Evolution Flashcards
Scientists hypothesize that modern cheetahs have experienced two genetic bottlenecks. Scientists estimate the first occurred during the last ice age and the second occurred during a time of rapid agricultural growth in cheetah habitats. The graph shows the population size before and after the first bottleneck event occurred and just before the second bottleneck event.
The bottleneck event caused genetic diversity to ________.
decrease
B.E.1
Scientists hypothesize that modern cheetahs have experienced two genetic bottlenecks. Scientists estimate the first occurred during the last ice age and the second occurred during a time of rapid agricultural growth in cheetah habitats. The graph shows the population size before and after the first bottleneck event occurred and just before the second bottleneck event.
Explain how bottleneck event 2 may have affected the cheetahs’ ability to adapt to variable environmental conditions
- There is a decrease in the minimum viable population size
- There is a decrease in the ability to adapt to environmental changes
- There is a greater chance of a harmful recessive gene impacting the population
B.E.1
What is a cladogram used for in the study of organisms?
To show the relationships among groups of organisms.
Rank the following animals from most closely related (1) to least closely related (4) to the roaches: Bristletails, Mayflies, Moths, Velvet Worms.
- Moths
- Mayflies
- Bristletails
- Velvet Worms
How many common ancestors do roaches and the most closely related segmented animal share?
4
Which traits are possessed by beetles?
- Wings
- Exoskeletons
- Wing sheaths
- Folding wings
Which two organisms are most closely related?
Moths and Beetles
What traits are displayed by different groups of plants?
- Cones
- Cuticles
- Flowers
- Needles
- Seeds
- Stomata
Which two groups of plants share the most recent common ancestor?
- Gingko
- Wheat
What traits are shared among the most recent common ancestor identified in Part A and its descendant groups?
- Cuticles
- Seeds
- Stomata
Which statement explains the relationships among gingko, spruce, and wheat?
Spruce share an ancestor with a group that contains gingko and wheat
The map shows the geographic distribution of salamander subpopulations that descended from the common ancestor E. e. oregonensis. Over millions of years, the salamanders moved south from what is now Oregon and northern California into areas to the east and west of California’s Central Valley.
The salamanders were initially separated by a large lake, and later by the unsuitable habitat of the Central Valley itself. Because of this geographic barrier, gene flow among some of these subpopulations is extremely limited, and in some cases has led to reproductive isolation.
What geographic barrier initially separated salamander subpopulations?
A large lake
What is the result of limited gene flow among salamander subpopulations?
Reproductive isolation
Which two salamander subpopulations can experience gene flow?
- L and N
- M and O
- O and P
B.E.1
Which two salamander subpopulations would be least likely to reproduce successfully if brought together?
Salamanders P and N
B.E.1
Warblers are small insect-eating birds common to North America. Several closely related species of warblers evolved approximately two million years ago during the period between the advance and retreat of large glaciers.
Which statement explains how this glacial activity led to the formation of these species?
Glacial ice separated and isolated warbler sub-populations.
B.E.2
What is the significance of the common ancestor’s DNA strand in genetic studies?
It helps determine the relatedness of different species by comparing sequences.
B.E.2
What is the best indicator of an organism’s evolutionary fitness?
Offspring it produces that survive to reproductive age.
B.E.1
Scientists have recently reclassified two populations of organisms that were originally classified as the same species. They are now classified as two unique species because of genetic differences that have been observed between the two populations. One of these populations lives on the mainland and the other lives on a nearby island. Both populations live in forest habitats and have similar diets.
Which factor is most likely responsible for genetic differences between two populations of organisms?
The geographic isolation of the island population prevented gene flow between the two populations.
B.E.1
Researchers studying hummingbirds in the Andes Mountains of Ecuador made several observations:
- There are many species of hummingbirds.
- The species are not separated by any physical barriers.
- Unique hummingbird species are found at different elevations in the Andes.
Which hypothesis is based on these observations?
Conditions at each elevation favor different hummingbird traits.
B.E.1
The sand goby is a small fish found in Europe’s Baltic Sea. During mate selection, females overwhelmingly choose males with large body sizes. In some parts of the Baltic, algae overgrowths are causing the water to become increasingly cloudy. In the cloudy water, females have trouble identifying the larger males.
What could happen if female sand gobies struggle to identify large males due to murky water?
There will be a change in how often genes for large size occur in the population.
B.E.1
Rock pocket mice live in the American southwest. Millions of years ago, the region’s rocks and sand were light-colored. About 1.7 million years ago, volcanic eruptions made the rocks and sand dark-colored.
Determine phenotype frequency data that correspond to the effect of the volcanic eruptions.
What was the phenotype frequency for rock pocket mice 2 million years ago?
Dark color is less than 50% and light color is greater than 50%.
B.E.1
Scientists and doctors have observed that many species of bacteria are no longer susceptible to antibiotics that were once effective.
Which statement explains why some bacteria species are no longer susceptible to certain antibiotics?
The bacteria that survived the antibiotics passed that resistance to future generations.
B.E.1
What explains the dietary specialization of lizard species P?
Lizard P has more genetic variability than lizards M, N, and O.
Genetic variability can lead to niche specialization in diets.
