- Early theories proposed that life arose spontaneously from non-living matter, but experiments disproved this. Miller and Urey's experiment showed that amino acids could form from simple gases on the early Earth. Sidney Fox produced early cell-like structures called protocells and microspheres in experiments. Endosymbiotic theory proposes that mitochondria and chloroplasts originated as internalized prokaryotes. Early life on Earth was likely anaerobic prokaryotic heterotrophs that evolved into autotrophs as organic compounds became scarce. Archaebacteria and cyanobacteria-like organisms were early photosynthetic life forms.
Presentation is about the "Origin of Life". Many theories being proposed to clearly explains how does Life actually came into existence on our planet Earth.
Presentation is about the "Origin of Life". Many theories being proposed to clearly explains how does Life actually came into existence on our planet Earth.
Origin Of Life: Are we here by chance? Theories on origin of life, Scientific and Special Creation. Different Theories of life's origin including Aristotle's theory, Pasteur, Redi and Leuwenhook experiment, Abiogenesis, etc.
Fossils and its evolutionary significance.
Origin Of Life: Are we here by chance? Theories on origin of life, Scientific and Special Creation. Different Theories of life's origin including Aristotle's theory, Pasteur, Redi and Leuwenhook experiment, Abiogenesis, etc.
Fossils and its evolutionary significance.
Life, living matter are those that shows certain attributes that include responsiveness, growth, metabolism, energy transformation and reproduction.
In biology origin of life or abiogenesis is the natural process by which life has arisen from non-living matter, such as simple organic compounds.
It means the emergence of heritable and evolvable self-reproduction.
It is a complex subject and oftentimes controversial.
Several attempts have been made from time to time to explain the origin of life on earth.
There are several theories which offer their own explanation on the possible mechanism of origin of life.
Origin of life-where did life come fromArosek Padhi
this chapter prompts you to wonder where did life as we know it came from. this is a presentation from Dr.Tithi Parija (asst professor) from KIIT school of biotechnology including different theories from different thinkers and scientists
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
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Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
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Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
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Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
1. Early Earth and
Theories on the Origins of Life!
In your investigation today, you will
explore the early experiments with life
on earth and then create proto-cells in
the laboratory!
2. Earth History
Earth History:
• Evolution is studied using concepts about earth history. The earth is
between 4.3 and 4.5 billion years old.
• Approximately 3.9 billion years ago, the surface was likely cool enough for
water vapor to condense. (Oceans formed.)
• Many of these events and organisms are recorded on the
geologic time scale.
• As geologists provided evidence
about the age of the earth and the
rate at which changes happened,
biologists began to suspect that life,
and life forms also changed over the
same time.
Geologic and evolutionary change is
a long and slow process.
People wondered, how did life arise?
http://www.youtube.com/watch?v=QDqsk
3. First Ideas:
Spontaneous Generation
• Aristotle about 2300 years ago argued that air
provided a vital life force that could produce
life from nonliving substances. This is called
spontaneous generation.
• The idea of spontaneous generation prevailed
for thousands of years.
– What do you think could have been the implication
of this theory on ideas of human reproduction?
• This idea was not formally tested until the
1700s.
4. Key Scientists – Origin of Life
Francesco Redi (1626-1697)
• First strike against spontaneous
generation, his work:
• Experimental Group: Covered jars with
meat = NO maggots
• Control Group: Meat in uncovered jars
= maggots
• Conclusion: Only flies where there are
maggots AND only maggots where
there had been flies… flies must come
from flies.
• It was concluded and believed they
were a product of spontaneous
generation from a “vital force” or life
force in the air.
• *As the microscope became a widely
used tool for scientists, microorganisms
were seen everywhere.
Remember, around 1678, Anton van
Leeuwenhoek observed “animalcules”
in water. We now know that these are
protozoa.
What do you think people thought this
“vital force” might be?
5.
6. Key Scientists – Origin of Life
Lazzaro Spallanzani (1729-1799)
• Experimental Group: Boiled meat
broth and sealed it in flasks = no
microorganisms
• Control Group: Boiled meat broth,
unsealed flask=microorganisms.
• Conclusion: Only had presence of
microorganisms when they had
access to the broth.
• *His doubters claimed he had killed
the “vital force” in the air when he
boiled the broth and it could then not
generate life.
It was convincing enough to keep the
belief of spontaneous generation
going for another 100 years!
Why do you think when presented
with scientific evidence, that society
still clung to the idea of spontaneous
generation?
7. Louis Pasteur (1822-1895)
• Experiment: Boiled broth and enclosed it
in an “S” curved neck flask. It was open
and exposed to air, however not directly.
Exposed for 1 year, no microorganisms;
Removed “S” curve and exposed it for 1
day! = microorganisms
• Conclusion: Spontaneous generation was
disproved and biogenesis theory was
substantiated. (Confirmed, make real or
actuated) Contamination came from other
microorganisms, not “air”.
• Modern biologists support biogenesis, the
idea that “living organisms only come
from other living organisms.”
• That then brings up the question of how
life began on Planet Earth.
• If Life can only come from life, we know at
some point there had to be a start to
“life”…
– Where would you start looking for
early life?
