Unit 3.2 Origins of biodiversity Flashcards
Theory of Evolution
Evolution explains how species gradually change from ancestral forms into new ones through genetic changes over generations, primarily driven by natural selection
Natural selection
mechanism of evolution where individuals with traits better adapted to their environment have higher survival and reproductive rates, passing those traits to offspring.
Specification
The process of forming new species when populations become reproductively isolated and evolve differently due to natural selection and genetic drift.
Role of Isolation in Speciation
Geographic and reproductive isolation are crucial for speciation, preventing gene flow between populations and allowing for independent evolutionary paths.
Tectonic Plates and Biodiversity
The movement of tectonic plates can create barriers (mountains, oceans) leading to gene pool isolation and speciation, contributing to Earth’s biodiversity.
Impact of Continental Drift
Continental drift can lead to species isolation, promoting unique species development as seen in Australia’s marsupials and Madagascar’s lemurs.
Mass Extinctions
Earth’s history has seen five mass extinctions caused by catastrophic events, leading to significant biodiversity loss but also paving the way for new species through adaptive radiation.
The Sixth Mass Extinction
Currently underway, attributed to human activities, such as habitat destruction, pollution, and climate change, occurring at an unprecedented rate.
Human impact on evolution
Humans have significantly influenced species evolution and extinction rates through activities like agriculture, urbanization, and environmental degradation.
Conservation Importance
Understanding the origins of biodiversity and the impact of mass extinctions emphasizes the need for conservation efforts to protect endangered species and habitats.
The mid Atlantic Ridge
Location and Significance: The Mid-Atlantic Ridge is a boundary between the Eurasian plate and the North American plate, stretching along the Atlantic Ocean floor.
Mountain Range: It’s part of the world’s longest mountain range.
Volcanic Activity: Volcanic eruptions along the ridge can create new islands.
Formation of Islands: Surtsey and Iceland were formed from magma rising through rifts along the ridge.
New Habitats: These new islands offer fresh habitats for species colonization.
Biodiversity Hotspots: New islands can become hotspots of biodiversity as new species establish themselves.
Geological Activity: The ridge is an active site of geological processes, including seafloor spreading.
Ecological Significance: New ecosystems develop on these islands, providing unique study opportunities for ecologists.
Conservation Opportunities: Untouched by human activity, these new islands offer a pristine environment for conservation.
Research Value: They serve as natural laboratories for studying evolution, colonization, and ecosystem development
