Lifeboat Foundation

The origin and early evolution of life is generally studied under two different paradigms: bottom up and top down. Prebiotic chemistry and early Earth geochemistry allow researchers to explore possible origin of life scenarios. But for these “bottom–up” approaches, even successful experiments only amount to a proof of principle. On the other hand, “top–down” research on early evolutionary history is able to provide a historical account about ancient organisms, but is unable to investigate stages that occurred during and just after the origin of life. Here, we consider ancient electron transport chains (ETCs) as a potential bridge between early evolutionary history and a protocellular stage that preceded it. Current phylogenetic evidence suggests that ancestors of several extant ETC components were present at least as late as the last universal common ancestor of life. In addition, recent experiments have shown that some aspects of modern ETCs can be replicated by minerals, protocells, or organic cofactors in the absence of biological proteins. Here, we discuss the diversity of ETCs and other forms of chemiosmotic energy conservation, describe current work on the early evolution of membrane bioenergetics, and advocate for several lines of research to enhance this understanding by pairing top–down and bottom–up approaches.

Researchers led by a team at UT Southwestern Medical Center have identified cellular and molecular features of the brain that set modern humans apart from their closest primate relatives and ancient human ancestors. The findings, published in Nature, offer new insights into human brain evolution.

“Most evolutionary studies on the human brain have focused on neurons because this cell type was thought to be responsible for our intelligence and enhanced cognitive abilities. This study gives us a renewed appreciation for other cells involved in brain function and the role they have played both in advancing cognition and our susceptibility to a number of cognitive diseases,” said study leader Genevieve Konopka, Ph.D., Professor of Neuroscience and a member of the Peter O’Donnell Jr. Brain Institute at UT Southwestern.

Since ancient times, people have been curious about what gives humans abilities that other animals don’t have, such as speech and language, Dr. Konopka explained. A range of previous studies have sought to answer this question by examining brain anatomy or performing genetic or molecular studies on whole brains or sections, experiments that provide a view of thousands of cells at a time.

An ancient skull dating back 300,000 years is unlike any other premodern human fossil ever found, potentially pointing to a new branch in the human family tree, according to new research.

An international team of researchers from China, Spain and the United Kingdom unearthed the skull — specifically the mandible, or lower jaw — in the Hualongdong region of eastern China in 2015, along with 15 other specimens, all thought to originate from the late Middle Pleistocene period.

Scientists believe the late Middle Pleistocene, which started around 300,000 years ago, was a pivotal period for the evolution of hominins — species that are regarded as human or closely related — including modern humans.

An interdisciplinary team of mathematicians, engineers, physicists, and medical scientists have uncovered an unexpected link between pure mathematics and genetics, that reveals key insights into the structure of neutral mutations and the evolution of organisms.

Number theory, the study of the properties of positive integers, is perhaps the purest form of mathematics. At first sight, it may seem far too abstract to apply to the natural world. In fact, the influential American number theorist Leonard Dickson wrote ‘Thank God that number theory is unsullied by any application.’

And yet, again and again, number theory finds unexpected applications in science and engineering, from leaf angles that (almost) universally follow the Fibonacci sequence, to modern encryption techniques based on factoring prime numbers. Now, researchers have demonstrated an unexpected link between number theory and evolutionary genetics.

The discipline of systems chemistry deals with the analysis and synthesis of various autocatalytic systems and is therefore closely related to the study of the origin of life, since it investigates systems that can be considered as a transition between chemical and biological evolution: more complex than simple molecules, but simpler than living cells.

Tibor Gánti described the theory of self-replicating microspheres as early as 1978. These still lacked genetic material, but concealed within their membranes an autocatalytic metabolic network of small molecules, isolated (compartmentalized) within their membranes.

As the autocatalytic process takes place, the membrane-building material is also produced, leading to the division of the sphere. This system may appear to be a living cell, and although it lacks genetic material, this can only be verified experimentally. These microspheres can be considered as “infrabiological” chemical systems, since they do not reach the level of biological organization, but they exceed the complexity of normal chemical reactions.

One of the most actively debated questions about human and non-human culture is this: under what circumstances might we expect culture, in particular the ability to learn from one another, to be favored by natural selection? Researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have developed a simulation model of the evolution of social learning. They showed that the interplay between learning, memory and forgetting broadens the conditions under which we expect to see social learning to evolve.

Social learning is typically thought to be most beneficial when the environments in which individuals live change quite slowly – they can safely learn tried and tested information from one another and it does not go out of date quickly. Innovating brand-new information, on the other hand, is thought to be useful in dynamic and rapidly changing environments.

Researchers Madeleine Ammar, Laurel Fogarty and Anne Kandler at the Max Planck Institute for Evolutionary Anthropology developed an agent-based simulation model of the evolution of social learning that incorporated the ways in which animals might remember, forget, and share crucial pieces of information throughout their lives. They asked: when do the agents want to learn from others? When is it best to forget or retain information that they have learned? When is it best to innovate?

“I view string theory as the most promising way to quantize matter and gravity in a unified way. We need both quantum gravity and we need unification and a quantization of gravity. One of the reasons why string theory is promising is that there are no singularities associated with those singularities are the same type that they offer point particles.” — Robert Brandenberger.

In this thought-provoking conversation, my grad school mentor, Robert Brandenberger shares his unique perspective on various cosmological concepts. He challenges the notion of the fundamental nature of the Planck length, questioning its significance and delving into intriguing debates surrounding its importance in our understanding of the universe. He also addresses some eyebrow-raising claims made by Elon Musk about the limitations imposed by the Planck scale on the number of digits of pi.

Continue reading “Unseen Fluctuations: Challenging Inflation | Robert Brandenberger” »

Bacterial cells can easily share genes with one another, and have a few ways to do so. Viruses called bacteriophages infect bacterial cells, and they can also transfer genes between bacterial cells in a process known as transduction. Often, the genes that are being shared confer resistance to a drug, and once a bacterial cell gains the ability, antibiotic resistance can easily spread through populations of microbial cells. Now scientists have discovered another mechanism that bacteria use to share genes, and it can help microbes evolve even faster than we knew. The findings have been reported in Cell.

There are three types of transduction that we now know about: generalized, specialized, and lateral. The newly revealed mechanism is called lateral cotransduction. It is about as rapid as lateral transduction, which itself is far faster than generalized transduction. However, the study indicated that lateral cotransduction is more complex and versatile than the other modes of transduction. Lateral transduction happens when phages that have integrated into bacterial genomes are reactivated, and trigger reproduction in the lytic cycle; but lateral cotransduction can while new bacterial cells are being infected, and during the reactivation process.

Evolution doesn’t fix things — it reinvents them. A biologist explains.