Origin of Life Models: Spontaneous Generation & More

Fossils: Definition, Types, and Chemical Remains of Ancient Life

• The word "fossil" comes from the Latin word fossilis, which means "having been dug up."
• Fossils consist of the remains of organisms located in stratified rocks that were placed in ancient times.
• The study of fossils provides information on the nature, morphology of ancient organisms, geological past, and their environments on Earth.

Types of fossils

• Fossils are found preserved in a number of types and structures.
• The preservation dictates the extent of morphological data lost during fossilization.
• Two key types of fossils are Body fossils and Trace fossils.

Body fossils

• Body fossils include a whole or part of an organism being preserved.
• The mould is among the common types of preservation of body fossils, with a shell embedded in sediment leaving an external impression known as an external mould.
• When soft tissues of an organism inside the shell decomposed, the empty space is filled with sediment, and the core forms the internal cavity of the shell itself, bearing an impression on its surface of the internal structure, known as the internal mould.

Trace fossils

• Trace fossils are animal remains that remain after their activity and movement after their lifetime.
• Preserved traces are ichnofossils or trace fossils.
• Various kinds of trace fossils exist, and larger animals leave behind footprints and smaller aquatic animals leave resting or crawling traces.
• Trails and burrows are left in soft mud by burrowing animals without appendages, and other shells and woody tissue are left in hard material boring traces by borers.
• Coprolites are animal droppings that become preserved

Chemical fossils

• Chemical fossils are signatures of organic compounds from biological origin when organisms do not leave direct physical evidence like body and trace fossils.
• Amino acids and lipid proteins may be included of the most common compounds.
• Very old rocks, including those from Archean and Proterozoic, contains chemical fossils, suggesting life originated long before organisms left physical evidences.

Other fossil types

• Derived fossils have worn and rounded surfaces, indicating their original home was in older rock beds or that they underwent different means of preservation; the rock matrix also helps differentiates the fossils from any contemporaneous fossils.
• Living fossils are fossils that range from ancient times to the present day, and have no change in primitive character
• Remaine fossils are organic materials that are rolled and abraded, accumulating over a considerable period before deposition.
• Facies fossils: assemblages of dissimilar fossils, which are controlled by environment and limited to various sedimentary environments.
• Pseudo fossils: sedimentary or tectonic structures which look like fossilized organic remains, including manganese hydroxide markings

Significance of fossils

• The value of fossils is dependent on their position in the geologic column and geographical location.
• The fossil content and their position in the geological column are dependent on each other.
• Fossils are important for the study of chronostratigraphy since purpose is to systemize a sequence of rocks to a global scale to related single standard scale, and age of strata.

Significance of fossils: Biostratigraphy

• Marine sediments feature plentiful species of fossils in certain unique sequences, with every species confined to one part in the succession, which represent it's living time.
• Paleontology and biostratigraphy can use the sequence of fauna/flora to divide geological columns into geochological unites such as era, period, epoch etc
• Contents of fossil beds can also be used to interpret historical sequence, such as with certain species used as stratified markers to characterize zones, also known as "zone fossils", including T. subbulatus and O. sakuntala

Significance of fossils: Index fossils

• Natural assemblages of fossils comprise Assemblage zones, beds or groups of beds, and the ranges of elements are displayed in range zones in the fauna and flora
• Precise time definition can be created through overlapping stratigraphical range-concurrent ranges by using overlapping stratigraphic units for multiple species
• The Index fossil correlation of rocks include animal and plant remains, and are characteristic to geologic horizons, also called guide/marker fossils

Significance of fossils: Palaeogeography study

• Study of palaeogeography uses fossil forms to show boundaries, former lands, water deltas, mountains, deserts, and shorelines.
• Fossils that imply the existence of marshy conditions also exist, including the Eohippus, while the Equus represents the presence of grasslands.
• Evidence of new land bridges can be shown through new terrestrial animals appearing that once existed during a new species in deposits form North America, such as Trinuclesis in Ordovician Europe.
• Presence of fossil fish in formations in Rajasthan indicates the Thar dessert had a vast ocean from the Arabian Sea.

Significance of fossils: Palaeoclimate and palaeoecology study

• Variation of degrees of moisture and temperature can be seen through the fossils of animals and plants. Palms indicate warmth, forams indicate a temperate climate, and corals tropical.
• Early forms of camels had deer limbs, showing limbs showing desert adaptation and climate aridity.
• Palaeoecology is the relationship between the chemistry, biology and physical environment of organisms.
• Adaptations of organisms can inform where they breed and feed, and the relationships between the environments and animals
• Insight to organisms can be seen by studying shell banks and coral reefs

Significance of fossils: The study of organic evolution

• Organic evolution is the study of fossils that support the descent with accumulative modifications.
• Fossil records are left behind for palaeontologists who study the fossil record from former organisms and how organisms become complex or decline.
• Phylogeny of animals can be analyzed through the study of fossil forms through strata, even if there is incomplete data.

