nature 335:167-170.
Nei, M. Gu., X., and Sitnikova, T. 1997. Evolution by the
birth-and-death process in multigene@families of the vertebrate immune
system. Proceedings of the National Academy of Sciences USA
Nei, M. and Kumar, S. 2000. Molecular Evolution and Phylogenetics.
Oxford University Press, Oxford.