Biol 100 Midterm #1
Transitional Forms
Transitional Forms - Fossils or organisms that show the intermediate states between an ancestral form and that of its descendants
Observational studies
researcher has no control of variables in study
Migration
seasonal movement of animals from one region to another
Founder Effect
when a very small number of animals leave the larger group to start their own population
Directional Selection
Favors one phenotype over another
Out of Africa hypothesis
Out of Africa hypothesis - is, in paleoanthropology, the dominant model of the geographic origin and early migration of anatomically modern humans (Homo sapiens), which proposes a single area of origin for modern humans
In order to eliminate subject bias, a __ is given to the control group subjects. a placebo b control c variable d blindfold
Placebo
Homology (Genetic, structural, behavioral, and developmental)
anatomical similarities between organisms, shared developmental pathways, DNA similarities, vestigial traits in modern species
A vestigial trait is _? a a newly evolved trait b a trait that lost its original function c an adaptive trait d all of the above
b
Assortative Mating
is a mating pattern and a form of sexual selection in which individuals with similar phenotypes mate with one another more frequently
Disruptive Selection -
favors the extremes
Macroevolution
happens on a scale that transcends the boundaries of a single species(large)
Experimental studies
have control over the variables and observe results
Non-Random Mating
inbred, mate with relatives
Experimental bias
is a process where the scientists performing the research influence the results, in order to portray a certain outcome.
Geological Time Scale
is a system of chronological dating that relates geological strata (stratigraphy) to time
Natural selection
is occurring when genetic variation results in unequal reproductive success among individuals in a particular environment
Evolutionary Fitness
is the quantitative representation of natural and sexual selection
Dependent or response variable
is what you measure in the experiment and what is affected during the experiment.
Inheritance of acquired characteristics
physiological changes acquired over the life of an organism may be transmitted to offspring
Independent or explanatory variable
- a variable that stands alone and isn't changed by the other variables you are trying to measure.
Double blind study
- is one in which neither the participants nor the experimenters know who is receiving a particular treatment
Mass extinction
5 extinctions, define major geological time periods
In a study to investigate the health effects of caffeine, the experimental group is given regular coffee. What is the best control group to include in this study? a A group given nothing. b A group given iced coffee. c A group given flavored coffee. d A group given decaffeinated coffee.
A group given decaffeinated coffee
Theory
A hypothesis or hypotheses that have not been disproved despite being tested many times by experiment or observation
Alleles
A particular version of a given gene
Microevolution
Allelic frequencies fluctuate inside the population(small)
A scientific theory is a an absolute truth that can never be changed b an educated guess c an explanation that has been well tested and is supported by all available data d an explanation that is supported by most, but not all, data
An explanation that has been well tested and is supported by all available data
Biological species concept
Biological species concept - It states that species are defined by who they can successfully mate with
Convergent evolution
Character similarities due to anything other than descent from a common ancestor, similar selective pressures from similar environments
Denisovan
Denisovan - People from Oceania share 4-6% nDNA with Denisovans following interbreeding in SE Asia
One of Darwin's two great ideas was evolution by natural selection, what his other great idea? a Traits evolved during an individual's lifetime b Descent from a common ancestor c Species were individually created d Organisms were full of imperfections
Descent from a common ancestor
Mutation
Errors in DNA replication
An adaptive trait decreases evolutionary fitness. a True b False
False
Genealogical Species concept
Genealogical Species concept - the smallest set of organisms that share an ancestor & can be distinguished from other such sets, populations could be separate species
Which force would be strongest initially for a population started by founder effect? Why? a Genetic drift; the founder effect creates a small population where genetic drift is strongest b Natural selection; the founder effect creates a large population that is under weak selection c Reproductive isolation; a founder population is reproductively isolated d Directional selection; a population by founder effect will always undergo directional selection
Genetic drift; the founder effect creates a small population where genetic drift is strongest
What is the ultimate source of all heritable variation? a Natural selection b Genetic drift c Sexual reproduction d Genetic mutation
Genetic mutation
Human evolution
Human evolution - Molecular estimates indicate Hominini-chimp lineage split ≈ 7.5 mya
Lamarkian evolution
If an organism changes during life in order to adapt to its environment, those changes are passed on to its offspring.
