James A. Lake (born August 10, 1941) is an American evolutionary biologist and a Distinguished Professor of Molecular, Cell, and Developmental Biology and of Human Genetics at

UCLA The University of California, Los Angeles (UCLA) is a public land-grant research university in Los Angeles, California, United States. Its academic roots were established in 1881 as a normal school then known as the southern branch of the C ...

. Lake is best known for the New Animal Phylogeny and for the first three-dimensional structure of the

ribosome Ribosomes () are molecular machine, macromolecular machines, found within all cell (biology), cells, that perform Translation (biology), biological protein synthesis (messenger RNA translation). Ribosomes link amino acids together in the order s ...

. He has also made significant contributions to understanding genome evolution across all kingdoms of life, including discovering informational and operational genes, elucidating the complexity hypothesis for gene transfer, rooting the tree of life, and understanding the early transition from prokaryotic to eukaryotic life.

Education

Jim Lake graduated from the

University of Colorado, Boulder The University of Colorado Boulder (CU Boulder, CU, or Colorado) is a public research university in Boulder, Colorado, United States. Founded in 1876, five months before Colorado became a state, it is the flagship university of the University o ...

with a BA in physics in 1963. In 1967 he was awarded a Ph.D. in physics from the

University of Wisconsin, Madison A university () is an institution of tertiary education and research which awards academic degrees in several academic disciplines. ''University'' is derived from the Latin phrase , which roughly means "community of teachers and scholars". Univ ...

on the structure of tRNA. Following postdocs in Molecular Biology at

MIT The Massachusetts Institute of Technology (MIT) is a private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of modern technology and sc ...

and

Harvard Medical School Harvard Medical School (HMS) is the medical school of Harvard University and is located in the Longwood Medical and Academic Area, Longwood Medical Area in Boston, Massachusetts. Founded in 1782, HMS is the third oldest medical school in the Un ...

, an Assistant Professorship of Cell Biology in

George Palade George Emil Palade (; November 19, 1912 – October 7, 2008) was a Romanian-American cell biologist.Archived< ...

’s Department at

Rockefeller University The Rockefeller University is a Private university, private Medical research, biomedical Research university, research and graduate-only university in New York City, New York. It focuses primarily on the biological and medical sciences and pro ...

(1970–73) and an Associate Professorship of Cell Biology at

NYU Medical School The New York University Grossman School of Medicine is a medical school of New York University, a private research university in New York City. It was founded in 1841 and is one of two medical schools of the university, the other being the NYU Gr ...

(1973–76), he became a Professor of Molecular Biology in Biology at

in 1976 and is currently a Distinguished Professor of Molecular, Cell, and Developmental Biology and of Human Genetics.

Research

Lake's research focuses in four areas:

prokaryotic A prokaryote (; less commonly spelled procaryote) is a single-celled organism whose cell lacks a nucleus and other membrane-bound organelles. The word ''prokaryote'' comes from the Ancient Greek (), meaning 'before', and (), meaning 'nut' ...

ancestors of

eukaryotes The eukaryotes ( ) constitute the domain of Eukaryota or Eukarya, organisms whose cells have a membrane-bound nucleus. All animals, plants, fungi, seaweeds, and many unicellular organisms are eukaryotes. They constitute a major group of ...

, evidence for early prokaryotic endosymbioses,

genomic Genomics is an interdisciplinary field of molecular biology focusing on the structure, function, evolution, mapping, and editing of genomes. A genome is an organism's complete set of DNA, including all of its genes as well as its hierarchical, ...

analyses, and rooting of the biological tree of life.

Darwin-Wallace Medal

In 2011, Lake was presented the Darwin-Wallace Medal by the

Linnean Society of London The Linnean Society of London is a learned society dedicated to the study and dissemination of information concerning natural history, evolution, and Taxonomy (biology), taxonomy. It possesses several important biological specimen, manuscript a ...

for elucidating the

new animal phylogeny Animals are multicellular, eukaryotic organisms in the Biology, biological Kingdom (biology), kingdom Animalia (). With few exceptions, animals heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, ...

. The Medal is awarded to individuals who have made major advances in

evolutionary biology Evolutionary biology is the subfield of biology that studies the evolutionary processes such as natural selection, common descent, and speciation that produced the diversity of life on Earth. In the 1930s, the discipline of evolutionary biolo ...

. Lake has made a number of highly significant contributions toward understanding diverse aspects of genome evolution across all kingdoms of life. These include discovering informational and operational genes, developing the complexity hypothesis for horizontal/lateral

gene transfer Horizontal gene transfer (HGT) or lateral gene transfer (LGT) is the movement of genetic material between organisms other than by the ("vertical") transmission of DNA from parent to offspring (reproduction). HGT is an important factor in the e ...

