<h2>Ring of Life Models</h2>
<p>Others have proposed abandoning any tree-like model of phylogeny in favor of a ring structure, the so-called “<strong>ring of life</strong>” (see the figure below); a phylogenetic model where all three domains of life evolved from a pool of primitive prokaryotes. Lake, again using the <a data-lesson="conditioned-behavior" data-subject="biology" data-tutorial="population-community-ecology" href="https://app.ulearngo.com/biology/population-community-ecology/conditioned-behavior">conditioned</a> reconstruction algorithm, proposes a ring-like model in which species of all three domains—Archaea, Bacteria, and Eukarya—evolved from a single pool of gene-swapping prokaryotes. His laboratory proposes that this structure is the best fit for data from extensive <a href="https://app.ulearngo.com/tutorials/introducing-genetics/dna">DNA</a> analyses performed in his laboratory, and that the ring model is the only one that adequately takes HGT and genomic fusion into account. However, other phylogeneticists remain highly skeptical of this model.</p>
<div class="wp-caption alignnone" style="width: 544px"><img alt="Illustration shows a ring with the words “pool of primitive prokaryotes” in the middle. Three arrows point outward from the ring, pointing at the three domains, Bacteria, Archaea, and Eukarya, indicating that all three domains arose from a common pool of prokaryotes." height="399" src="https://data.ulearngo.com/assets/5f758d17-ca30-423f-bf94-6e997f26e82f" width="544"/><p class="wp-caption-text">According to the “ring of life” phylogenetic model, the three domains of life evolved from a pool of primitive prokaryotes.</p></div>
<p>In summary, the “tree of life” model proposed by Darwin must be modified to include HGT. Does this mean abandoning the tree model completely? Even Lake argues that all attempts should be made to discover some modification of the tree model to allow it to accurately fit his data, and only the inability to do so will sway people toward his ring proposal.</p>
<p>This doesn’t mean a tree, web, or a ring will correlate completely to an accurate description of phylogenetic relationships of life. A consequence of the new thinking about phylogenetic models is the idea that Darwin’s original conception of the <a href="https://app.ulearngo.com/tutorials/history-of-life-ii/perspectives-on-the-phylogenetic-tree">phylogenetic tree</a> is too simple, but made sense based on what was known at the time. However, the search for a more useful model moves on: each model serving as hypotheses to be tested with the possibility of developing new models. This is how <a href="https://app.ulearngo.com/tutorials/introducing-study-of-life/basic-applied-science">science</a> advances. These models are used as visualizations to help construct hypothetical evolutionary relationships and understand the massive amount of data being analyzed.</p>

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Ring of Life Models

Biology studies life and living organisms. Biology can be divided into different sections that cover the morphology, physiology, anatomy, behavior, and so on of living organisms.

Biology

Explore the history of life and evolutionary relationships by learning about phylogenetic trees, the levels of classification, building and analyzing them, and understanding the limitations and different perspectives on the classic model, genome fusion, and web and network models.


Ring of Life Models

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