Evolution Test Flashcards
What is the official definition of evolution?
Descent with modification
What does evolution include?
It includes large scale (species level) and small scale (allelic level) evolution.
What is a WRONG definition of evolution and why?
“Change over time” because….
- Terrestrial vertebrates evolved from ____
- Whales evolved from ____
- Birds descended from ____
- Fish
- Terrestrial mammals
- Theropod (walk on 2 feet) dinosaurs
EXPLAIN HOW TO READ AN EVOLUTIONARY TREE.
Good job!
+5 bonus points
WHAT ARE THE:
1. Notochord
2. Dorsal hollow nerve cord
3. Gill slits
4. Postanal tail
These are all developmental/embryonic homologies.
1. It is a half-developed spine, is a stiff rod of cartilage
2. It is a half-developed spinal chord.
3. This is obvious.
4. This is also obvious.
What is a vestigial structure? Give an example
They are structures that are left over from past ancestors but aren’t as functional now.
What is THE OTHER definition of evolution? Give an example of this definition.
The change of allele frequency in a population
NOTE - this assumes you’re only talking about one species.
What is important to note about evolution?
It can only happen between multiple generations and can’t happen with a single individual.
What are the Factors that must be present for evolution to occur? Explain each one.
- Genetic variation
- Competition for survival between individuals
- Individuals with beneficial adaptations
- Natural selection, which changes the frequency of alleles (EVOLUTION!)
What are the mechanisms of evolution? Explain each one.
- Natural selection
- Genetic drift (explain the Bottleneck Effect and the Founder Effect.)
- Sexual selection (traits better suited for mating are passed down)
- Mutations
- Gene flow, migration & emigration
What do beneficial adaptations do?
They increase the fitness of the population
What is artificial selection/selective breeding? Give an example.
It’s when humans purposefully breed individuals with desired traits so that the offspring will have them. It’s a mechanism of evoltuion.
What is mimicry?
Explain Batesian mimicry vs. Mullerian mimicry
Mimicry is when a species evolves to look more like another, giving the species an advantage
What is stabilizing selection? Draw it. Explain how you can remember it. Give an example.
It’s when the intermediate phenotype is favored. It can reduce genetic variation. It happens when environmental conditions are stable and compeititon is low.
What is direction selection? Draw it on paper, say how you can remember it, and give an example.
It’s when one phenotypic extreme is selected, and the distribution shifts in one direction.
It’s a response to a sudden or gradual environmental change.
It will typically be followed by stabilizing selection once the optimal range of traits is reached.
What is disruptive selection? Draw it, say how you can remember it, and give an example.
It’s when both phenotypic extremes are favored, resulting in bimodal spread (2 separate hills)
It’s the result of fluctuating environmental conditions (ALTHOUGH THIS IS WRONG.)
THIS TYPE OF SELECTION COULD RESULT IN SPECIATION.
What is speciation?
Explain geographic and reproductive isolation.
Speciation is the rise of a new species from an old one.
Geographic isolation happens when one population gets geographically separated from another, and they evolve separately. This could lead to the formation of new species (to the point when they can’t breed and make compatible offspring)
Reproductive isolation is when individuals aren’t able to reproduce for certain reasons, like different mating calls, or mate in different seasons. Eventually, this could result in 2 separate species forming.
What is a species?
A species is a group of animals that could reproduce to form fertile offpspring.
