Bizarre early life forms ate better when they ate together

Nature ◽  
2019 ◽  
Vol 570 (7762) ◽  
pp. 418-418
Keyword(s):  
Early Life ◽  
Life Forms

scholarly journals Relaxed Substrate Specificity in Qβ Replicase through Long-Term In Vitro Evolution

Life ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 32
Author(s):  
Kohtoh Yukawa ◽  
Ryo Mizuuchi ◽  
Norikazu Ichihashi
Keyword(s):  
Substrate Specificity ◽  
Early Life ◽  
Evolutionary History ◽  
Rna Replication ◽  
Life Forms ◽  
In Vitro Evolution ◽  
Present Evidence ◽  
Major Transition

A change from RNA- to DNA-based genetic systems is hypothesized as a major transition in the evolution of early life forms. One of the possible requirements for this transition is a change in the substrate specificity of the replication enzyme. It is largely unknown how such changes would have occurred during early evolutionary history. In this study, we present evidence that an RNA replication enzyme that has evolved in the absence of deoxyribonucleotide triphosphates (dNTPs) relaxes its substrate specificity and incorporates labeled dNTPs. This result implies that ancient replication enzymes, which probably evolved in the absence of dNTPs, could have incorporated dNTPs to synthesize DNA soon after dNTPs became available. The transition from RNA to DNA, therefore, might have been easier than previously thought.

The Biography of the Earth

2021 ◽  
pp. 163-180
Author(s):  
Elisabeth Ervin-Blankenheim
Keyword(s):  
Early Life ◽  
Plate Tectonics ◽  
Life Forms ◽  
Snowball Earth ◽  
The Moon ◽  
Geologic Time ◽  
Earth Systems ◽  
Organic Life ◽  
The Earth ◽  
Geologic Record

The way the planet has changed through geologic time, and life on it, the account of the Earth, is the topic of this and the next three chapters, starting in this chapter with the Precambrian Supereon. The overarching principles of geologic time, plate tectonics, and evolution worked dynamically to create the biography of the planet. This chapter traces back to the recesses of the geologic record and early Earth, from its birth and the formation of the Moon through seven-eighths of its existence, a huge span of time. Early life forms emerged during this supereon in the Archean Eon and had a profound influence on other Earth systems. Life interacted and changed the chemistry of the atmosphere through photosynthesis, so much so that the changes are thought to have sent planetary systems over an edge into multiple “Snowball Earth” episodes when most of the planet froze over. In addition to the beginning of organic life and climate, the emergence and configuration of the continents during the Precambrian are covered. Events of this supereon set the stage for the burgeoning of life forms in the next eon, the Phanerozoic.

Early Life Forms

1895 ◽  
Vol 40 (1038supp) ◽  
pp. 16596-16597
Keyword(s):  
Early Life ◽  
Life Forms

A biota of Ediacaran aspect from lower Cambrian strata on the Digermul Peninsula, Arctic Norway

1999 ◽  
Vol 136 (6) ◽  
pp. 633-642 ◽  
Author(s):  
T. P. CRIMES ◽  
D. McILROY
Keyword(s):  
Morphological Variation ◽  
Mass Extinction ◽  
Early Life ◽  
Lower Cambrian ◽  
Life Forms ◽  
Growing Body ◽  
Extinction Event ◽  
Late Neoproterozoic ◽  
Mass Extinction Event

Three elements of the ‘Ediacara fauna’ are described from lower Cambrian strata on the Digermul Peninsula, Norway. Nimbia occlusa Fedonkin, 1980 and Tirasiana sp. occur approximately 80 m above the base of the Lower Breivik Member, which approximately coincides with the Neoproterozoic–Cambrian boundary. A specimen of Cyclomedusa sp. has also been found in the Lower Duolbasgaissa Member about 600 m above the boundary, in rocks of trilobite-bearing age.These discoveries add to a growing body of evidence that some elements of the dominantly Neoproterozoic Ediacara fauna continue into the Phanerozoic, thereby diminishing the scope of a possible late Neoproterozoic mass-extinction event.The taxa described here, particularly Nimbia and Cyclomedusa, also occur at many other localities within Neoproterozoic strata and, in common with other elements of the Ediacara fauna, display remarkable morphological variation. Some of this diversity in form is probably caused by environmental and preservational factors. The possibility that it may, at least in part, reflect an inability of these early life forms to replicate faithfully their genes during reproduction should, however, not be overlooked.

scholarly journals How long can left and right handed life forms coexist?

2004 ◽  
Vol 3 (3) ◽  
pp. 209-219 ◽  
Author(s):  
Axel Brandenburg ◽  
Tuomas Multamäki
Keyword(s):  
Time Scale ◽  
Early Life ◽  
Large Scale ◽  
Reaction Diffusion ◽  
Front Propagation ◽  
Life Forms ◽  
Diffusion Time ◽  
Reaction Diffusion Equations ◽  
Deep Layers ◽  
Left And Right

Reaction-diffusion equations based on a polymerization model are solved to simulate the spreading of hypothetic left and right-handed life forms on the Earth's surface. The equations exhibit front-like behavior as is familiar from the theory of the spreading of epidemics. It is shown that the relevant time scale for achieving global homochirality is not, however, the time scale of front propagation, but the much longer global diffusion time. The process can be sped up by turbulence and large scale flows. It is speculated that, if the deep layers of the early ocean were sufficiently quiescent, there may have been the possibility of competing early life forms with opposite handedness.

Co-evolution of trace elements and life in Precambrian oceans: The pyrite edition

Geology ◽  
2020 ◽  
Vol 48 (10) ◽  
pp. 1018-1022
Author(s):  
Indrani Mukherjee ◽  
Ross R. Large
Keyword(s):  
Trace Elements ◽  
Early Life ◽  
Redox State ◽  
Major Change ◽  
Life Forms ◽  
Biological Responses ◽  
Evolution Of Life ◽  
Marked Decline ◽  
Life On Earth ◽  
Middle Proterozoic

Abstract The significance of trace elements in initiating origins and driving evolution of life on Earth is indisputable. Trace element (TE) trends in the oceans through time broadly reflect their availability and allow speculation on all possible influences on early life. A comprehensive sedimentary pyrite–TE database, covering 3000 m.y. of the Precambrian, has improved our understanding of the sequence of bio-essential TE availability in the ocean. This study probed how changing availability (and scarcity) of critical TEs in the marine environment influenced early life. The pyrite-shale matrix TE sequence shows relatively elevated concentrations of Ni, Co, Cu, and Fe, Cr, respectively, in the Archean and Paleoproterozoic. Abundances of these elements in the Archean potentially facilitated their widespread utilization by prokaryotes. The Paleoproterozoic–Mesoproterozoic saw increases in Zn and Mo but a marked decline in Ni, Co, Cu, Se, and Fe. Our data suggest the evolution of the first complex cell in the Paleoproterozoic was probably triggered by this major change in TE composition of the oceans. A decline of elements prompted alternative utilization strategies by organisms as a response to TE deficits in the middle Proterozoic. An overall increase in a multitude of elements (Ni, Co, Cu, Cr, Se, V, Mo, and P) in the Neoproterozoic and Cambrian was highly advantageous to the various micro– and macro–life forms. Without questioning the importance of macronutrients and atmosphere-ocean redox state, multi-TE availability would have induced substantial heterogenous biological responses, owing to the effects of optimal, deficient, toxic, lethal, and survival levels of TEs on life.

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