Tuesday, November 29, 2022

How Did Life Begin Biology

Don't Miss

Speculations On Lifes Origin

What is Biology? The Characteristics of Life.

3.5 billion years ago, the first undisputed evidence of life was found and these were cyanobacteria a photosynthetic organism. Scientists have also evidence which supports that life began even earlier. But today, these organisms are credited for creating the oxygen-rich atmosphere that we have today. Fast forward a few million years and the very first eukaryotic organisms appeared on the scene. The Last Common Universal Ancestor is a speculated organism that serves as the ancestor of all organisms that have ever lived or living on earth. In other words, it could be called a progenote the hypothetical ancestor to all life on earth.

Another alternative theory to abiogenesis is the Panspermia Hypothesis. This theory states that life on the earth came from meteors and comets and other stellar bodies. These may harbour chemicals required for life such as organic compounds and water. These interstellar objects travel vast distances, and one of them may have crashed into the earth, thereby kickstarting the mechanism of life. However, this is just a speculation and there isnt enough evidence to back up this theory.

Independent Emergence On Earth

Life on Earth is based on carbon and water. Carbon provides stable frameworks for complex chemicals and can be easily extracted from the environment, especially from carbon dioxide. There is no other chemical element whose properties are similar enough to carbon’s to be called an analogue silicon, the element directly below carbon on the periodic table, does not form very many complex stable molecules, and because most of its compounds are water-insoluble and because silicon dioxide is a hard and abrasive solid in contrast to carbon dioxide at temperatures associated with living things, it would be more difficult for organisms to extract. The elements boron and phosphorus have more complex chemistries, but suffer from other limitations relative to carbon. Water is an excellent solvent and has two other useful properties: the fact that ice floats enables aquatic organisms to survive beneath it in winter and its molecules have electrically negative and positive ends, which enables it to form a wider range of compounds than other solvents can. Other good solvents, such as ammonia, are liquid only at such low temperatures that chemical reactions may be too slow to sustain life, and lack water’s other advantages. Organisms based on alternative biochemistry may, however, be possible on other planets.

Replication first: RNA world

Metabolism first: Ironsulfur world

Membranes first: Lipid world

How Do Birds And Butterflies Migrate

Some birds and butterflies migrate thousands of miles to places they have never been to before. Science does not know how they navigate. People need maps and other navigational aids to fly somewhere in a plane. Should not a highly evolved human being be better at navigating than a butterfly? Science does not know exactly how birds and butterflies navigate. If creation by God is not an option, then birds and butterflies evolved capabilities that more highly evolved creatures, humans, do not have. Evolution is about the improvement of life. Butterflies are insects, far down on the evolutionary scale. How could they have such an advanced capability that humans, the most highly evolved life, does not have?

You May Like: What Do You Need To Study Criminal Psychology

Replies To How Did Life Begin

  • John Schimonsays:

    quoting geniuses doesnt make life closer to understanding.

  • EarthlingXsays:

    Heres a paper calculating beginning of life based on increasing complexity, similar to Moors Law. Their calculation shows life started about 9.7 billion years ago.

    Life Before Earth

  • EarthlingXsays:

    Thank you for taking your time checking it.

    I dont know enough to have a decent opinion about it, just thought it might add to the discussion.

  • EarthlingXsays:

    This are things i liked about it : assumption of possibility that complex organics could self assemble in space as i recently read a paper, showing that quantum effects could enable chemistry of complex organics at temperatures much lower than required for liquid water and, IIRC, without need for water either. There is also evidence of amino acids being created in non-planetary environment, so no real news, but that other paper was talking about more complex molecules.

    idea of oil micro-capsules containing enzymes creating some kind of closed cell-like environment.

    Rest, im learning

  • Too much time is spent questioning where life came from and not enough on where its going. Fukushima is on the brink of exterminating all life in the northern hemisphere while scientists are pondering theories. How about some smart engineers getting together and entombing that thing and saving the world?

  • Olaf2says:

    Jesus what a kind of crap did you listen to.