Significance of fossils: Coal and petroleum uses

• Coal deposits are associated with sedimentary beds with plant fossils deposited in lake basin during the upper Paleozoic times, typically in South Africa, India etc.
• Petroleum, natural gasses are found with marine sediments and microfossils

Significance of fossils: Study of paloegeophysics and palaeoneurology

• The determination of the planet's special relationship to moon and sun involves paleogeophysics utilizing fossils.
• Wells discovered that bands form on corals that related to eartly changes or nutrient and tidal flux, with modern corals showing bands that represent days.
• Another study involves Palaeoneurology, to find intelligence ranges through endocranial moulds with the study of the end cranium

Chemical remains of ancient life

• A dead organism that decays with the sediment may leave chemical residue, also known as biomarkers.
• Biomarkers serve as key information to finding the presence of ancient life.
• More complex organisms are seen through biomarkers which are more complex than bacteria with existed 1.7 million years ago

Origin of live: Theories and modesl

• Spontaneous generation believes organisms came from nonliving matter directly
• Inorganic model believes organic molecules arose due to selection pressure, with the model carried out in 2007, and has silicate crystals and clay minerals
• Extraterrestrial model believes building blocks of live were seeded on Earth due to metorite bombardment with simple molecules
• Biochemical molecules are the Oparin-Haldane theory and they are broken down into protocells, membrane, heterotrophic system to form live
• Hydrothermal model is a recently purposed transition amino acids to DNA is said had happened through volcano and hot waters

Geological Time Scale

• The timescale for referencing conditions or events that particular happened is the Geological time scale to study about the history of Earth.
• Early geologists had no way of knowing how many time units there would be in the completed scale of geologic time; nor did they know which fossils would be useful for correlation. Therefore, the time scale grew as an uncoordinated manner, the time units were discovered an named inconsistent as they were made discovere and as the rock type. Boundaries also correspond to extinct species
• Rock layers are named after a particular regions rock exposure, using hierarchy for the division, such as eons, eras, and period

Eons and Eras

• Eons refer to the entire Earth history, The Archean period began with the formation of rocks.
• The periods represent when the sudden disappearance and similar the reproduction of animals mark

A Grand sequence

• Sedimentary sequences are examplefied with the Grand canyon, which features many rock layers named after aspracts of the canyon.
• Different layers match by the environmental aspect like the water of what the time was like to determine dating techniques

Fossilization processes and modes of fossil preservation

• Fossilization is a conversion into a fossil for both the inorganic and organic which need hard parts like the bone.
• Petrifaction or permineralization process of complete mineralization of the original structure preserves material by means of penetration of the lime.
• Recrystallization tends to organize the molecules
• Carbonization creates skeleton such as that of chitinous in the graptolites
• Normal transition from dead body to fossil is: Tissues and plants decay, hard tissues are Transport and breaked, and then hardtissues become burried and modified
• Exceptional fossils preservation examples is crucial

Hard parts and soft parts of fossils

• Fossils need to have hard parts for skeletons that provide information about an extict animals skeleton.
• The factors oxygen supplies, Temperature and Ph, material volitality, have an affect on decomposition. Therefore leading to preservation

Decay

• The processes include:
• Scavenging: larger animals
• Decay: Microbes transform tissues.
• Volatility highly influence
• Aerobic environments have microbes transform tissue.
• Anaerobic environments nitrate manganese influence them Decay is influence from many variables

Exceptional preservation and hard parts of fossils

• Fossil bearing formations of different ages are terrmed Lagerstatten. These have remarkable fossils with preserved aspects. This means it can occur in pynte phosphate
• The condtions consist of High/low burials, Organic content and rate of burial is important and can give way to the physical and chemical effects such as the diagensis of pyrite

Fossil Assemblages and transport/breakage

• Fossil Assemblages is gathering from sedimentary transport to form a horizon.
• Preservation are created through exceptionally preserved assemblages with conservation.
• Unusal condisitions of presvation result from the environment
• Breakages occurs for scavenging animals that have tolls that can influence the enviroment and result into the breakage
• They become disarticulated as they part into components or from bioerosion. Mineral and chemical properties also do this.

Burial and modification of fossils

• Animals and sediment, which may result from diagenesis, go through great scavenging from chemical hange. These happen within the environment from erosion and distortion like the carbinate which cause the shift.

Plant Preservation

• There needs to be Plant, hard, 3 dimentio preservation through mud and sand. Celluar permineralization may show great super microscopic detail through cellular permineralization while coalified is lost.
• Cementation forms the plant part from the mineral material.
• Mineralization is the same and includes diatomic cell wells

Expectional preservation sites

• There exists a need of a geological site such as a time and fauna for Edicara
• There lies a need of oraganisms, such as the small shelly shells which was important but lacked specific needs. Burgess was only 20%, making it the one of unusualness nature

Geobiology and The process and production cycles through the biosphere,

• principles and tool is the application of studies through earths tools like 1940 which carry studies at earths transform descriptive science, this applies to study earth
• Surface are supported by research on the micro control over climatic change in the ecological control. Extremophiles to improve valuable metals.

System processes and products

• This consists of the biota organisms on earth such as whale, or small items such as bacyeria that uniformily support on plant
• It will the corner stone for the darwin theory about evolution. tolerance of environmental factors is to a certain extent a distribution. and the main factors consist of both radiation.
• These will act as the continent that have great changes during tektonics cycles and how the super contienent was established.

