Showing posts with label archaea. Show all posts
Showing posts with label archaea. Show all posts

Friday, April 25, 2025

This Single-Celled Microbe Can Transform Into a Multicellular Creature

 A recent study has revealed that Haloferax volcanii, a single-celled archaeon thriving in hypersaline environments like the Dead Sea, can morph into a multicellular structure under physical pressure. This remarkable transformation was discovered by researchers led by Theopi Rados at Brandeis University. When placed under pressures of 10 to 100 kPa—similar to underwater conditions—H. volcanii’s soft, flexible outer layer allows it to flatten and then grow into organized clusters of cells resembling tissue.

Over time, these clusters form distinct cell types: flatter, wedge-shaped peripheral cells and taller, scutoid cells in the center, which are also common in curved eukaryotic tissues like the gut and skin. These scutoid structures, long thought to be exclusive to complex eukaryotic organisms, may actually predate them, hinting at ancient origins of multicellularity.



The microbe’s transformation, enabled by its dynamic membrane-like surface rather than a rigid cell wall, suggests that archaea may be highly sensitive to mechanical stimuli. This discovery challenges the notion that complex tissue formation is exclusive to more advanced life forms and underscores how multicellularity might evolve from simple building blocks through environmental pressures.

Friday, January 27, 2017

Evolution of the Eukaryotic Cell

         The article by James McInerney and May O'Connell discusses the results of a study conducted by a team consisting of over 10 individuals from countries around the globe. Their research uncovered a group of archaea that may help link eukaryotic cells too their prokaryotic ancestors. They named this new superphylum Asgard. The Asgard group is not officially recognized but the team is confident that their analyses support its existence.


         Research done several decades ago indicated that there were groups of archaea that had yet to be discovered, located within ocean sediments. The research team used this as their basis and collected sediments from several locations around the world. They then sequenced over 644 billion nucleotides from the mixture of organisms present in the samples. This sequencing revealed ribosomal gene similarities to the groups of archaea known as Lokiarchaeota, Thorarchaeota, Odinarchaeota, and Heimdallarchaeota.
         The group Lokiarchaeota was previously the closest link between eukaryotic cells and Prokaryotic cells we had discovered. This research is important to understanding the theory of a cellular merger that created the first eukaryotic cells. Members of the Asgard group contain types of genes that were believed to have originated early in eukaryotic evolution. I believe this research is not only exciting but important. We are getting closer and closer to understanding the origins of complex life, giving us insight into not only our planet but also life on other planets.

Monday, April 11, 2016

New 'Tree of Life' Diagram

A team of scientists have recently recreated the "Tree of Life" diagram. They extended the amount of organisms primarily under the bacteria branch because they have found such a vast amount in mud of meadow-lands. They pulled pieces of their DNA to be analyzed through a separated that separated each entry to create the new diagram. The new tree has a thinner branch for eukaryotes with archaeabacteria being shown as having a closer relationship between the two. They have selected 3,000 species to be on this new tree with over 1,000 being newly discovered species. However there is speculation that some of these species could be chimera which would have a mixture of DNA from more than one organism. There is also the debate of whether the bacteria branch has begun to plateau or if there is an astoundingly larger amount out to still be discovered.

Aesthetically, the tree looks a lot more interesting than what Darwin's original "Tree of Life" from his 1859 book "On the Origin of Species". There is so much more to the new diagram, and it gives a better idea of how vast the amount of bacteria there are especially in comparison to eukaryotes such as mammals. I believe that there are more bacteria to be discovered that will only belittle the amount currently depicted. With the advancement of technology discovering new species should be simple. I do find it peculiar how archaeabacteria is actually more closely related to eukaryotes as opposed to bacteria. Archaeabacteria seem like very simple organisms that do not have the same complexity of eukaryotes.
Figure 1. New "Tree of Life" Diagram.

Figure 2. Darwin's Original "Tree of Life" Diagram