Endosymbiosis has been directly observed!
The Paper:
Auto-/heterotrophic endosymbiosis evolves in a mature stage of ecosystem development in a microcosm composed of an alga, a bacterium and a ciliate
Abstract
We investigate an ecological mechanism by which endosymbiotic associations evolve, with a particular focus on the relationship between the evolution of endosymbiosis between auto- and heterotrophic organisms, and the stages of ecosystem development. For this purpose we conducted a long-term microcosm culture composed of three species, a green alga (Chlorella vulgaris), a bacterium (Escherichia coli), and a ciliated protozoan (Tetrahymena thermophila) for 3 years. During this culture T. thermophila cells harboring Chlorella cells emerged by phagocytotic uptake, and increased in frequency, reaching ca. 80-90%. This level was maintained in the late stage of ecosystem dynamics. Analysis of the ecosystem dynamics in the microcosm revealed that a complex causal process through direct/indirect interactions among ecosystem components led to reduction in dissolved O2 and food (E. coli) available to the T. thermophila, which gave a selective advantage to the organisms in the endosymbiotic association. This result suggests that the endosymbiosis evolves in a mature stage of ecosystem development, where reproduction and survival of prospective partner organisms is highly resource-limited and density-dependent, favoring efficient matter/energy transfers among participating organisms due to physical proximity. Consequently, a complex web of interactions and pathways of matter/energy flow in ecosystem evolves from an initially simple one.
Read the entire paper for free here: https://www.researchgate.net/publicat...
Watch video Endosymbiosis has been directly observed! online without registration, duration hours minute second in high quality. This video was added by user Stated Clearly 23 May 2024, don't forget to share it with your friends and acquaintances, it has been viewed on our site 8,349 once and liked it 723 people.