Geobiology, The elemental and processes is for example, for carbon

• Cycles known as biogeochemical cycles show where the key elements are in the reservoirs at what form. The photosynthesis to the sugars, that create oxidizes which allow the rapid increase in fossil feuls. Sulfer, nitrogen, carbon cycle together.

Abundance and diversity

• The bizarre are microbes than fiction, that thrive with iron, uranium, and in boiling acid. This make groups have the most abundant form life in earth, a truism from the geo past.

Microbe Mineral interaction

• Microbes and Mnerals interact at all time and spatial scales, are found in earth extreme enviornment in all places found and varied, a common thread-teract the the mineral
• 2 categories are:
• BCM that the nucleation growths
• BIM resulting with the microbial metablosim. The mineral perspective includes the dissolution

The Archaean life and The fossial Record

• All living things couldn't exist before at least 100m year for Earth life. Giant asteriods would sterilize the Earth,
• Microbricds show that, as origin tell today and show carbo and photo. Stromalolites increased in size and abundance
• Isotope show, carbo, and methane,
• Molds of cells were found at the time, with the old fossils being cells
• Archaean lack fossils that represent organisms, which also contain the nuclei and chromosomes

The Transition From archean to proterzoic

• Heat flow from Earth declined As the time progressed through the Archean along with growing continent leading towards larger plates. Large plate tectonics can be determined through continental crust seeming to be define the transitional
• Geochemistry dramatic change is popular, The rigid lithosphere caused the continent Area, was a factior from mantle pluse under crust
• The radioactive was what cause a specuation at what was caused a differentation form the arch

Continental crust growth view

• An increase from a continental crust vol to 1 to 2 % at the transition point, at the time 3.2 billion years ago
• Early increase are attributed to being an island ark or massive crustal melting due to the granite and the diorite.
• The most likely answer for how that would get to the size is unkown but the granite are more like a consequence

Oxygen evolution and divisions

• An increase in olymenr with levels greatly impact the atmospheric and surface evolution in that time
• Present days cycles are that as souce are dominate on the earth and how the the ogyxgen had increased with the amount energy that it lead to.
• It involved 2 factors
• enabling Aerorobic respiration
• O3 that led to protokaryotes are those are in the environment

Precrambrian Macrofossils

• Precamrbian Marcrofosils were soft things in that point in time that Edriarce was found.
  • A unique 30 genus of species were displayed but a great number of these were flattened

THE SNOWBALL EARTH HYPOTHESIS

• The final stage, during a late Precambrian period, from 1.3 to540 mil
• Earth slow quire eveloution, led to climatic changed involing the glaciation
• Harland has pointed to the accurence glacial deopsit during the neoprotziot, and when the ancient was reconstricted to polar wandering
• Haran hypothesis was ignored and has becopnre reamxime with deposits called diamctines and were on Mounitan glacier to extend in large amounts with its sea ice to resamble ice

The snow ball theory

• There is evidence that suns were bright in the tropic. But how that can the sun be in the tropics it would be
  • That the snowbal, and the large amounts of carbon were burried drewing it down suflfucieny
• To allow glaciers which are caused by high lattduatitt
  • That the roatzion, and the poles have ben reversed to what it was so The poles at the tiem were closer

The Proterozic

The Proterozoic eon spans the time interval from 2500 to 542 million years ago. This geologic time interval encompasses about 42% of all geologic time. The Archean Eon was dominated by prokaryotic life, without multicellular organisms or sexual reproduction. What key geologic events occurred then, and what types of fossilsare found in rocks of that age? The Archean is marked by an increase The archeans major events was 6500 billion The events. This was with and an the snow ball eart

Paleozoic and Origin of terrestial life

Paleozioc :488 ma

• water to land,
• The Plants is woody to spread which ulimatley forstes at a high rates of photosynthesis and a transistions

##Origin of vertebatreds

• Vertebrate from an inverbrate had a line what are the vertebrae. Chordita that is hard to find

####Origin of the tetrapod

• The origin of the water led to tetrapods being from 4 and also bony paired fins
• The tetroapod ####Origin of the mammals
• The tetroapod have the oppssotiry for insects , however many of they have teef are in a state of having the teef
• The mesozoic era, which is the and the tetrapod and the ocean #The ceozonic

####Evoloutn of dinos The dinosaurs to the birds was from the advanxed locomotory The first dinosaur was were a -Lizard shape and that teef had an advanced pelvic with and lizard hepped diet that had led to their success.

• The mesozic period had the to become dominate
• The ocean and which are in a state of having

Mass exticiton events, Cretaceous-Tertiary Extiction Event and the recovery

Most extionctons of and they had the ocean and the The Cretaceous-Tertiary had the (200) Krt that

Explore the origin of life theories, from disproven spontaneous generation to inorganic and extraterrestrial models. Discover evidence, limitations, and key factors like meteorite bombardment and organic molecule protection. Understand the breakdown of skeletal remains on sediment surfaces.