Test On Evolution Flashcards
What is the gene pool?
Available alleles and genes in a population
What causes a mutation?
Changes in the structure of genes introduces new alleles
What is genetic drift?
Random events that can alter populations
Allele frequency may not represent the frequency in the original populations
What is gene flow?
Isolated populations with different alleles in the HW equilibrium
If a member crosses into another population it will add new alleles
What is selection when referring to genes?
Differences in the survival or success of a particular gene will change its frequency
What are methods of selection?
Preference of a particular allele will increase its frequency
What are Charles Darwin’s observations?
- animals give birth and pass on their traits
- there is variations of traits
- some variations will affect an individual’s chance to survive
- animals give birth to more offspring than the environment can support
- successful individuals have more offspring and pass on these traits
What is natural selection?
Selection for traits that are most successful in the current environment
What is sexual selection?
Selection caused by preferences of females for males traits
What is artificial selection?
-selection for a particular trait by humans, all domestic animals and plants have been
Behavioural selection example
Unibrow vs. Regular brow, the regular brow will be more accepted
What is an adaptation?
An inherited or collection of traits that increases an organisms chance at survival
-natural selection can only work on traits in the population
What is evolution?
The change in characteristics of populations during generations
What is evidence of evolution from Geology, Fossils, Chemistry, Astronomy, Biology
- similar rocks
- oldest fossils most primitive
- similarity between organisms
- earth is 4.7 billion years old
- embryos are similar
How does evolution occur?
Change in genetics over a long period of time
Where does genetic change come from?
Mutations, selection, gene flow, gene drift
Microevolution
Macro evolution
Minor changes in organisms
Major changes in organisms
Punctuated equilibrium
Gradualism
Evolution occurs during rapid jumps
Occurs slowly
How does a species form?
Population is divided and it adapts to its environment (can be geographic or reproduction)
What is phylogeny?
Evolutionary history of a species
What is evolutionary classification?
Grouping organisms based on evolutionary history (modern way to go it)
Convergent evolution:
Due to same pressures things start to look similar even though no common ancestor
It is only that the HW theory will stay in affect if:
Sufficient numbers of offspring No mutations Selection is prevented No inbreeding No selective breeding No assortative mating
What is the bottleneck effect?
Populations get wiped out due to disaster (different alleles)
How was earth formed?
Less dense compounds cooled and formed crust
Atmosphere composed of hostile gases
Water rained and rained
Rain sculpted earths crust and dissolved minerals
Sea is now full of minerals
Atmosphere charged with lightning
Thought heat, lightning and ultra violent radiation caused life
What did the Miller-Urey experiment show?
Spontaneous formation of macromolecules was possible with thought early atmosphere
Resulted in formation of organic compounds
How did the First cells develops a protective membrane?
Phospholipid molecules arranged into a spherical shape
How might have Eukaryotic cells produce internal membranes?
Folding outer shell to increase surface area
Evidence that supports mitochondria and chloroplasts were absorbed
Have own DNA
Independent cell division
Contain two membranes
What did the first fossils resemble
How would have they gotten energy
Blue-green algae (anaerobic)
Been chemo-autotrophic using H2S to create energy
How did the atmosphere change
Photosynthetic organisms release free oxygen
Oxygen forms ozone layer
Ozone reduces ultraviolet radiation reaching earth
What does continental drift affect?
Habitats
Changes weather patterns
Reroutes ocean currents
Fossils in different places
Consequences of mass extinction
Evolutionary lineages disappear
Reduction in diversity
Arising of adaptive radiations
What brings about adaptive radiation
A organisms movement into a variety of different environments or exploitation of food sources
What is a population?
Group of individuals that live in same area and are the same species
Community definitions
Assemblages of different populations that live in the same area
Ecosystem
All abiotic and biotic factors in an environment
Biosphere
Everything in the world
Who were James Hutton and Charles Lyell
Helped show earth was millions of years old
Hutton- rocks
Lyell-geological features could be built and torn down
What did Lamarck propose
Selective or disuse of organs could mean organisms acquired or lost traits and they would be passed down to offspring
Who was Malthus
Said if human population continued unchecked there would be insufficient living space and food
What is artificial selection
Nature provides selection and humans select variations found useful
What is the struggle for existence
Members of each species compete for food and other necessities
What is fitness
Ability of an individual to survive and reproduce in its environment
What is survival of the fittest
Individuals better suited for their environment survive and reproduce more successfully
What is natural selection
Like artificial selection but it contributes to an individuals fitness
Changes inherited characteristics of a population
What is decent with modification?
Each living species has descended with changes from other species
What is common decent?
Living and extinct derive from common ancestors
What are homologous structures
Different mature forms but descended from similar embryonic tissue
What are vestigial organs
Organs in animals that are reduced from homologous structures because they are no longer needed
What is a gene pool
Consists of all genes present in a population
What is relative frequency?
Number of times the allele occurs in the gene pool
What are two sources of genetic variation?
Mutations and genetic shuffling
What number of phenotypes control that trait?
Depends on how many genes control that trait
What is a single-gene trait?
A trait controlled by a single gene that has two allleles
What are polygenic traits?
Traits controlled by two or more genes
Why does natural selection never act directly on genes?
It is an entire organism that reproduces not a single gene
What can natural selection lead to?
Changes in allele frequencies and this to evolution
What are the three types of natural selection?
Directional selection
Stabilizing selection
Disruptive selection
What is directional selection?
When individuals at one end of the curve have a higher fitness than the others
What is stabilizing selection?
When the individuals have the high fitness at either end of the curve
Disruptive selection
Individuals at the upper and lower ends have hgiher
