15.1: Fossils & the Fossil Record
15.2: Theory of Evolution
15.3: Evidence for Evolution
15.4: Natural vs. Artificial Selection
Random ?s.
100
Remains or traces of organisms from the distant past are called __.
What are fossils?
100
A change in a species over many generations is called __.
What is evolution?
100
Name one type of evidence scientists use to support evolution.
What are:
Fossils, homologous structures (anatomical similarities), vestigial structures, & similar embryos
100
This decides which traits are passed on in natural selection.
What is the environment?
100
What do we call it when organisms compete for limited resources?
Competition.
200
This is the name for the timeline of life based on fossil evidence.
What is the fossil record?
200
This scientist is credited with first developing the theory of evolution by natural selection.
Who is Charles Darwin?
200
Which animals are carnivorous?
What are the wolf, leopard, & domestic cat?
200
This selects traits in artificial selection.
Who are humans?
200
Name one environmental pressure that causes natural selection.
Predation, climate, disease, food availability, competition.
300
This law states that older layers are found below younger layers in undisturbed rock.
What is the Law of Superposition?
300
This group of 16 volcanic islands near the equator is where Darwin spent months exploring, collecting specimens, & writing observations in his journal.
What are the Galapagos Islands.
300
A __ is a body part that has lost its original function (like a human tailbone).
What is a vestigial structure?
300
List and describe two environmental pressures.
- Climate: Factors like temperature, the amount of precipitation, light availability, or seasonal change play a big role when it comes to which organisms are best fit for the environment. Ex: In hot environments, animals with thinner fur or larger ears (like desert foxes) may release heat more easily and survive longer.
- Food availability: Habitats cannot produce enough food for all of the organisms that live there. This leads to natural selection favoring individuals with traits that allow them to easily get these resources. Ex: Birds with slightly longer beaks may be able to reach deeper into flowers to get nectar, giving them an advantage.
Disease: Diseases can quickly spread from one organism to another unless individuals have some resistance to infection. Ex: A population of frogs might include individuals with slight genetic resistance to a fungus. If a disease spreads, only those with the resistant trait may survive and reproduce.
Competition: When resources (not just food) are limited, organisms must compete for them. The strongest competitors live long enough to reproduce & transfer their DNA to their offspring. This is often summed up as "survival of the fittest". Plants that grow taller than others may get more sunlight and outcompete their neighbors.
300
True or False: Artificial selection (unlike natural selection) does not take many generations.
False
400
Which fossil is oldest? Which is youngest?
Oldest fossil = Trilobite
Youngest fossil = Fern
400
A ___ is a trait that helps an organism survive and reproduce.
What is an adaptation?
400
Why do whales have hip bones even though they don’t walk?
It’s evidence they evolved from land-walking ancestors.
400
What do natural and artificial selection have in common?
Both cause traits to become more common in a population over generations.
Both are possible because of there is some genetic variation within a species.
Genetic variations are inherited from parent generations.
400
Give an example of a vestigial structure.
Human tailbone, wisdom teeth, or goosebumps.
Whale's pelvic bones.
Penguins using their wings to swim, not fly.
Moles (who live underground) have eyes, but they are covered in skin.
500
Explain the difference between radiometric & relative dating.
Radiometric dating uses radioactive decay to get a more precise age of a fossil. Relative dating compares the layers that a fossil is found in. Fossils found lower down are older than ones found closer to Earth's surface.
500
Darwin's observations suggested that...
animals are well-suited for their specific environments and roles within those environments.
500
Scientists can use the fossil record to show evidence of evolution. Name three ways the record supports the theory.
1. Changes over time - fossils found in older rock layers look very different from those in newer layers (showing life has changed over time).
2. Transitional fossils - some fossils have features of two different groups of animals showing how an animal could slowly evolve over time.
3. Extinct species - many fossils are from species that no longer exist. This shows that not all life survives when the environment changes, species must change, too.
4. Similar body structures - similar bone patterns are a clue that some animals may have shared a common ancestor long ago.
500
Why might a trait chosen by humans in artificial selection not help in nature?
It may not help with survival or reproduction in the wild.
For example, over time, farmers have bred chickens to have larger and larger muscles (more meat to sell). An unintended result is that these chickens cannot easily walk around their environment.
500
Name the three types of animals that cK12 mentioned Darwin studying. Explain their variations.
What are:
Iguanas - Some are adapted for land (hanging out eating cacti) while others are marine iguanas (swimming & diving for seaweed).
Giant tortoises - Tortoises living on islands where plants were taller had longer necks to reach their food. Tortoises that lived where low-growing plants were had shorter necks.
Finches - Each island had their own species of finch based on what they ate.