lecture 3: plate tectonics

The position and orientation of continents have significant impacts on climate.
Continent configuration affects ocean circulation, which is crucial for climate patterns.
An understanding of continents' positions over evolutionary time can provide crucial insights into mammalian evolution and diversification.

Species: A group of organisms that can interbreed and produce fertile offspring.
Conservation Needs: Identifying areas and species requiring conservation efforts to preserve biodiversity.
Vicariance: The geographic isolation of populations of a once widespread species due to the development of a physical barrier within the species' ancestral range.
Dispersal: The one-way movement or spreading of organisms from their place of origin (natal site) to a new area.
Examples of geographical barriers: Islands, land bridges, etc.

Study of patterns of geographical distributions of living organisms (both extant and extinct) in relation to time and space.
It’s important to comprehend continental movements to understand the significance of vicariance and dispersal in current mammalian distributions.

Continental drift refers to the movement of large land masses across the Earth's surface over geological time as a result of plate tectonics.
It suggests land movement causes speciation and diversifies life forms over extensive time spans.
Plate Tectonics Theory: Explains the Earth's crust, including continents and ocean floors, is made up of a series of geological plates.
It drives continental drift, leading to changes in climate, species distribution, and ecological interactions.

Paleozoic Era: 540 – 250 million years ago (mya)
- Major events: Formation of supercontinent Pannotia and significant geological changes over time.
- Emergence of primitive vertebrates and land plants.
- First appearance of jawed fishes around 425 mya and the Age of Fishes in the Early Devonian period.
- Collision of continents during the late Permian led to the formation of the supercontinent Pangaea.
Mesozoic Era: 250 – 65 mya
- Known as the Age of Dinosaurs.
- Breakdown of Pangaea and diversification of species during this era, leading to significant evolutionary paths, notably of mammals.
Cenozoic Era: 65 mya – present
- Development of grasslands and grass-eating mammals.
- Climatic shifts and landscape changes including the uplift of mountain ranges like the Himalayas.

Major environmental changes have led to massive extinctions, including the Permo-Triassic Crisis, marking the greatest extinction event (96% marine species gone).
Recovery from such events took millions of years with significant drops in diversity impacting mammalian evolution.
Continuous mountain building and climatic shifts, particularly towards cooling in the Cenozoic, affecting the distributions and diversification patterns of mammals.