James A. Lake (born August 10, 1941, Kearney, Nebraska) is an American evolutionary biologist and a Distinguished Professor of Molecular, Cell, and Developmental Biology and of Human Genetics at UCLA. Lake is best known for the New Animal Phylogeny and for the first three-dimensional structure of the

ribosome Ribosomes ( ) are macromolecular machines, found within all cells, that perform biological protein synthesis (mRNA translation). Ribosomes link amino acids together in the order specified by the codons of messenger RNA (mRNA) molecules to f ...

. 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. Founded in 1876, five months before Colorado became a state, it is the flagship university of the University of Colorado syst ...

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 higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, the ...

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

MIT The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the m ...

and

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

, an Assistant Professorship of Cell Biology in George Palade’s Department at

Rockefeller University The Rockefeller University is a private biomedical research and graduate-only university in New York City, New York. It focuses primarily on the biological and medical sciences and provides doctoral and postdoctoral education. It is classifie ...

(1970–73) and an Associate Professorship of Cell Biology at NYU Medical School (1973–76), he became a Professor of Molecular Biology in Biology at

UCLA The University of California, Los Angeles (UCLA) is a public land-grant research university in Los Angeles, California. UCLA's academic roots were established in 1881 as a teachers college then known as the southern branch of the California St ...

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 () 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 & Connec ...

ancestors of

eukaryotes 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 ...

, evidence for early prokaryotic endosymbioses,

genomic Genomics is an interdisciplinary field of 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, three-dim ...

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. It possesses several important biological specimen, manuscript and literature colle ...

for elucidating the new animal phylogeny. 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 (natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life form ...

. 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 unicellular and/or multicellular organisms other than by the ("vertical") transmission of DNA from parent to offspring (reproduction). H ...

, 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 PCR or pcr may refer to: Science * Phosphocreatine, a phosphorylated creatine molecule * Principal component regression, a statistical technique Medicine * Polymerase chain reaction ** COVID-19 testing, often performed using the polymerase chain r ...

and increased ease of sequencing rDNA in the 1990s, Lake focused on the bilateral animals, and recognised that there were questions over the placement of the

lophophorate The Lophophorata are a Lophotrochozoan clade consisting of the Brachiozoa and the Bryozoa. They have a lophophore. Molecular phylogenetic analyses suggest that lophophorates are protostomes, but on morphological grounds they have been assesse ...

animals, such as

bryozoans Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a l ...

phoronids Phoronids (scientific 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 trochozoan 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, whi ...

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

deuterostomes Deuterostomia (; in Greek) are animals typically characterized by their anus forming before their mouth during embryonic development. The group's sister clade is Protostomia, animals whose digestive tract development is more varied. Some exampl ...

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

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estim ...

–

annelid The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecolo ...

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, brachiop ...

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, chelicerata, crustaceans, and myriapods), Nematoda, and several smaller phyla. They were first defined by Aguinaldo ''et al.'' in 1997, based mainly on phylogenetic tr ...

, a second protostomian superphylum sister to the Lophotrochozoa.

Endosymbiosis research

Lake also explored concepts concerning the deep phylogenetic origins of the

eukaryotic cell 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. Bacte ...

. In the

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

, 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 Evolutionary biologists Fellows of the American Academy of Arts and Sciences Symbiogenesis researchers