  • John Schimonsays:

    And I know what this site is, I frequent it everyday.

  • Environmental And Evolutionary Impact Of Microbial Mats

    Molecular Cell Biology Lodish 6th.ppt

    Microbial mats are multi-layered, multi-species colonies of bacteria and other organisms that are generally only a few millimeters thick, but still contain a wide range of chemical environments, each of which favors a different set of microorganisms. To some extent each mat forms its own food chain, as the by-products of each group of microorganisms generally serve as “food” for adjacent groups.

    Stromatolites are stubby pillars built as microorganisms in mats slowly migrate upwards to avoid being smothered by sediment deposited on them by water. There has been vigorous debate about the validity of alleged fossils from before 3 Ga, with critics arguing that so-called stromatolites could have been formed by non-biological processes. In 2006, another find of stromatolites was reported from the same part of Australia as previous ones, in rocks dated to 3.5 Ga.

    Cyanobacteria have the most complete biochemical “toolkits” of all the mat-forming organisms. Hence they are the most self-sufficient of the mat organisms and were well-adapted to strike out on their own both as floating mats and as the first of the phytoplankton, providing the basis of most marine food chains.

    Read Also: What Is Cross Cultural Psychology

    Our Technology Cannot Improve Upon Nature

    There are many things in nature that our technology cannot replicate, much less improve upon. Why? Things in nature are said to be a product of chance. It seems that our technology would be able to improve upon things that happened by chance.

    Here is an example:

    I am a birdwatcher. This is something I think about often. Birds can land on a piece of wire or branch about as big around as their eyeball. Airplanes are designed by human beings, highly evolved human beings. Why cannot an intelligently designed machine do something as well as a random happenstance bird? Why cannot man design an airplane that slows down, grabs onto a perch, and remains upright? Why cannot an airplane land on something as big around as the cockpit window? Why cannot an airplane maneuver as well as a bird? If a bird is just a random chance occurrence, and humans are the most advanced life on earth, why cannot humans come up with a design that works better than a random chance?

    The Process That Created Life

    The thorniest question is the mechanism by which life began. Which of the many processes that take place in living organisms emerged first?

    One of the first ideas, popularised by biochemist Sidney Fox in the wake of the Miller-Urey experiment, was that amino acids assembled into simple proteins. In modern organisms, proteins perform a huge range of functions, including acting as enzymes that speed up essential chemical reactions. However, this proteins-first hypothesis has largely fallen out of favour.

    A much more popular notion is that life began with RNA, a close cousin of DNA, in an RNA World. RNA can carry genes and copy itself just like DNA, but it can also fold up and act as an enzyme, just like a protein. The idea was that organisms based solely on RNA arose first, and only later developed DNA and protein.

    Read Also: Which Founding Contributors To Psychology Helped Develop Behaviorism

    The Intelligent Design Movement

    According to the Darwinist model of evolution, undirected natural causes are responsible for the origin and development of life. Because Darwinist evolution is based solely on random genetic mutation, it precludes the possibility of a supernatural Creator, or any guiding intelligence, playing a role in lifes development.In spite of the incredible level of acceptance of Darwinism and evolution over the decades, however, there have always been some dissenters who rejected Charles Darwins claim that undirected natural causes could not only produce life but be responsible for the countless species and forms of life we see today.Until the mid-1980s, these other voices were largely isolated and sporadic. More recently these growing voicescategorized as the intelligent design movementhave become more focused in their pointed criticisms of Darwinist evolution. Many attempt to overturn the cultural dominance of Darwinism in both social and academic circles. Without employing the Bible as a scientific text, many intelligent-design scientists and scholars, including authors such as Phillip Johnson, Michael Behe, Charles Thaxton, Michael Denton and Stephen Meyer, have critiqued Darwinism on scientific and philosophical grounds.

    Dinosaurs Birds And Mammals

    How Did Life Begin on Earth?

