Note
Studied by 596 people
Unit 8 Study Guide
Evidence for Evolution
What is the difference between relative dating and absolute dating of fossils? Relative is an estimate and absolute is exact.
What is a transition species? The intermediate states between an ancestral species and its descendants
Describe the three different types of structures pictured below:
What do the similarities in the embryos shown below suggest about the evolutionary history of these species? That animals evolved from a common ancestor
What is artificial selection? What is the difference between natural selection and artificial selection? Artificial selection is where humans choose what traits they want in a population and the difference between the two is that natural selection is picked by environmental factors
Below is a table showing the comparison of different animals to humans based on their amino acid sequences of a protein called cytochrome. What does high similarity in amino acids mean in terms of relatedness, and what does high difference mean in terms of relatedness? High similarity means they’re genetically similar, high difference means they are genetically different.
How can biogeography be used to explain the distribution of closely related species across the world? It can be used to explain how and why species live where they are
Microevolution (including Natural Selection)
What is the definition of microevolution/evolution? Change in the allele frequencies of a population over time
What are the mechanisms or causes of evolution? Natural selection, migration/gene flow, genetic drift, mutation
Provide a brief description of each type of mechanism of microevolution.
What are the four ideas that are the basis of Darwin’s theory of evolution by natural selection? Use the images below to help you. There is genetic variation in a population, organisms over-reproduce, there is competition for limited resources, competition results in differential survival and reproduction.
For each pattern of natural selection, identify the type of selection shown in the graph and describe each type of selection:
Explain why each of these statements about natural selection or evolution is FALSE:
You and your friend are talking about biology, specifically about how whales evolved and will continue to evolve. They say that whales will eventually get gills because they live in the water. Using your knowledge of natural selection, explain why that is unlikely to happen. It's unlikely because whales already successfully breathe air through their lungs so why mess that up.
What is the definition of an adaptation? The process where an organism is better adapted to their environment
What does “fitness” mean, in the biological sense? Successfully reproducing and surviving
What type of population is most affected by genetic drift: small populations or large populations? Small populations
What is the founder effect? How does it affect genetic variation in a population? A new population gets established from a small number of individuals from a larger population, leads to a new population with a unique genetic makeup
What is the bottleneck effect? How does it affect genetic variation in a population? A sharp reduction in the size of a population due to environmental events
Macroevolution
What does extinction mean? When a species is eliminated
What are the two different types of extinction? background/normal extinction and mass extinction/extinction of species over a short period of time
What does speciation mean? What needs to happen for speciation to occur? The process of forming a new species. Members of a population must be isolated, then over time each population changes, and then there are enough differences and the two populations can’t mate anymore
Describe the different types of reproductive isolation listed below:
Geographic isolation - species are physically separated
Behavioral isolation - courtship rituals are different
Temporal isolation - two organisms mate at different times in a year
What is the difference between punctuated equilibrium and gradualism? punctuated equilibrium is a pattern of stable periods interrupted by brief periods of more rapid change and gradualism is a slow steady change in a particular line of descent.
What is the difference between divergent evolution and convergent evolution? In divergent evolution, species branch of a common ancestor, in convergent evolution species evolve similar traits separately
What is coevolution? Species strongly affecting each other’s evolution