page_title: Evolution of bacteria
section_title: Process of Bacterial Evolution
hierarchical_section_title: Evolution of bacteria / Defining Bacteria / Process of Bacterial Evolution
caption_attribution_description: English: Thermophile bacteria isolated from deep-sea vent fluids. This organism eats sulfur and hydrogen and fixes its own carbon from carbon dioxide. Scanning electron micrograph.
context_page_description: The evolution of bacteria has progressed over billions of years since the Precambrian time with their first major divergence from the archaeal/eukaryotic lineage roughly 3.2-3.5 billion years ago. This was discovered through gene sequencing of bacterial nucleoids to reconstruct their phylogeny. Furthermore, evidence of permineralized microfossils of early prokaryotes was also discovered in the Australian Apex Chert rocks, dating back roughly 3.5 billion years ago during the time period known as the Precambrian time. This suggests that an organism in of the phylum Thermotogae was the most recent common ancestor of modern bacteria.
  Further chemical and isotopic analysis of ancient rock reveals that by the Siderian period, roughly 2.45 billion years ago, oxygen had appeared. This indicates that oceanic, photosynthetic Cyanobacteria evolved during this period because they were the first microbes to produce oxygen as a byproduct of their metabolic process. Therefore, this phylum was thought to have been predominant roughly 2.3 billion years ago.
context_section_description: Bacteria evolve in a similar process to other organisms. This is through the process of natural selection, whereby beneficial adaptations are passed onto future generations until the trait becomes common within the entire population. However, bacteria reproduce via binary fission, which is a form of asexual reproduction meaning the daughter cell and the parent cell are genetically identical. This makes bacteria susceptible to environmental pressures. This is overcome by sharing genetic information by either transduction, transformation, or conjugation. This allows for new genetic and physical adaptations to evolve, thus allowing bacteria to adapt to their environment and evolve. Furthermore, bacteria can reproduce in as little as 20 minutes, which allows for fast adaptation meaning new strains of bacteria can evolve quickly. This has become an issue regarding antibiotic resistant bacteria.
caption: Thermophile bacteria from deep-sea vent. This organism eats sulfur and hydrogen and fixes its own carbon from carbon dioxide.
exif: {"Image Orientation": "Horizontal (normal)", "Image XResolution": "300", "Image YResolution": "300", "Image ResolutionUnit": "Pixels/Inch", "Image ExifOffset": "90", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "892", "EXIF ExifImageLength": "892"}