This type of rock, formed from compacted layers of sand and mud, is where we almost always find fossils.
What is sedimentary rock?
By studying meteorites, scientists estimate that the Earth is roughly this many billion years old.
What is 4.6 billion years?
This process in the mantle, where hot, less dense rock rises and cooler, denser rock sinks, is the engine that drives plate movement.
What is thermal convection?
When water seeps into a rock crack and freezes, it expands and breaks the rock apart. This is a form of this type of weathering.
What is mechanical (or physical) weathering?
A cat's front leg and a bat's wing have the same bones but different uses. These are called this type of structure.
What are homologous structures?
The fossil record of this massive modern marine mammal shows it slowly evolved from a four-legged land animal.
What is the whale?
During the Hadean eon, right after Earth formed, the surface was entirely covered in this extremely hot substance.
What is magma (or lava/molten rock)?
The Great Rift Valley in Africa is an example of this type of boundary, where tectonic plates are pulling apart.
What is a divergent boundary?
Rainwater naturally mixing with carbon dioxide creates a weak acid that dissolves limestone to form caves. This is an example of this type of weathering.
What is chemical weathering?
Homologous structures, like the arm bones in humans and manatees, provide strong evidence that the two different species share this.
What is a common ancestor?
Finding identical fossils of the freshwater Mesosaurus in both South America and Africa proves this scientific theory.
What is continental drift (or Plate Tectonics)?
According to the Giant Impact Hypothesis, a Mars-sized planet crashed into early Earth, resulting in the creation of this object.
What is the Moon?
When a heavy oceanic plate collides with a lighter continental plate, it gets pushed underneath and melts in a process called this.
What is subduction?
Water molecules are polar, meaning they like to stick to other surfaces. This property, which allows water to travel up plant roots, is called this.
What is adhesion?
A shark's fin and a dolphin's fin do the exact same job but have completely different internal bones. These are called this type of structure.
What are analogous structures?
If you find fossils of ancient, warm-water coral reefs in the snowy mountains of Canada, it tells you this about the ancient environment.
What is it used to be a warm, shallow sea?
During the Late Heavy Bombardment, meteorites are thought to have delivered organic compounds and this essential liquid to Earth.
What is water?
The Himalayas are actively growing taller every year because two continental plates are doing this.
What is colliding (or forming a convergent boundary)?
When large mountain glaciers melt, they expose dark rock underneath. The dark rock does this to solar heat, which speeds up global warming.
What is absorbs it?
While homologous structures point to common ancestry, analogous structures point to organisms independently adapting to the same type of this.
What is environment (or lifestyle)?
Because we have fossils of horse ancestors with multiple toes, the fossil record provides evidence that the physical forms of organisms do this over time.
What is change (or evolve)?
We cannot find Earth rocks that are 4.6 billion years old because the original crust was destroyed by this process.
What is intense heat (or crustal recycling/melting)?
Although they can course at others, these plate Bouondaries are the most likely to have earthquakes.
What are convergent plate boundaries
While glaciers bulldoze wide "U-shaped" valleys, fast-flowing mountain rivers carve out valleys shaped like this letter.
What is a "V"?
In evolutionary biology, the greater the number of anatomical similarities two organisms share, the more recent this historical biological figure is.
What is their common ancestor?