    Amniotes, whose eggs can survive in dry environments, probably evolved in the Late Carboniferous period . The earliest fossils of the two surviving amniote groups, synapsids and sauropsids, date from around 313 Ma. The synapsid pelycosaurs and their descendants the therapsids are the most common land vertebrates in the best-known Permian fossil beds. However, at the time these were all in temperate zones at middle latitudes, and there is evidence that hotter, drier environments nearer the Equator were dominated by sauropsids and amphibians.

    The PermianTriassic extinction event wiped out almost all land vertebrates, as well as the great majority of other life. During the slow recovery from this catastrophe, estimated to have taken 30 million years, a previously obscure sauropsid group became the most abundant and diverse terrestrial vertebrates: a few fossils of archosauriformes have been found in Late Permian rocks, but, by the Middle Triassic, archosaurs were the dominant land vertebrates. Dinosaurs distinguished themselves from other archosaurs in the Late Triassic, and became the dominant land vertebrates of the Jurassic and Cretaceous periods .

    During the Late Jurassic, birds evolved from small, predatory theropod dinosaurs. The first birds inherited teeth and long, bony tails from their dinosaur ancestors, but some had developed horny, toothless beaks by the very Late Jurassic and short pygostyle tails by the Early Cretaceous.

    Read Also: What Is An Inhibitor Chemistry

    How Did Life Begin Texas Paleontologist Says He’s Found The Biological ‘holy Grail’

    Associate Science Editor, The Huffington Post

    Scientists know life on Earth began more than 3.8 billion years ago, but exactly how it began has long been an unanswered question.

    Now a scientist in Texas believes he has the answer.

    This is bigger than finding any dinosaur, Dr. Sankar Chatterjee, a professor of geoscience at Texas Tech University and curator of paleontology at the Museum Of Texas Tech University, said in a written statement. This is what weve all searched for–the Holy Grail of science.

    It’s long been known that the ancient earth was pummeled by asteroids, meteors and comets–and that these space rocks may have brought water and organic molecules to our planet. But Chatterjee has taken these ideas a step further. He argues that in addition to bringing water and the chemical constituents of life, the space rocks left impact craters that became “crucibles” in which the chemical reactions that ultimately gave rise to living cells took place.

    Specifically, Chatterjee believes, meteorites punched giant craters into the Earth and deposited organic materials in them. Then icy comets that crashed into Earth melted, and filled these basins with water. Additional meteorite strikes created volcanically driven geothermal vents in the Earth’s crust that heated and stirred the water.

    The resulting “primordial soup” mixed the chemicals together, leading to the formation of molecules of ever increasing complexity–and eventually life.

    And From The Literature

    “Development begins at fertilization when a sperm fuses with an ovum to form a zygote this cell is the beginning of a new human being.”Moore, Keith L., The Developing Human: Clinically Oriented Embryology, page 12, W.B. Saunders Co., 2003

    “In that fraction of a second when the chromosomes form pairs, the sex of the new child will be determined, hereditary characteristics received from each parent will be set, and a new life will have begun.”Kaluger, G., and Kaluger, M., Human Development: The Span of Life, page 28-29, The C.V. Mosby Co., 1974

    “A new individual is created when the elements of a potent sperm merge with those of a fertile ovum.”Encyclopedia Britannica, “Pregnancy,” page 968, 15th Edition, Chicago 1974

    “Development begins with fertilization, the process by which the male gamete, the sperm, and the femal gamete, the oocyte, unite to give rise to a zygote.”T.W. Sadler, Langman’s Medical Embryology, 10th edition. Philadelphia, PA: Lippincott Williams & Wilkins, 2006. p. 11

    “”Although life is a continuous process, fertilization is a critical landmark because, under ordinary circumstances, a new genetically distinct human organism is formed when the chromosomes of the male and female pronuclei blend in the oocyte.”Ronan O’Rahilly and Fabiola Müller, Human Embryology and Teratology, 3rd edition. New York: Wiley-Liss, 2001. p. 8.

