Cladograms
Species E
How old is the Earth?
4.6 Billion years old
What might be the reason that birds would have different types of beaks?
They eat different types of food.
What is directional selection?
Individuals at one end of the curve have higher fitness than those in the middle or at the other end.
What are polygenetic traits? Provide three examples.
Traits that are controlled by 2 or more genes.
Eye color, hair color, and skin color.
Refer to the shown cladogram -What species # is the shared common ancestor between all species on the cladogram?
Species #6
What species are humans most closely related to?
What about on the image shown? Who are humans most closely related to on this image?
Chimpanzee
Pig
What is evolution?
The process of change over time.
What is stabilizing selection?
Individuals at the graph curve's center have higher fitness than those at either end.
Which organism on earth evolved first?
Bacteria
Refer to the shown cladogram - How many traits do we know that species E and species G share?
2
What are vestigial structures? Provide an example.
Structures that have lost most or all of their original function. Ex - Hip bones in dolphins, and appendix in humans.
Describe one complete example / scenario of natural selection.
Ex - A population of rabbits live in a snowy area. Some of the rabbits are white and some are gray. The gray rabbits cannot blend into the background, so they are more easily eaten by wolves. The white rabbits can use camouflage to help escape from predators or avoid detection altogether. The white rabbits have an advantage and are better suited to survive in this environment.
What is reproductive isolation? Create an example.
Occurs when a population splits into two groups and the two populations can no longer interbreed.
Ex - Any two groups of similar animals that cannot physically reproduce with each other.
What is genetic drift? When does genetic drift have the largest effect?
A random change in allele frequencies. In a small population.
Describe "Descent with Modification". What does it mean?
Living species are descended, with changes / modifications, from shared common ancestors.
What are homologous structures? Provide an example.
Structures that have shared physical structure but a different function. Ex - The front limbs of a chicken and the front limbs of a frog.
What is a mimicry adaptation? Describe one example of one.
Adaptation - Any inherited characteristic that improves an organism's ability to survive and reproduce in its environment.
Mimicry - An organism copies or mimics a more dangerous organism.
Ex - Viceroy mimics the monarch butterfly to avoid being eaten as the monarch is poisonous.
What is geographic isolation? Create an example.
Two populations are separated by by geographic barriers such as rivers, mountains, or bodies of water.
Ex - Finches on the Galapagos islands - separated by islands / water.
What type of environment has the greatest chance for genetic change?
- What size?
- More or less mutations?
- More or less immigration?
Small size, many mutations, and more immigration.
Refer to the cladogram shown, what two characteristics do crabs and barnacles share that limpets do not?
Molted external skeleton and segmentation.
What are analogous structures? Provide an example.
Body parts that have a different structure but a shared function. Ex - Bee wing and a bird wing.
What is convergent evolution? Provide an example.
Produces similar structures or characteristics in distantly related organisms because of similar environments & life style.
Ex - Anteaters, armadillos, pangolins, and aardvark.
Why does antibiotic resistance occur?
Variation in bacteria means that some might possess the ability to survive, and if they do, they will then be able to reproduce and create more bacteria that are able to survive the antibiotics.
What is a mutation? Why might a mutation be passed down and spread throughout a population?
A change in genetic information / code. If an individual with that mutation is successful at reproducing, then the mutation will be passed down. If the mutation is beneficial, it is likely that it will spread throughout the population, but not guaranteed. A mutation that improves one’s chances to reproduce, such as a desirable attribute, would also lead to it being passed through a population.