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 ...
. 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.
George Palade
George Emil Palade (; November 19, 1912 – October 7, 2008) was a Romanian cell biologist. Described as "the most influential cell biologist ever",
’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 classif ...
(1970–73) and an Associate Professorship of Cell Biology at
NYU Medical School
NYU Grossman School of Medicine is a medical school of New York University, a Private university, private research university in New York City. It was founded in 1841 and is one of two medical schools of the university, with the other being the L ...
(1973–76), he became a Professor of Molecular Biology in Biology at UCLA 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 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. Bacte ...
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 ...
new animal phylogeny
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in w ...
. The Medal is awarded to individuals who have made major advances in evolutionary biology. 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, 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 sequences could be used to determine metazoan relationships. Interpretation of the trees was complicated by the problem of Long branch attraction (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
The Bilateria or bilaterians are animals with bilateral symmetry as an embryo, i.e. having a left and a right side that are mirror images of each other. This also means they have a head and a tail (anterior-posterior axis) as well as a belly and ...
, 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
Protostomia () is the clade of animals once though ...
lophophorates
The lophophore () is a characteristic feeding organ possessed by four major groups of animals: the Brachiopoda, Bryozoa, Hyolitha, and Phoronida, which collectively constitute the protostome group Lophophorata.deuterostomes 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 esti ...
–
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 ecol ...
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, brachi ...
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. In the eocyte hypothesis, Lake and colleagues proposed that eukaryotes (animals, fungi, plants, and protists) evolved from a specific group of thermophilic prokaryotes, the "
eocyte
The Thermoproteota (also known as crenarchaea) are archaea that have been classified as a phylum of the Archaea domain. Initially, the Thermoproteota were thought to be sulfur-dependent extremophiles but recent studies have identified character ...