Natural Selection and Adaptation
What is the definition of an adaptation?
A trait that improves chances of survival and reproduction for a group of individuals in a population.
What is the best description of a fossil?
Remains of a once-living organism found in layers of rock, ice, or amber.
The forelimbs of a human, cat, whale, and bat have similar bone structures but perform different functions. What type of structures are these?
Homologous structures because the appendages have similar structures.
What type of selection occurs when natural selection favors one extreme variation of a trait?
Directional Selection.
What characteristic of populations is Elle observing when she notices that kangaroos of the same species have slightly different sizes and colors?
Variation
What specific information do fossils provide evidence for?
The history of life in the geologic past.
The tiny leg bones found in some whales are classified as what type of structure, suggesting they have lost their function over evolutionary time?
Vestigial structures.
The pike fish eats the larger guppies, making it harder for them to escape. What type of selection is this?
Directional Selection.
If a species of rodent lives in a moist forest that becomes drier and more desert-like, which adaptation would most likely improve its survival?
Being able to eat plants, like cacti, that survive in the changed environment.
What critical event must happen for a dinosaur bone to become a fossilized bone?
Minerals seeped into the dinosaur’s bones before they completely decomposed.
Emma discovers two modern-day species have very similar DNA. What type of evidence did she use to reach the conclusion that they are closely related?
Genetic evidence (or DNA).
In the hawk/mouse scenario, the hawk eats more white mice than dark mice. Which claim explains this change in the mouse population over time?
The hawks eat more white mice than dark mice because they can see the white mice more easily., so dark mice increase in population.
Why is the scenario of giraffes with longer necks surviving dry seasons and breeding more successfully considered an example of natural selection?
Because the environment (limited high leaves) selected the favorable trait (longer neck) for survival and reproduction.
In a diagram showing rock layers, which layer contains the most recently formed fossils?
the uppermost layer
If Species A and Species B share 97% DNA similarity, while Species A and Species C share 95% similarity, what can be concluded?
Species A has a closer evolutionary relationship with species B than it does with Species C.
If a predator preys primarily on medium sized cockroaches, leaving the large and small adults to reproduce, what type of selection is demonstrated?
Disruptive Selection.
What factor is least likely to cause a species to become extinct due to changes in the environment?
More genetic variation.
What is the correct order of the four steps of fossil formation: 3) Organism dies/covered by sediment, 4) Sediment builds up, 1) Minerals seep in/replace body with stone, 2) Organism completely decomposes?
3, 4, 1, 2.
Georgia compares the embryos of parrotfish and salamanders and finds they follow similar developmental pathways. What does this developmental evidence suggest?
That parrotfish and salamanders likely share a common ancestor.
If arctic fox do not have adaptations to survive rapidly melting ice, what long-term effect may occur to their species?
They may become extinct.