    Also Check: What Is Naoh In Chemistry

    How Life Came Together

    Explanations of how the amino acids, nucleotides, and sugars were formed, how they assembled in the form of DNA and RNA, and then how these building blocks of life came to replicate themselves and acquire the enzymes to facilitate this process, are all still speculative. Many interesting ideas are being researched, however, including the deep sea vent theory,12 radioactive beach theory13 and crystal or clay theory.14Another opinion, held by Francis Crick and others, is that the only explanation for life on Earth is that it came from another planet.15 However, this type of explanation only pushes the question farther back: How did this extraterrestrial life originate? A compelling scientific explanation of the origin of life here on Earth has not yet emerged.

    While researchers have recently generated self-replicating RNA from prebiotic molecules in the laboratory,16 it is difficult to understand how RNAa notoriously unstable polymercould have supported self-replicating systems in the hostile chemical and thermal environment of early planet Earth.

    How Did Life First Emerge On Earth

    Paleontologist presents origin of life theory

    Have you ever had a mystery to solve? Like a time when you knew something happened, but you didnt really know how? Maybe you felt like you needed to find some clues to figure out what happened. Thats how scientists feel about figuring out how life got going here on Earth long ago. If you have a mystery and are curious, you start looking for clues. Scientists are doing that right now. They may not figure it all out before you are a grown up. When you get older maybe you could help find clues to this mystery as well. What kinds of clues do you think would be helpful in learning about things that happened long ago?

    Disciplinary Core Ideas

    ESS1.C: The History of Planet Earth: Some events happen very quickly others occur very slowly, over a time period much longer than one can observe.

    ESS3.A: Natural Resources: Living things need water, air, and resources from the land, and they live in places that have the things they need. Humans use natural resources for everything they do.

    Crosscutting Concepts

    Patterns: Patterns in the natural and human designed world can be observed and used as evidence.

    Big Ideas: How life got started on Earth is a mystery. Scienists are piecing together the clues to learn more about how life began on Earth.

    Boundaries: In this grade band, Earth events are described in terms of relative time rather than quantitative measurements of timescales.

    No appropriate content for this grade level. Please use the navigation arrows to switch levels.

    You May Like: Kuta Software Geometry Answer Key

    Deuterostomes And The First Vertebrates

    Most of the animals at the heart of the Cambrian explosion debate are protostomes, one of the two main groups of complex animals. The other major group, the deuterostomes, contains invertebrates such as starfish and sea urchins , as well as chordates . Many echinoderms have hard calcite “shells,” which are fairly common from the Early Cambrian small shelly fauna onwards. Other deuterostome groups are soft-bodied, and most of the significant Cambrian deuterostome fossils come from the Chengjiang fauna, a lagerstätte in China. The chordates are another major deuterostome group: animals with a distinct dorsal nerve cord. Chordates include soft-bodied invertebrates such as tunicates as well as vertebratesanimals with a backbone. While tunicate fossils predate the Cambrian explosion, the Chengjiang fossils Haikouichthys and Myllokunmingia appear to be true vertebrates, and Haikouichthys had distinct vertebrae, which may have been slightly mineralized. Vertebrates with jaws, such as the acanthodians, first appeared in the Late Ordovician.

    Molecules Of Life Met On Clay

    The first molecules of life might have met on clay, according to an idea elaborated by organic chemist Alexander Graham Cairns-Smith at the University of Glasgow in Scotland. Cairns-Smith proposed in his 1985 controversial book Seven Clues to the Origin of Life” , that clay crystals preserve their structure as they grow and stick together to form areas exposed to different environments and trap other molecules along the way and organise them into patterns much like our genes do now.

    Is there water on Mars?

    The main role of DNA is to store information on how other molecules should be arranged. Genetic sequences in DNA are essentially instructions on how amino acids should be arranged in proteins. Cairns-Smith suggests that mineral crystals in clay could have arranged organic molecules into organized patterns. After a while, organic molecules took over this job and organized themselves.

    Although Cairns-Smith’s theory certainly gave scientists food for thought in the 1980s, it has still not been widely accepted by the scientific community.

    Don’t Miss: How Is Chemistry Used In Everyday Life

    More articles

    Popular Articles