Evolution of Life

When was the Earth formed?

4.5 billion years ago

Estimated time of origin of liquid water on Earth

3.8 billion years ago

Where did the liquid water on Earth come from?

Volcanic outgassing, collisions with icy comets and it also condensized from vapor, when the surface cooled down

When were the first indications of microbial life present?

3.7 billion years ago

Which signs of life were present in seafloor hydrothermal vents?

Microfilament structures that can also be seen in modern microbes

What are stromatolites?

Fossilized structures formed by the growth of microbial mats, primarily cyanobacteria, found in sedimentary rocks that provide evidence of early microbial activity

When did molecular oxygen first appear?

2.7 billion years ago

Where did first molecular oxygen come from?

It was generated as a waste product of cyanobacterial metabolism

What are Banded Iron Formations (BIFs)?

Sedimentary rocks composed of alternating layers of iron-rich minerals and silica, formed in marine environments and indicative of past atmospheric oxygen levels

What is the reason of rash evolutionary development of eukaryotic organisms?

Aerobic metabolism allowed for more efficient energy production, supporting greater complexity and larger populations

How is Ozone formed?

Short-wave UV-radiation causes Oxygen to form free O-radicals, which create Ozone when reacting with Oxygen

Which wavelength of UV-Light is being absorbed by the Ozone shield?

Up to 300nm

The First Eucaryotic Cell Formation Hypothesis

Suggests that the nucleus formed before the endosymbiotic events, that lead to creation of mitochondria and chloroplasts

The main problem of the First Eucaryotic Cell Formation Hypothesis

It can’t explain, why Bacteria and Eucarya have similar lipids

The Second Eucaryotic Cell Formation Hypothesis

Suggests that the nucleus formation has happened after the uptake of the mitochondrial ancestor. Lipid biosynthesis genes were then transferred to the host cell and nucleus formation was necessary to handle a larger genome

C¹³ Dating Method

A radiometric dating technique used to determine the age of carbon-containing materials by measuring the ratio of carbon-13 to carbon-12 isotopes, which helps to determine the age of the organism or material

S³⁴ Dating Method

A radiometric dating technique used to determine the age of geological formations and processes by measuring the isotopic ratios of sulfur isotopes

The main feature of early Earth conditions

Reducing atmosphere

The components of early Earth Atmosphere

H₂0, CH₄, CO₂, NH₃, H₂S, FeS, HCN

The Miller/Urey Experiment

A groundbreaking experiment that simulated early Earth conditions, showing that organic compounds could be synthesized from inorganic precursors, providing insight into the origins of life

The results of Miller/Urey Experiment

10-15% of the carbon is stored in organic compounds (HCN, aldehydes, oil and tar) and 2% in amino acids. The polymerisation of HCN can produce adenine and guanine

What is the most probable place of origin of life?

Hydrothernal vents in deep sea

The main feature of ancient hydrothermal vents

The vents consist of semipermeable FeS-membranes that allow the formation of redox- and pH-gradients. The vents also produce H₂, which is crucial for supporting microbial life even to this day

The hypothesis of RNA-life

suggests that self-replicating ribonucleic acid (RNA) molecules were key to the early stages of life, functioning both as genetic material and as catalysts for biochemical reactions, since the main RNA components (base, ribose and phosphate) are easily formed abiotically

What are ribozymes?

Catalytic active RNA that can catalyze biochemical reactions and the synthesis of itself

What are the relics of the RNA-world?

Coenzyme A and vitamin B12

What is serpentinisation?

Chemical reaction between ultramafic rocks in the Earth’s mantle and water at temperatures from 150C-400C. As a result minerals and H2 are produced, which serves as “food” for bacteria