Lifeboat Foundation

How life emerged from simple non-life chemicals on the ancient Earth is one of the greatest mysteries in biology. The gene expression system of extant life is based on the interdependence between multiple molecular species (DNA, RNA, and proteins). While DNA is mainly used as genetic material and proteins as functional molecules in modern biology, RNA serves as both genetic material and enzymes (ribozymes). Thus, the evolution of life may have begun with the birth of a ribozyme that replicated itself (the RNA world hypothesis), and proteins and DNA joined later. However, the complete self-replication of ribozymes from monomeric substrates has not yet been demonstrated experimentally, due to their limited activity and stability. In contrast, peptides are more chemically stable and are considered to have existed on the ancient Earth, leading to the hypothesis of RNA-peptide co-evolution from the very beginning. Our group and collaborators recently demonstrated that peptides with both hydrophobic and cationic moieties (e.g., KKVVVVVV) form β-amyloid aggregates that adsorb RNA and enhance RNA synthesis by an artificial RNA polymerase ribozyme and a simple peptide with only seven amino acid types (especially rich in valine and lysine) can fold into the ancient β-barrel conserved in various enzymes, including the core of cellular RNA polymerases. These findings, together with recent reports from other groups, suggest that simple prebiotic peptides could have supported the ancient RNA-based replication system, gradually folded into RNA-binding proteins, and eventually evolved into complex proteins like RNA polymerase.

Keywords: RNA world; ancient proteins; central dogma; origin of life; peptide.

© 2023 Japanese Society of Developmental Biologists.

An RNA-dependent RNA polymerase ribozyme that was highly optimized through in vitro evolution for the ability to copy a broad range of template sequences exhibits promiscuity toward other nucleic acids and nucleic acid analogues, including DNA, threose nucleic acid (TNA), and arabinose nucleic acid (ANA). By operating on various RNA templates, the ribozyme catalyzes multiple successive additions of DNA, TNA, or ANA monomers, although with reduced efficiency compared to RNA monomers. The ribozyme can also copy DNA or TNA templates to complementary RNAs, and to a lesser extent it can operate when both the template and product strands are composed of DNA, TNA, or ANA. These results suggest that polymerase ribozymes, which are thought to have replicated RNA genomes during the early history of life, could have transferred RNA-based genetic information to and from DNA, enabling the emergence of DNA genomes prior to the emergence of proteins. In addition, genetic systems based on nucleic acid-like molecules, which have been proposed as precursors or contemporaries of RNA-based life, could have been operated upon by a promiscuous polymerase ribozyme, thus enabling the evolutionary transition between early genetic systems.

Keywords: RNA world; XNA; origins of life; polymerase; reverse transcriptase; ribozyme.

Genetic information storage and processing rely on just two polymers, DNA and RNA, yet whether their role reflects evolutionary history or fundamental functional constraints is currently unknown. With the use of polymerase evolution and design, we show that genetic information can be stored in and recovered from six alternative genetic polymers based on simple nucleic acid architectures not found in nature [xeno-nucleic acids (XNAs)]. We also select XNA aptamers, which bind their targets with high affinity and specificity, demonstrating that beyond heredity, specific XNAs have the capacity for Darwinian evolution and folding into defined structures. Thus, heredity and evolution, two hallmarks of life, are not limited to DNA and RNA but are likely to be emergent properties of polymers capable of information storage.

A new catalog allows astronomers to trace the evolution of a star’s death.

To understand helpless human babies, our big brains and oddly involved dads, look to the evolution of birds not mammals by Antone Martinho-Truswell + BIO.

(Visit: http://www.uctv.tv/)
1:39 — Understanding Primate Brain Development Using Stem Cell Systems — Rick Livesey.
18:58 — Human-Specific Genes and Neocortex Expansion in Development and Evolution — Wieland Huttner.
37:17 — Cellular and Molecular Features of Human Brain Expansion and Evolution — Arnold Kriegstein.

The human brain is one of, if not the most important factor that distinguishes our species from all others. Three experts explore the use of stem cells in understanding the primate brain, genes that guided the evolution of the human brain, and the features that enabled the expansion of human neural characteristics. Recorded on 09/29/2017. Series: “CARTA — Center for Academic Research and Training in Anthropogeny” [11/2017] [Show ID: 32927].

A research team led by the German Cancer Research Center in Heidelberg, Germany, has discovered that the genetic sequence of a tumor can be read like a molecular clock, traced back to its most recent common ancestor cell. Extracting the duration of tumor evolution can give an accurate predictor of neuroblastoma outcomes.

In a paper published in Nature Genetics titled “Neuroblastoma arises in early fetal development and its evolutionary duration predicts outcome,” the team details the steps they took in identifying a genomic clock tested against a whole genome sequenced population combined with analysis and mathematical modeling, to identify evolution markers, traceability and a likely origin point of infant neuroblastomas.

Cancer cells start out life as heroic healthy tissues, with the sort of all for one, one for all, throw yourself on a grenade to save your mates–type attitude that is taking place throughout the body every day. At some point, something goes wrong, and a good cell goes bad.

Humans have a different kind of intelligence that has evolved only once throughout the whole history of life. Thus, we wrongly believe that humans are the most evolved species, and other creatures are at lower levels of evolution. The reality is that under any conditions, only the fittest survive. The definition of ‘fittest’ differs in each environment and condition, and so do the means for the survival of the fittest.

Learn more about what banged, and was it big?

The ability to learn and form memories allows animals to adapt their behavior based on previous experiences. Associative learning, the process through which organisms learn about the relationship between two distinct events, has been extensively studied in various animal taxa. However, the existence of associative learning, prior to the emergence of centralized nervous systems in bilaterian animals, remains unclear. Cnidarians such as sea anemones or jellyfish possess a nerve net, which lacks centralization. As the sister group to bilaterians, they are particularly well suited for studying the evolution of nervous system functions. Here, we probe the capacity of the starlet sea anemone Nematostella vectensis to form associative memories by using a classical conditioning approach. We developed a protocol combining light as the conditioned stimulus with an electric shock as the aversive unconditioned stimulus. After repetitive training, animals exhibited a conditioned response to light alone—indicating that they learned the association. In contrast, all control conditions did not form associative memories. Besides shedding light on an aspect of cnidarian behavior, these results root associative learning before the emergence of NS centralization in the metazoan lineage and raise fundamental questions about the origin and evolution of cognition in brainless animals.