Evolutionary Principles, Hardy-Weinberg, and Fisher's Theorem Flashcards
approximately how many genes are there in the human genome?
25,000
what is hardy weinberg equilibrium? Explain its meaning. Does it ever occur?
genotype frequencies in a population will remain constant between generations without any outside disturbance, it will never actually happen doesn’t account for evolution
what are four major forces of evolution?
disruptive and stabilizing selection , gene flow, gene drift, mutation
what is the most important force preventing species formation in evolution?
selection is most important
what is the effect of drift upo a population’s overall genotype?
small poplation genes can disappear but larger pop genes stay but are not necessarily seen through phenotype
what is polygenic inheritance?
characteristics controlled by more than one gene: eye color, height
Explain how 2 populations can have entirely different phenotypes and yet contain the same genes in different frequencies, why are domestic dogs serve such an excellent example?
dominant vs recessive genotype,
gene frequency changes morphpology, dog breeds show targeted selection for certain traits
Explain what is meant by “background noise” in the expression of bony traits
there are some aspects of bone development in which exist as just “background noise” and did not evolved for a particular reason but just because it happened when something else developed. Adaptationism believes that everything is connected and has a purpose; there simply cannot be any kind of background noise
what muscle is responsible for the hypotrochanteric fossa of the femur?
gluteus maximus
what is an enthesis and explain how its “robusticity” does not nexessarily reflect the intensity of use of its inserting muscle during life
Enthesis is the site of attachment of tendon to bone, there can be a lot of genetics involved with inserting muscles, with little mechnical use having an effect on the structure of said muscle, but rather its interior strength
what is cartilage modeling and why is it important in analysing the skeleton? give an example.
fully mechnical concept, only changes to force to allow it to adjust to that force (example knuckle-walking)
are knuckle walking grooves most likely genomic or induced?
both genomic and cartilage modeling, combo of PTHtp loop, however I think that is mostly genomic (probably?)
how can the habit of squatting be detected in the skeleton?
squatting facet: evidence of front of tibia pressed against talus, double indiction in trochlear surface
Why are the meniscal grooves important in analyzing the knee of primates?
helps us determine bipedality in a primate
What is the bicondylar angle and what injury can be induced if it is excessively high?
aligns knee with foot under center of gravity, knee injury can be induced
What is Fisher’s Fundamental Theorem. Why is it so important in understanding the
evolutionary process?
rate of increase of any organism is equal to its genetic variance in fitness at that time
What is heritability–why does it not necessarily reflect the intensity of selection acting upon a
trait?
quality of a characteristic being transmissible from parent to human, determine response to selection but not intensity b/c some strong traits are not passed on but what to contribute to fitness to me modified
Who were the Denisovans? How were they “discovered”?
extinct species of archaic humans during paleolithic, found from DNA extracted from a girl’s finger bone in a cave in Siberia
What are spandrels–why are they so apparently prevalent in discussions of human
evolution?
spandrels: triangular gap in corner of an arch, in evolution they can be see as byproduct of evolution of some other characteristic rather than a direct product of adaptive selection; key to understand that not everything an animal develops has positive effect on their fitness due to a natural selection or adaption, byproducts are also formed
Explain why the length of the radial neck cannot readily be selected in order to improve the
moment arm of the Biceps brachii muscle. What is unusual about proximal versus distal growth
in the mammalian zeugopod.
neck length does not vary but radical length does depending on body size, this means that the radical neck does not help with improve in the movement of biceps brachii muscle because there is not growth place in radical neck
Does the morphology of KNM-ER-20419 suggest arboreal behavior in Australopithecus
anamnesis?
No, radical neck length negatively correlates with arboreality, adaption for REACH not bicep torque
Explain how Fisher and/or Gould would view “semelparous reproduction.”
What is the significance of a population “bottleneck”?
Loss of genetic variation that occurs after outside forces destroy most of a population, few individuals left to reproduce pass their traits on when then can thrive without competition of large population
What is inbreeding and why is it deleterious?
Inbreeding: mating of animals more closely related than average relationship within the breed or population, genes can disappear or be deleted because only particular genes are getting based on since they are very similar
What is a balanced polymorphism? What example does Stanford provide based on
phenotypic differences. If the differences are purely phenotypic, can they have any
impact on evolution?
Balanced polymorphism occurs when two different versions of a gene are in a population b/c individuals carry both versions are more likely to survive than those with 2 copies of one.
Someone carrying sickle cell anemia gene living in an area where malaria is an endemic (heterozygous and homozygous genotypes), can have an effect on evolution
What is homology? Give one or two examples in the vertebrate skeleton.
similarity in structure between different organism based on descent from common ancestor,
Example: four limbs of tetrapods, birds, bats, mice, and crocodiles all have 4 limbs while sharks and bony fish do not. ancestor of tetrapods evolved 4 limbs and its descendent inherited it
Explain why polygenic inheritance is a more likely explanation for a major difference in two
populations than mutation.
polygenetic inheritance produces specific trait that is influenced by 2 or more genes while mutation is change in DNA sequence. Polygenetic inheritance would cause more variations since it is determined by multiple genes therefore there can be A LOT of variation while mutation only changes a single gene usually
What is punctuated equilibrium?
hypothesis that evolutionary development is marked by isolated episodes of rapid speciation between long periods of little or no change (equilibrium)
What is inclusive fitness?
ability of an individual to transmit genes to the next generation including genes shared with relatives
