Evolution Flashcards
Define: Emigration
To leave a population
Define: Population Density
How many organisms there are in a given area.
Define: Immigration
To enter a population
Define: mortality rate
The rate at which organisms die
Define: natality rate
The rate at which organisms are being born
Define: Carrying capacity
Maximum number of organisms that can live in an area
Define: limiting factor
Something that affects the carrying capacity/slows population growth.
Describe: Logistic Growth Curve
Goes up then reaches a plateau
Describe: Exponential growth curve
Goes up steadily
Define: Density-dependant limiting factor
Accounts for how many organisms are in an area.
Ex. Disease
Define: Density-Independant limiting factor
Doesn’t account for how many organisms are in an area.
Ex. Tornado
P=?
Frequency of dominant allele
Q=?
Frequency of recessive allele
P^2=?
percentage of homozygous dominant individuals
Q^2=?
Percentage of homozygous recessive individuals
2PQ=?
Percentage of heterozygous individuals
What is the Hardy-Weinburg equation?
p^2+2pq+q^2=1
Who were Miller and Urey?
They recreated the early conditions of Earth in a lab experiment.
Define: primordial soup
When organic molecules accumulated in the oceans. (It was like soup)
What is the Endosymbiotic Theory?
Proposes that eukaryotic cells arose from living communities of prokaryotic organisms.
Who was Lynn Margulis?
Brought forth reasonable evidence to support the endosymbiotic theory in the 1960’s.
What was The Beagle?
The ship Darwin sailed on.
Darwin produced what theory?
The Theory of Evolution
Describe Darwin’s observations of the Galapagos finches
They were similar, but they all had different beaks on different islands. He figured that they had adapted to different food sources on the islands in order to survive. He figured they had all been part of one species.
Who was James Hutton?
He helped scientists realize that Earth was many millions of years old.
Who was Charles Lyell?
Published works that said the processes that changed Earth in the past are the same processes that operate in the present.
What did Darwin learn from Lyell?
He figured that if the Earth was constantly changing the same way, that organisms could too.
Describe Lamarck’s evolution hypothesis
He thought that by selective use or disuse of organs, organisms could lose or acquire traits. These traits could be passes on to offspring and would lead to a change in species overtime. Lamarck was wrong.
Why was Lamarck wrong?
He did not know how genetic worked and how traits were inherited. And that an organisms behavior does not affect it’s heritable traits.
Who was Thomas Malthus?
He reasoned that if the human population continued to grow, it would eventually be too big and there would be an insufficient food supply and space.
How did Malthus affect Darwin?
Darwin was able to assume that one species could overrun the world. This was central to Darwin’s idea of evolutionary change.
What was “On The Origin Of Species” and what was in it?
It was Darwin’s book about evolution. It contained his journal entries from his trip on The Beagle.
It proposed natural selection, and presented evidence that evolution has occurred and continues to occur now.
Who was Alfred Wallace?
He wrote a small essay to Darwin explaining that he had the same thoughts as Darwin. He successfully encouraged Darwin to publish his book.
Define: artificial selection
When plant and animal breeders breed the best. They choose who to mate with who to get the best possible outcome.
Define: fittest
An individual’s ability to survive and reproduce in it’s environment.
Define: adaptation
Any inherited characteristic that increases an organism’s chance of survival
Define: survival of the fittest
Those better suited to their environment survive and reproduce most successfully.
Define: natural selection
Same thing as survival of the fittest. Over time, natural selection results in changes in characteristics of a population. These changes increase a species fitness.
Define: descent with modification
Each living species has descended with changes over time.
What are the four main pieces of evidence of evolution?
- The fossil record
- Geographical distribution of living species
- Homologous body structures
- Similarities in embryology
Define: macroevolution
Refers to large scale evolutionary patters
What leads to genetic variation?
Each gene has two or more alleles, so the combination of alleles leads to genetic variation.
Define: Population
A group of individuals of the same species that intervreed
Define: gene pool
All the different alleles present in a population
Define: relative frequency
How many times an allele is present in a gene pool. When genetics is present, evolution can be defined as any change in relative frequency.
Define/Describe: Directional selection
Individuals at one end of the curve have a higher fitness than individuals at the middle of lower end. Curve shifts to the side.
Define/Describe: Stabilizing Selection
Individuals near the center have a higher fitness than individuals at either end of the curve. Curve becomes steeper.
Define/Describe: Disruptive Selection
Individuals at either end of the curve have a higher fitness. Curve becomes two humps. This can lead to a change in species.
Define: Genetic drift
Sometimes things happen by chance and a random change in allele frequency can occur due to small populations.
Define: Founder Effect
A small group of organisms carrying a different relative frequency of alleles may migrate.
Define: speciation
The production of a new species through separation of the gene pool
List the three isolation mechanisms
- Behavioral: different courtship rituals
- Geographic: separated by Earth
- Temporal/seasonal: reproducing at different times
