Geology and Earth's History Quiz

General Education Biology - BSC 1005

• Course is about the beginning of life.
• Two philosophical approaches to life and human evolution are presented: Creationist (religious) and Evolutionist (scientific).
• Creationist view: No changes since the beginning of life and humanity (Adam and Eve).
• Evolutionist view: Continuous evolution of life and humanity.
• The Creation of Adam by Michelangelo (1512) is shown.
• The cause of the loss of paradise and birth of Earth is discussed around the apple (Malus pumila).
• Greek Christians used the fig as the forbidden fruit.
• No visual representations of an apple as the forbidden fruit before the early Western Middle Ages.
• There is no hint about the forbidden fruit from the rabbinic debates.
• The word malum, which means "evil," was confused with the word malum, which meant "apple."

The Changing Environment: Earth's Geological Timescale

• Nearly all natural science branches have contributed to understanding Earth's past, characterized by constant geological and biological evolution.
• The Geological Time Scale (GTS) shows spans of time from Earth's beginning to the present.
• GTS divides time into four great eons, starting 4,540 Ma (million years ago) with the formation of the planet.
• Earth formed approximately 4.54 billion years ago (Ga).
• Volcanism and the accretion from the solar nebula formed the primordial atmosphere and the ocean.
• The early atmosphere lacked free oxygen.
• Pre-Cambrian Period contains more than 80% of Earth's entire history. This is broken down into three eras: Hadean, Archean, and Proterozoic.

When did Life Began? Transcendent Precambrian Events

• Life arose from a chemical process, assembling simple elements and compounds into complex molecules.
• Photosynthesis, first performed by cyanobacteria, is a critical event that provided energy for almost all life on Earth.
• Free oxygen came into existence due to photosynthesis.
• Cyanobacteria evolved into chloroplasts, becoming the origin of plants.
• The earliest evidence of life, fossilized mats of cyanobacteria called Stromatolites in Greenland, is 3.7 Ga.
• Scientists believe life itself may have begun before this date, with potential hints found in 4.1 Ga zircons.

Cyanobacteria and Chloroplast

• All initial life forms were unicellular (prokaryotes).
• Eukaryotes (multicellular organisms with a nucleus) are benefited from the increase in atmospheric oxygen.
• Endosymbiotic relationships with cyanobacteria allowed algae (and later plants) to perform photosynthesis.

Cyanobacteria and O2

• A graph shows the rise of atmospheric oxygen over time, correlated with the evolution of cyanobacteria. This is known as the "Oxygen revolution."

The Cambrian Explosion

• A relatively short evolutionary event beginning around 542 million years ago.
• It lasted approximately 20-25 million years.
• A burst of diversification of many modern metazoan phyla, including 5 million new species.
• The event was accompanied by diversification in other organisms.

Theories About the Beginning of Life

• Panspermia: Theory that life appeared elsewhere in space and was brought to Earth.
• Abiogenesis: Theory that life arose from non-living matter on Earth through gradual, self-replicating processes and increasing complexity in a process not externally directed.
• Oparin's theory considers how simple compounds developed into more complex structures on Earth.

Stanley Miller and Harold Urey Experiments

• Simulated the conditions of early Earth (methane, ammonia, hydrogen, water vapor).
• Used an electric spark to mimic lightning storms to produce organic molecules.
• Demonstrated how organic molecules could arise in early Earth conditions.

Evolution of Life: The Last Universal Common Ancestor (LUCA)

• LUCA is the last universal common ancestor of all life forms.
• Evolution of metabolic pathways occurred from the Earth's formation(4.5 billion years ago), followed by prebiotic chemistry that evolved from chemicals and eventually led to the first RNA/DNA.