Key Scientists – Origin of Life
8. Key Scientists – Origin of Life
Alexander Oparin (1894-1980)
NO EXPERIMENTS!!
• Earth’s early atmosphere: HCN, CO2,
CO, N, H, S, HOH
• 1936 - Stated that the earliest living
organisms on earth were simple
heterotrophs (organisms that cannot
make their own food)
• Knew these elements (in the form of
various gases) were present in the
earth’s early atmosphere.
• When heated (geologic activity) they
might form organic compounds.
• Once condensed these compounds
would be in earth’s water bodies.
• Oparin: “Life arose from the oceans.”
• He believed that energy from lightning
and the sun can spark chemical
reactions to create macromolecules like
proteins.
Oparin’s Ideas:
a. Heterotrophs ate the
organic molecules in their
environment until the food
sources were very scarce b.
Organisms needed another
source of energy
c. Autotrophs evolved
(organisms that can make
their own food source)
d. Oxygen became
prevalent in environment
e. Cellular Respiration
possible
f. Eukaryotes evolved
9. Formation of Organic Compounds
• Stanley Miller (1930- ) and
• Harold Urey (1893-1981)
• Miller & Urey’s experiment:
• Mixtures of the organic compounds
necessary for life could have arisen from
simpler compounds present on primitive
earth.
• C, H, N, O all known to exist on earth
since the planet was formed. How did
they turn into the fundamental organic
compounds we know today?
– Used Oparin’s concept and designed a
contained experiment.
– Lightning with atmospheric gases created
amino acids and eventually life!
• 1950’s, amino acids heated without oxygen,
they formed AMINO ACIDS !!
– Why is this significant?
• Same with ATP and nucleic acids!
10. Key Scientists – Origin of Life
Sidney Fox (1912- 1998)
• -Studied the development of the first cells; found
structures that have some cell life characteristics.
• Microspheres – microscopic droplet enclosed by a
membrane of organic molecules. (Predominantly
proteins.)
• They can form buds, split and take up certain
substances from surroundings.
• Sydney Fox produced protocells by heating
solutions of amino acids.
• Coacervates – small organic droplet formed by
different types of organic molecules.
• They can grow and take up substances from
surroundings. (lipid bi-layer)
• NOTE: These are NOT ALIVE no heredity,
instead of reproduction, they form spontaneously
under proper conditions.
• Remember back to the Ecology unit, what are
some of the criteria to be considered living?
• What is something else you know of that is not
considered to be alive? Coacervates
Microspheres
11. Key Scientists –
Origin of Life
• Lynn Margulis (1938- )
• Conducted experiments in the 1960’s
• Evidence:
– 1. Mitochondria and Chloroplast
DNA is similar to bacterial DNA.
– 2. Mitochondria and Chloroplasts
have ribosomes who size and
structure resemble bacteria.
– 3. Mitochondria and Chloroplasts
reproduce by binary fission like
bacteria.
• She determined the endosymbiont
theory that ancient prokaryotes
became the first cellular organelles.
• This is significant because this was
one of the first driving forces of the
theory of evolution!
12. The Evolution of Cells
• 1st
cells were prokaryotic heterotrophs.
Chemosynthetic bacteria came next like
archaebacteria.
• Photosynthetic cells came later and added oxygen
and the ozone to the atmosphere.
• Allowed for eukaryotes because the new ozone
layer protected from UV rays and oxygen allowed
for aerobic respiration.
13. Origin of Eukaryotic Cells
• Endosymbiont Theory: Eukaryotic
cells arose from living communities
formed by prokaryotic organisms.
• The evolution towards eukaryotic
cells began between 1.5 and 2
billion years ago in what is known
as “endosymbiosis”: an internal,
mutually beneficial relationship.
• Small aerobic prokaryotes are
thought to have entered and lived
inside larger anaerobic
prokaryotes. Later additional
small photosynthetic prokaryotes
are also thought to have entered
and lived inside.
• This is huge! Chloroplasts!!
Mitochondria!!
What is some evidence that you know of
that would lead you to think that
chloroplasts and mitochondria are
unrelated to our genetic history?
14.
15.
16. Early Life on Earth: What we know
now!Early Life on Earth:
• It is known that at the beginning there was little to no oxygen available in
the earth’s atmosphere. All living things must have been anaerobic.
• The small size of the microfossils found indicates early organisms were
prokaryotes. Likely these were heterotrophs (does not make their own
food) that ate spontaneously formed organic compounds.
• Supply and Demand: as the supply of
these compounds became scarce, it
became necessary to evolve.
• Became Autotrophs (can make own
food).
17. Early Life on Earth: What we know
now!
- They learned to use chemosynthesis: CO2 is the
carbon source for needed organic molecules,
energy is obtained through chemical oxidation of
inorganic molecules.
• The “archaebacteria” of today are likely similar organisms to those early life
forms.
• Archaebacterium – Kingdom of unicellular organisms that live in anaerobic
marine sediments.
• Oxygen, as it became present in the atmosphere was often harmful to early
unicellular organisms, but by 3.5 billion years ago, some life forms had become
photosynthetic and oxygen in the atmosphere increased.
• Evidence of a group similar to the cyanobacteria of today;
Cyanobacteria – (blue green) a group of
photosynthetic unicellular prokaryotes.