Archaebacteria and Archezoa

  title={Archaebacteria and Archezoa},
  author={T Cavalier-smith},
On the origin of eukaryotic cells; the evolution of a theory
The formation of certain organelles such as the nucleus and the mitochondria have been fundamental in the evolution of eukaryotes and the evolutionary relationship between Eukaryota and the other two domains can tell us more about the way eUKaryotes have evolved from prokaryotes.
Multidomain ribosomal protein trees and the planctobacterial origin of neomura (eukaryotes, archaebacteria)
Unique presence of key pre-neomuran characters favours Planctobacteria only as ancestral to neomura, which apparently arose by coevolutionary repercussions (explained here in detail, including RP replacement) of simultaneous outer membrane and murein loss.
Origins of peptidases
When mechanisms are not enough: The origin of eukaryotes and scientific explanation
The appeal to mechanisms in scientific explanation is commonplace in contemporary philosophy of science. In short, mechanists argue that an explanation of a phenomenon consists of citing the
Introduction into Parasitic Protozoa
The protozoan parasites that infect farm animals and pets, and are the subject of this book, belong to the first three supergroups: SAR, Excavata, Amoebozoa, Archaeplastida, and Ophistokonta.


The origin of cells: a symbiosis between genes, catalysts, and membranes.
It is argued that the obcell was the substratum for the origin of DNA replication; DNA segregation by the growth and division of the peptidoglycan murein; periplasmic solute-binding proteins; bioenergetics; and facilitated diffusion of nutrients across membranes, and that it played the major role in the replacement of ribozymes by protein catalysts.
Phylogenetic meaning of the kingdom concept: an unusual ribosomal RNA from Giardia lamblia.
Investigation of the small subunit ribosomal RNA (16S-like rRNA) from the protozoan Giardia lamblia provided a new perspective on the evolution of nucleated cells and challenged the phylogenetic significance of multiple eukaryotic kingdoms.
Ribosomal RNA sequence suggests microsporidia are extremely ancient eukaryotes
Comparison sequence analysis shows that the small subunit rRNA of the microsporidium Vairimorpha necatrix is more unlike those of other eukaryotes than any known eukARYote 18S rRNA sequence, and concludes that the lineage leading to microspora branched very early from that leading to other eUKaryotes.
Phylogenetic analysis based on rRNA sequences supports the archaebacterial rather than the eocyte tree
It is reported that analysis of small subunit data by the neighbour-joining and maximum parasimony methods favours the archaebacterial tree and that computer simulations using either the arch aebacterial or the eocyte tree as a model tree show that the probability of recovering the model tree is very high for both the neighbour and maximum parsimony methods but is relatively low for the evolutionary parsimony method.
Origin of the algae
It is shown that rhodophytes, chromophytes and chlorophytes emerge as three distinct groups late among eukaryotes, that is, close to the metazoa–metaphytes radiation, which implies a relatively late occurrence of eukARYotic photosynthetic symbiosis.
What, if anything, is Prochloron?
Origin of the eukaryotic nucleus determined by rate-invariant analysis of rRNA sequences
Using evolutionary parsimony, a newly developed rate-invariant treeing algorithm, the eukaryotic ribosomal rRNA genes are shown to have evolved from the eocytes, a group of extremely thermophilic, sulphur-metabolizing, anucleate cells that probably lacked nuclei, metabolized sulphur and lived at near-boiling temperatures.