The experimental and control groups should be as similar as possible, differing only in the one thing you are trying to test. This one factor that you manipulate is called the _. a correlation b dependent variable c independent variable d placebo
Independent variable
Selection happens to ; evolution happens to . a individuals; individuals b individuals; populations c populations; individuals d populations; populations
Individuals; populations
Leaky replacement or admixture hypothesis
Leaky replacement or admixture hypothesis - Homo sapiens won and replaced the neanderthals
Morpho species concept
Morpho species concept - Species are groups of individuals that are morphologically similar & clearly distinguishable from individuals of other groups
Gene Flow
Movement of alleles between populations
Multiregional hypothesis
Multiregional hypothesis - homo erectus left Africa 2 mya to become homo sapiens in different parts of the world
Neanderthal
Neanderthal - Asians & Europeans share 1-4% nuclear DNA with Neanderthals following
Scientific Method
Observation Hypothesis (falsifiable) Prediction Test Conclusion
Speciation
One species splits into two or more species.
What is the source of genetic variation in peppered moths? a The environment (coal pollution) b Random mutation
Random mutation
Which of the following is a scientific hypothesis? a Why do I catch colds so often? b Regular exercise may reduce our risk of catching colds. c Our risk of catching colds may be influenced by our moral character. d I get a cold every christmas.
Regular exercise may reduce our risk of catching colds.
Reproductive isolation Prezygotic Post zygotic Mechanical Temporal Behavioral Ecological
Reproductive isolation - Reproductive differences evolve that will prevent successful mating even if the barriers disappear Prezygotic - eggs and sperm of different species are unable to fuse. Post zygotic - the hybrid offspring is viable but cannot reproduce Mechanical - sexual organs are incompatible. Temporal - differences in timing of reproduction Behavioral - differences in mating behavior may interfere with reproduction Ecological - populations occupy same territory but live in different habitats
Sample size
Sample size - determination is the act of choosing the number of observations or replicates to include in a statistical sample
Female mate choice Male-Male competition
Sexual selection - intelligence is sexy Female mate choice - intersexual selection Male-male competition - intrasexual selectio
Which of the following is a testable (ie- there is a possible way to disprove it) hypothesis? a Your luck is influenced by your actions in a previous life. b Embryonic stem cell research is unethical. c The Dinosaur T. Rex used a distinct call to attract mates. d Singing can decrease your cholesterol levels.
Singing can decrease your cholesterol levels
Genetic Drift
Some alleles can increase in frequency by chance, even though they're not adaptive in any way
Species
Species - is the smallest evolutionarily independent unit
Stabilizing Selection
Stabilizing Selection - favors the average or most common type of individual
Analogy
Structural or behavioural similarity in terms of functions between unrelated species or organisms but do not share a common ancestral or developmental origin
Sympatric speciation
Sympatric speciation - Speciation within the same place
If the average thickness of a wolf's fur is 5000 hairs per cubic centimeter and the climate became colder, what would you predict about fur thickness in future generations of wolves? What kind of selection is this? a The average thickness would increase, directional selection b The average thickness would decrease, directional selection c The average thickness would stay the same, stabilizing selection
The average thickness would increase, directional selection
Which of the following are correlations? a The more I study (hours), the better my grades are. b My mood changes with the amount of time the sun is up during the day. c People sleep too much. d People are cowardly and there are ants.
The more I study(hours), the better my grades are My mood changes with the amount of time the sun is up during the day
Gene pool
The total amount of all genetic variation in a species, all alleles and genes
Darwin noticed that some animals had traits that appeared to decrease survival or added some other cost that decreased an individual's fitness. These traits often only appeared on males compared to females who did not have these traits. For example, male peacocks have very large, beautiful feathers that make the males very conspicuous to females, but also to predators, increasing the male's chances of getting killed by the predator before he has a chance to mate. Evolution by natural selection should select against the males with these conspicuous traits because without showy feathers should survive longer than those with showy feathers. What kind of selection might maintain these conspicuous male traits despite the traits decreasing survival. a These traits should decrease in frequency due to natural selection by predators on the showy males. b These traits should increase in frequency due to natural selection by predators on the showy males. c These traits should increase in frequency in the population because female peacocks are more likely to mate with males with these showy traits despite the fact that the traits decrease male survival. d These conspicuous traits (e.g., extremely large, showy tail feathers) have no effect on the fitness of males.
These traits should increase in frequency in the population because female peacocks are more likely to mate with males with these showy traits despite the fact that the traits decrease male survival.
Vestigial Trait
Vestigial Trait - Structural relics that served other functions in evolutionary ancestors but now have lost their functions or have new ones.