, and rooting the tree of life, topics on which he has published over 160 papers. In the mid-1980s it was becoming clear that

ribosomal RNA Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal ...

sequences could be used to determine metazoan relationships. Interpretation of the trees was complicated by the problem of

Long branch attraction In phylogenetics, long branch attraction (LBA) is a form of systematic error whereby distantly related lineages are incorrectly inferred to be closely related. LBA arises when the amount of molecular or morphological change accumulated within a lin ...

(LBA). By developing new algorithms that were less sensitive to these LBA artefacts, Lake was able to show that the Annelida-Mollusca lineage is the sister group of an arthropod subgroup. This finding was contrary to the Articulata hypothesis that grouped arthropods with annelids, and was nearly universally endorsed at that time. With the advent of PCR and increased ease of sequencing rDNA in the 1990s, Lake focused on the

bilateral animals Bilateria () is a large clade of animals characterised by bilateral symmetry during embryonic development. This means their body plans are laid around a longitudinal axis with a front (or "head") and a rear (or "tail") end, as well as a left–r ...

, and recognised that there were questions over the placement of the

lophophorate The Lophophorata (also called Tentaculata; not to be confused with Tentaculata Eschscholtz 1825, a class within the Ctenophora) are a Lophotrochozoan clade consisting of the Brachiozoa and the Bryozoa. They have a lophophore. Molecular phyloge ...

animals, such as

bryozoans Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic animal, aquatic invertebrate animals, nearly all living in sedentary Colony (biology), colonies. Typically about long, they have a spe ...

phoronids Phoronids ( taxonomic name Phoronida, sometimes called horseshoe worms) are a small phylum of marine animals that filter-feed with a lophophore (a "crown" of tentacles), and build upright tubes of chitin to support and protect their soft bodies ...

, and

brachiopods Brachiopods (), phylum Brachiopoda, are a phylum of animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the fron ...

. Lake provided clear DNA-based evidence indicating that the lophophorates were not

deuterostomes Deuterostomes (from Greek: ) are bilaterian animals of the superphylum Deuterostomia (), typically characterized by their anus forming before the mouth during embryonic development. Deuterostomia comprises three phyla: Chordata, Echinodermata, ...

as had been widely believed. In fact, they were most closely related to the

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

–

annelid The annelids (), also known as the segmented worms, are animals that comprise the phylum Annelida (; ). The phylum contains over 22,000 extant species, including ragworms, earthworms, and leeches. The species exist in and have adapted to vario ...

clade. The result of this research was the creation of a new super-phylum, the

Lophotrochozoa Lophotrochozoa (, "crest/wheel animals") is a clade of protostome animals within the Spiralia. The taxon was established as a monophyletic group based on molecular evidence. The clade includes animals like annelids, molluscs, bryozoans, and brach ...

containing molluscs, annelids, lophophorates, and other animals. Lake recognised that long branch attraction was a severe problem for the mostly rapidly evolving nematodes and was able to provide rDNA sequences from a number of slowly evolving nematodes in order to bypass this difficulty. This sampling showed that the moulting animals form a clade, called the

Ecdysozoa Ecdysozoa () is a group of protostome animals, including Arthropoda (insects, chelicerates (including arachnids), crustaceans, and myriapods), Nematoda, and several smaller phylum (biology), phyla. The grouping of these animal phyla into a single ...

, a second protostomian superphylum sister to the Lophotrochozoa.

Endosymbiosis research

Lake also explored concepts concerning the deep phylogenetic origins of the

eukaryotic cell The eukaryotes ( ) constitute the domain of Eukaryota or Eukarya, organisms whose cells have a membrane-bound nucleus. All animals, plants, fungi, seaweeds, and many unicellular organisms are eukaryotes. They constitute a major group of Out ...

. In the

eocyte hypothesis The eocyte hypothesis in evolutionary biology proposes that the eukaryotes originated from a group of prokaryotes called eocytes (later classified as Thermoproteota, a group of archaea). After his team at the University of California, Los Angele ...

, Lake and colleagues proposed that eukaryotes (animals, fungi, plants, and protists) evolved from a specific group of thermophilic prokaryotes, the " eocyte" archaebacteria.

References

External links

* {{DEFAULTSORT:Lake, James A. 1941 births Living people University of Wisconsin–Madison College of Letters and Science alumni People from Kearney, Nebraska 21st-century American biologists American evolutionary biologists Fellows of the American Academy of Arts and Sciences Symbiogenesis researchers