DNA: The Language of Life

• DNA is deoxyribonucleic acid and a self replicating material in nearly all living organisms.
• DNA is the main constituent of chromosomes and the carrier of genetic information.
• The genetic code is the correspondence between the 20 amino acids from more than 500 existing in nature, to the 61 types of messenger RNA triplets (codons) that specify them. Codons specify the same amino acids across all living organisms, this is known as universality.

Transcription and Translation

• Transcription is the process of converting DNA information into mRNA.
• Translation is the process of decoding mRNA information to create proteins from amino acids.

The Mitochondria: The Power Plant

• Mitochondria provide energy for cellular activities.
• Mitochondria are the "powerhouse" of the cell.

Endosymbiosis and Energy Transformation

• Endosymbiosis is the theory that eukaryotic organelles (mitochondria and chloroplasts) evolved from prokaryotic cells.
• Eukaryotic cells engulfed aerobic heterotrophic prokaryotes, which became mitochondria, and photosynthetic prokaryotes, which became chloroplasts.

The Mitochondria and the Chloroplast: Theory of Endosymbiosis

• Mitochondria and chloroplasts have own DNA and ribosomes, separated from the rest of the cell.
• Mitochondria originated from aerobic prokaryotes.
• Chloroplasts originated from photosynthetic prokaryotes.

Overview of Cellular Respiration

• Glucose is broken down into ATP (energy) through glycolysis and the Krebs cycle.

Binary Fission in Chloroplast and Mitochondria

• A form of asexual reproduction, creating two identical cells from one cell.
• Mitochondrial DNA replication occurs prior to division, ensuring each daughter cell inherits a copy.

Nuclear DNA and Chloroplast and Mitochondrial DNA

• Nuclear DNA is inherited from ancestral organisms and contains much more genetic information than that found in Mitochondria or Chloroplast DNA.
• Mitochondria and chloroplasts were acquired via endocytosis and still carry their own DNA.

Human Mitochondrial DNA Origin

• Mitochondrial DNA is inherited exclusively from the mother.
• Nuclear DNA is inherited from both parents.

How "Human" Are We?

• Humans have trillions of cells, and a much larger number of Bacteria and Mitochondria.

How Human Are We?

• Human tissues are composed of cells: muscle, epithelial, connective, and nervous tissues, which contain about 37 trillion cells.
• A human body also contains about 39 trillion bacteria.
• The average human cell has around 100 mitochondria, totaling roughly 3,736 trillion mitochondrial cells in a body.

The Genetic Code

• The genetic code is the correspondence between the 20 amino acids and the 61 different types of messenger RNA triplets (codons) that specify them.
• The genetic code is universal, meaning the same codons specify the same amino acids in all living organisms. This is exploited to make proteins for humans in bacteria.

Land Plants: Evolution of Plants

• Plants have evolved over millions of years from green algae.
• Seedless plants evolved vascular tissue and moved onto land.
• Seed plants evolved seeds and continued their evolution onto the land.

The First to Take Flight (Arthropods)

• The first land animals were arthropods (a type of invertebrate).
• Insects, another type of arthropod, soon followed and became quite abundant.
• Arthropods were the only land animals for millions of years following their evolution.

Vertebrates onto Land

• The first chordates were fish that evolved from worms.
• Vertebrates developed long neurons and bony vertebrae for better brain to tail signal transmission, which led to success for fish and other animals.
• Lobe-finned fishes developed into 4-limbed vertebrates (tetrapods) that moved onto land.

Evolution of Primates

• Primates evolved from a common primate ancestor.
• The evolutionary tree displays the lineages in primate evolution.

Main Principle of Evolution

• Phenotype = Genotype x Environment (What you see = Genetic x Environmental influences).
• The environment plays a role in determining the phenotype.

Environment Defines Traits: Morphological Adaptation to Same Aquatic Environments

• Similar environments can result in similar adaptations for organisms. Whales and dolphins (mammals) and sharks (fish) are examples of organisms that have evolved similar traits to live in the same environment.

Evolution of Homininae

• The evolution of human ancestors to modern humans.