The Big Bang
Scientists estimate the Big Bang occurred about how many years ago?
What is 13.8 billion years ago?
This layer at the very top of the Earth, made of light rocks like basalts and granites, is the thin layer on which we live.
What is the crust?
Living organisms share four main characteristics: metabolism, homeostasis, reproduction, and this fourth trait that allows organisms to change across generations to suit their environment.
What is adaptation?
This is the process by which species change over time through small, gradual changes across generations.
What is evolution?
This term describes an event where very large numbers of plant and/or animal species are unable to adapt to changing conditions and disappear as a result.
What is a mass extinction event?
These two elements, still the most abundant in the universe today, made up most of the earliest atoms formed after the universe cooled enough for particles to stick together.
What are hydrogen and helium?
Name Earth's three layers in order from the outside in.
What is the core, the mantle, and the crust?
This ability of living organisms to regulate themselves, like humans sweating to control body temperature, is called this.
What is homeostasis?
These small, gradual changes help an organism survive and reproduce in a changing environment.
What are adaptations?
About 2–3 billion years ago, tiny bacteria began producing large amounts of this gas, poisoning and killing off most life on Earth in what became the first mass extinction event.
What is oxygen?
In the 1920s, this astronomer discovered that the universe was expanding while working with physicist Georges Lemaître to theorize the universe must have once been extremely small.
Who is Edwin Hubble?
This German meteorologist, working in the early 20th century, proposed that all the continents on Earth had once been united into a supercontinent he called Pangaea.
Who is Alfred Wegener?
According to the theory agreed upon by most scientists, life began in the ocean near these underwater features, where complex chemicals mixed with heat and energy from the mantle.
What are oceanic (hydrothermal) vents?
These imperfect copies made when genes replicate themselves are usually harmless, but can sometimes introduce helpful new traits.
What are mutations?
The nickname given to a mass extinction that occurred about 250 million years ago and killed up to 96% of marine animals and 3 out of 4 land species.
What is "The Great Dying?"
In the 1960s, astronomers Arno Penzias and Robert Wilson picked up strange signals on a radio antenna that turned out to be this leftover heat/radiation from the early universe.
What is cosmic microwave background radiation?
These separate, stacked layers of rock and sediment provided key evidence of a moving crust when similar ones were found in both West Africa and Brazil.
What is strata?
Scientists call the special set of conditions Earth has, including liquid water, a rocky surface, and just the right amount of energy, by this nickname.
What is Goldilocks Conditions?
This process occurs when individuals with beneficial mutations are more likely to survive and reproduce, causing those genes to become more common in a population over generations.
What is natural selection?
The most popular theory for the extinction that ended the dinosaurs' 165-million-year reign about 65 million years ago involves a meteor crashing into what modern-day country?
Where is Mexico?
This tongue-in-cheek "law" describes how scientific discoveries are often credited to the person who popularizes an idea rather than everyone who contributed to it (for example, how Darwin is remembered over A.R. Wallace).
What is Stigler's Law of Eponymy?
Wegener had heaps of evidence for continental movement but couldn't explain how it happened. It wasn't until this WWII-era technology, originally developed to track submarines, was used to map the ocean floor and reveal huge volcanic mountain chains, that scientists began to understand the mechanism.
What is sonar?
Earth's earliest organisms, which emerged about 4 billion years ago before the atmosphere even had oxygen, survived by living off minerals in the ocean instead of oxygen. What term describes organisms that live without oxygen?
What is anaerobic?
This scientist is most credited with discovering natural selection, although another naturalist, A.R. Wallace, arrived at similar ideas around the same time.
Who is Charles Darwin?
Scientists estimate that the current extinction rate, largely driven by human activity like deforestation, fossil fuel use, and habitat destruction, is how many times higher than the natural extinction rate?
What is 100 times?