Natural Selection
How are natural selection and fitness connected?
Natural selection is when an organism is selected over others for having a beneficial trait. This means they are more fit for their environment.
What is speciation; how does it happen?
The devolvement of a new species. Isolation MUST occur. This causes a shift in the gene pool to occur.
What fields of science can support evolution with evidence? (Name 3)
Paleontology, Biochemistry, Biogeography, Morphology, Embryology
What is a phylogenetic tree?
It is something used to predict evolutionary relationships among organisms
(Evidence used from Morphology and Paleontology)
The wings of flightless birds, like the ostrich, are an example of ____________________.
vestigial structures
What is the difference between gene flow and genetic drift?
Gene flow: movement of genes in and out of a population
Genetic drift: random change in frequency of alleles in a population over time
Land animals came from whales. This was a slow and steady process. This is an example of what pattern of evolution?
Gradualism
The more or less homologous structures, the more closely related the species is.
More
What is the correct order of hierarchical evolution beginning with domain?
Domain - Kingdom - Phylum - Class - Order - Family - Genus - Species
A physical trait that increases an organism's ability to survive in its environment is an example of ___________.
What is meant by the phrase "Individuals don't evolve, populations do"?
Individuals can have mutations that cause a better fitness level to exist. Overtime, you will see a shift in the gene pool as the population evolves.
Bumblebees and flowers forming a mutualistic relationship and changing together is an example of...
Coevolution
What is a vestigial structure and why does it exist? Provide an example in humans and one other organism.
A structure that currently has no function/use. It served a purpose in a previous ancestor (a result of divergent evolution).
Humans: wisdom teeth
Whales: hip bones
When looking at a phylogenetic tree:
Typically: is the organism right after another more closely related or the one right before?
Typically after. They have a more recent common ancestor compared to the organism that diverged first.
Principle of natural selection that explains how beneficial traits should become more common over time, causing a change in allelic frequencies is ___________________.
descent with modification
What are the four principles of natural selection and give an example of them.
1. Overproduction of offspring: competition for resources
2. Variation: types of traits that are seen in the population (thick, medium, and thin fur coats in polar bears)
3. Adaptation: the more beneficial trait (thinner coats due to the warming temps)
4. Descent with modification: overtime, the shift in alleles the population will have (thinner coats due to warming temps)
Convergent vs divergent. What's the diff?
Convergent: not a common ancestor BUT similar function due to environment.
Divergent: a common ancestor that had speciation occur.
What has to occur for speciation to happen and why?
Isolation of some sort. This causes the genes to be separated and to shift enough that the gene pools no longer align. Fertile and viable offspring between the two would not occur. That's how you know a new species has emerged.
What is the endosymbiotic theory?
Coevolution of two prokaryotes led to speciation and the 1st eukaryotes. (One prokaryote grew inside of another and the gene pool shifted enough that eukaryotes were created.)
Organisms with traits that make them better adapted to their environment will live longer and reproduce more is an example of _______________.
natural selection
Can genetic equilibrium be achieved?
NO! You will always have shifts in the gene pool due to migration and due to mutations.
(Natural selection can't happen and only random mating)
How could an organism evolve by punctuated equilibrium and gradualism?
Mutation caused the trait to appear all the sudden. Over time, that trait led to a higher fitness level and was seen more often in the population.
Homologous and analogous.
- What are they?
- How are they derived?
- What is an example of each?
Homologous: same structure (layout) and a different function (job). Comes from divergent evolution. Human arms and bat wings.
Analogous: different structure (layout) and the same function (job). Comes from convergent evolution. Insect wings and bird wings.
Phylogenetic trees are assembled based on what types of evidence/findings?
Shared morphology
Shared genes
Shared behaviors
Similar body structures, such as fins, due to organisms living in the same environment, not same ancestry is an example of ________________.
*What kind of evolution does this derive from?
*convergent