Mini Exam 1 Flashcards
(64 cards)
When did life on Earth begin?
Life on Earth began approximately 3.5-4 billion years ago with simple single-celled organisms
When was the Great Oxidation Event?
The Great Oxidation Event (~2.4 billion years ago) was when photosynthesizing cyanobacteria started producing oxygen, transforming Earth’s atmosphere and enabling aerobic life.
When was the Cambrain Explosion?
The Cambrain Explosion (~540 million years ago) was a period of rapid diversification where many of the major animal phyla first appeared.
What major event allowed organisms to colonize land?
Around 450 million years ago, plants, arthropods, and vertebrates moved onto land drastically changing ecosystems.
What are mass extinction events, and name two major examples.
Mass extinction events wipe out large percentages of species. Two examples are the Permian-Triassic extinction (~252 million years ago) and the Cretaceous-Paleogene extinction (~66 million years ago)
How does natural selection drive evolution?
Natural selection drives evolution by allowing organisms with beneficial genetic mutations to survive and reproduce, leading to adaptation and speciation.
What has varied over time in Earth’s history?
Biodiversity, atmospheroc compostition, climate, geography, and ecosysyem dynamics have all varied throughout Earth’s history.
How was the atmospheric composition changed during Earth’s history?
The atmosphere has evolved, notably with the increase of oxygen during the Great Oxidatijon Event and the more recent rise in CO2 due to human activity.
What are the main drivers of change in the history of life?
Geological and climate factors, biological innovations, mass extinctions, and co-evolutionary relationships are the main drivers of change.
How has plate tectonics influenced life on Earth?
Plate tectonics caused continental drift, altering habitats, species distributions, and the evolution of life.
How has climate change influenced life on Earth?
Climate change, such as ice ages and warm periods, has led to significant shifts in ecosystems, species extinction, and the rise of new species.
What role did evolution of photosynthesis play in the history of life?
Photosynthesis, especially oxygen-producing photosynthesis, was key in transforming Earth’s atmosphere and allowing aerobic organisms to evolve.
What is adaptive radiation, and when does it usually occur?
Adaptive radiation is the rapid diversification of species to fill ecological niches, often occuring after mass extinction events.
What is the Anthropocene?
The Anthropocene is the current geological epoch where human activity is the dominant influence on the Earth’s climate and ecosystems.
What are some characteristics of the Anthropocene?
The Anthropocene is characterized by climate change, mass extinctions, land use changes, and widespread pollution driven by human activities.
How is human activity contributing to a sixth mass extinction?
Human activities, such as habitat destruction, pollution, and overexploitation, are causing species to disappear at rates much higher than the natural background rate.
How has land use changed in the Anthropocene?
Agriculture, urbanization, deforestation, and habitat fragmentation have drastically altered ecosystem, reducing biodiversity.
What are the implication of the Anthropocene?
The Anthropocene raises concerns about sustainability, biodiversity loss, and long-term ecological impacts, emphasizing the need to address human-induced changes.
What is evolution?
change in genetic composition of a population over time
POPULATIONS EVOLVE, INDIVIDUALS DO NOT
What is natural selection?
Natural selection is the process where organisms with favorable traits are more likely to survive and reproduce, passing those traits to future generations
What is genetic drift?
Involves random changes in allele frequencies in a population, often having a more significant effect in small populations
What is gene flow?
Gene flow is the transfer of genetic material (alleles) between populations, which can introduce new genetic variations to a population
What is a mutation?
Change in the DNA sequence that can introduce new genetic variation (alleles) into a population
What are alleles?
Alleles are different versions of a gene that can result in different traits