Universal common ancestry, LUCA, and the Tree of Life: three distinct hypotheses about the evolution of life

2018 ◽  
Vol 33 (5-6) ◽  
Author(s):  
Joel Velasco
Keyword(s):  
Tree Of Life ◽  
Common Ancestry ◽  
Evolution Of Life

scholarly journals Genome beginnings: rooting the tree of life

2009 ◽  
Vol 364 (1527) ◽  
pp. 2177-2185 ◽  
Author(s):  
James A. Lake ◽  
Ryan G. Skophammer ◽  
Craig W. Herbold ◽  
Jacqueline A. Servin
Keyword(s):  
Common Ancestor ◽  
Lipid Membrane ◽  
Rooted Tree ◽  
Lipid Synthesis ◽  
Tree Of Life ◽  
Last Common Ancestor ◽  
Paralogous Gene ◽  
Gene Sets ◽  
Evolution Of Life ◽  
New Perspective

A rooted tree of life provides a framework to answer central questions about the evolution of life. Here we review progress on rooting the tree of life and introduce a new root of life obtained through the analysis of indels, insertions and deletions, found within paralogous gene sets. Through the analysis of indels in eight paralogous gene sets, the root is localized to the branch between the clade consisting of the Actinobacteria and the double-membrane (Gram-negative) prokaryotes and one consisting of the archaebacteria and the firmicutes. This root provides a new perspective on the habitats of early life, including the evolution of methanogenesis, membranes and hyperthermophily, and the speciation of major prokaryotic taxa. Our analyses exclude methanogenesis as a primitive metabolism, in contrast to previous findings. They parsimoniously imply that the ether archaebacterial lipids are not primitive and that the cenancestral prokaryotic population consisted of organisms enclosed by a single, ester-linked lipid membrane, covered by a peptidoglycan layer. These results explain the similarities previously noted by others between the lipid synthesis pathways in eubacteria and archaebacteria. The new root also implies that the last common ancestor was not hyperthermophilic, although moderate thermophily cannot be excluded.

Epilogue

2021 ◽  
pp. 196-204
Author(s):  
Harvey Whitehouse
Keyword(s):  
Tree Of Life ◽  
Lessons Learned ◽  
Common Ancestry ◽  
Shared Experiences ◽  
Shared Set ◽  
Outgroup Derogation

Briefly drawing together the main themes of the book in a roundup of ‘lessons learned’, the epilogue sketches out a vision for new forms of group alignment that transcend the parochialism of ancient imagistic worlds and the forms of outgroup derogation and intolerance that doctrinal systems foment, replacing them with new forms of extended fusion. These are required to address all the major challenges of the Anthropocene, including the need to recognize a shared set of human obligations, alongside our much-vaunted rights. As we strive to combat racism and fuel instead the recognition that we are all members of one species, we may also seek to extend that intuition of shared biological essence to all other outgrowths on the tree of life, with which we share a common ancestry. Joining in new rituals that emphasize these sorts of shared experiences and shared bodies will be vital because, in the end, our fates are entwined and the ritual animal is, well, just another animal.

Sacred Trees in the Garden of Eden and Their Ancient Near Eastern Precursors

2012 ◽  
Vol 3 (3) ◽  
pp. 267-301
Author(s):  
Michaela Bauks
Keyword(s):  
Sacred Space ◽  
Tree Of Life ◽  
Wisdom Literature ◽  
Garden Of Eden ◽  
Historical Approach ◽  
Near Eastern ◽  
1 Enoch

Interpretations of the trees in the Garden of Eden misunderstand their significance by focusing on sin or a theological “fall.” A tradition-historical approach to the motif of trees in ancient Near Eastern literature and imagery reveals their multivalent quality. Trees are connected with fertility and goddess devotion but also with the power and divine sanction given to kings and dynasties, and with the potency of sacred space, on which humans and the divine come together and meet. As cross-temporal motifs, trees are regularly associated with life-giving and blessing (a plant of rejuvenation; a tree of life); a connection of trees to knowledge and meaning appears as well, in wisdom literature, and in the book of 1 Enoch. Language of a world tree or cosmic tree, though useful conceptually, is a modern imposition on the ancient evidence. More evident from the ancient setting is the image of felling trees, which indicates the downfall of human leaders, especially kings, because of their hubris. Ultimately, sacred trees have an ambivalent value, as a source of both contestation and progress.

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