Vicariance
Vicariance - separation or division of a group of organisms by a geographic barrier
Artificial selection
We select who breeds
Bottleneck (population or genetic)
When an originally large population has a sudden, dramatic reduction of population numbers
What evidence would disprove the idea of an intelligent designer? a Male humans frequently have problems urinating as a they age because their prostate glands enlarge over time, pressing on their urethra and restricting the flow of urine. b Humans have opposable thumbs, which allow them to grasp and efficiently manipulate objects like hammers. c The beaks of hummingbirds are remarkably similar in length to the flowers they pollinate. d None of the above.
a
What observations below are predicted by the theory of evolution? a Bacteria have evolved antibiotic resistance b Insects have evolved resistance to pesticides c Closely related organisms share more traits or alleles inherited from a common ancestor than less closely related organisms d New organisms suddenly appear
a b c
Placebo
a harmless pill, medicine, or procedure prescribed more for the psychological benefit to the patient than for any physiological effect
Which of these is capable of evolving? a a single bacterium b you c a population of fish in a lake
a population of fish in a lake
Population
a single species that is starting to occupy different geographical areas, or niches.
Model organism
a species that has been widely studied, usually because it is easy to maintain and breed in a laboratory setting and has particular experimental advantages.
Adaptation
a trait that provided an advantage in a given environment.
What are the forces (Mechanisms) besides Natural Selection that cause populations to evolve? a Genetic Drift b Migration c Mutation d Non-random mating
all
Adaptive radiation
an adaptation for one function then evolves a new function in a new context
Mate Choice
an evolutionary process in which selection is dependent on the attractiveness of an individual's phenotypic traits
When someone says, "It's only a theory", what do they mean? a The person is referring to a scientific theory that provides a logical explanation(s) that makes falsifiable predictions that can be empirically tested b An unsupported opinion c A theory is like a recipe d None of the above
b
What evidence suggests birds are descended from Theropod dinosaurs? a Birds have beaks and Theropod dinosaurs have teeth. b Bird's and many Theropod dinosaurs like Tyrannosaurus rex have/had feathers. c Archaeopteryx is an example of a transitional fossil because it shares both primitive (e.g., tail, teeth, colored body feathers) and modern characteristics (e.g. flight feathers, a beak, hollow bones) with theropod dinosaurs and modern birds, respectively. d Bird's, theropod dinosaurs, lizards, mammals, and frogs have four limbs.
b and c
Inbreeding
breed from closely related people or animals, especially over many generations
How does an adaptive trait evolve? a Mutation b Genetic drift c Natural Selection d Geneflow
c
One of the predictions of Darwin's theory of evolution is the order of the origin, evolution, and extinction of taxa (i.e., species, families, phyla) found in the fossil record. For example, Dinosaurs originated about 230 million years ago (mya) and went extinct 65.5 mya. What evidence in the fossil record would disprove the prediction that certain species are descended from previous ancestors? a The earliest fossils of bacteria are 3.5 billion years old. b A Trilobite (a crab-like invertebrate that originated 500 mya and went extinct by 250 mya) fossil is found in rocks 350 mya. c A modern human fossil is found inside a Tyrannosaurus rex coprolite (fossilized dung) from the end Cretaceous Period 77 mya, well before the first fossils of modern humans appeared 200 thousand years ago (kya). d Fossils of bacteria are found in rocks 190 kya old.
c
Gene
code for proteins
Fossil (Fossil Record) -
common ancestry in origination and extinction in fossil record
Correlation vs Causation Control group
correlation is an observed relationship between two variables
Sexual selection
differential mating success among individuals in a population
Say there is a population of monkeys that has a medium tail size. If, over several generations, the monkeys in this population now have either short tails or long tails, but very few in between, which type of selection has occurred? a stabilizing selection b directional selection c disruptive/diversifying selection
disruptive/diversifying selection
Extinction
end of an organism
Genetic Drift has the greatest effect on populations that are... a large b small c undergoing natural selection d reproducing quickly
small
Evidence suggests many people in the United States are opposed to the Theory of Evolution because __. a there is empirical evidence against evolution b some religious teachings question the concept of evolution c a belief in God is incompatible with the theory of evolution d thousands of scientists disbelieve the theory of evolution
some religious teachings question the concept of evolution a belief in God is incompatible with the theory of evolution
Allopatric speciation
speciation in different locations
During human evolution, birth weights that have been too low (‹5 lbs.) or too high (›11 lbs.) have been less fit (lower survival) than babies born in the middle range (5-10 lbs.). This is an example of: a directional selection b stabilizing selection c disruptive/diversifying selection d artificial selection
stabilizing selection
Biogeography
the branch of biology that deals with the geographical distribution of plants and animals.
Sexual selection affects . a how long an individual survives b the number of sexual partners an individual has c how many gametes an individual produces
the number of sexual partners an individual has
Statistical analysis
to estimate the significance of the result
Evolutionary speciation (i.e., one ancestral species splits into two descendant species) is usually gradual instead of instantaneous. a True b False
true
