Biol 3040: Part 1
How did conditions during WW1 operate to maintain exceptionally high virulence in teh influenza virus? a. Crowded conditions increased the effect of selection across hosts, leading to increased spread of the virus and increased virulence b. The lack of sterile conditions during wartime led to the exceptionally high virulence c. The high mobility of infected patients reduced the effect of selection across hosts, favoring selection within hosts and increased virulence d. Vaccines cause the evolution of increased virulence in the virus e. All of the above helped maintain high virulence in teh influenza virus
c
Which of these statements about vaccines is TRUE? a. Vaccines are usually injections of a diseases-causing virus in small enough amounts to trigger a strong immune system response without causing the disease. b. Vaccines developed using cells from monkeys or chimpanzees rarely work to prevent disease in humans c. Vaccines can be developed by altering the selective environment that a virus is adapted to d. Vaccines rarely function to prevent disease because viruses can adapt so quickly
c
Which pattern of allelic diversity would you expect to find if you hypothesized that humans first left africa and then spread across all of the continents. a. Allelic diversity would decline continuously as populations got farther and farther from africa b. Allelic diversity would be similar between Homo sapiens and Homo neanderthalensis but different from Homo heidelbergensis c. Allelic diversity would be consistently low for populations outside of africa but high for populations in africa d. Allelic diversity is far too high to detect any pattern, because the human population is so large e. Allelic diversity would be higher as populations got farther and farther from Africa and as they adapted to their new habitats
c
What factors associated with the evolutionary biology of bacteria facilitate teh evolution of resistance to antibiotics? a. High mutation rates b. Horizontal gene transfer c. Sub-lethal doses of antibiotics d. All of the above facilitate teh evolution of resistance e. None of the above facilitates the evolution of resistance
d
Which features related to bipedalism do modern humans share with early hominin fossils? a. Similar anchors for muscles in the pelvis b. Downward-pointing foramen magnum c. Flattened toes d. All of the above e. None of the above
d
Which molecule(s) related to our emotions likely evolved early in our mammalian history? a. Oxytocin b. Dopamine c. Vasopressin d. All of the above e. None of the above
d
Which of these statements about antimicrobial peptides is FALSE? a. Antimicrobial peptides are produced by sharks and fight infections b. Humans produce antimicrobial peptides on our skin c. The genes controlling the production of antimicrobial peptides have undergone more evolutionary change than any other group of genes found in mammals d. None of the above is false e. All of the above is false
d
Which of these statements is TRUE? a. Because of gene imprinting, a child can be born with features that look more like those of teh father than the mother b. Because of gene imprinting, parents may be genetically predisposed to abandon their children c. Genetic imprinting results when a gene is exposed to environmental toxicants d. Beckwith-Wiedemann syndrome may result when both parents copies of an imprinted gene are expressed in their child
d
Why is understanding evolutionary biology important to the future of medicine? a. Because phylogenies can be used to predict which influenza viruses may be particularly likely to cause future epidemics b. By examining orthologs, scientists may be able to identify the underlying genetic architecture of human disease c. Evolutionary biology can guide the development of antibiotic treatments, antiviral drugs, and chemotherapy d. All of the above d. None of the above
d
___________: ratio of non-synonymous to synonymous substitutions
dN/dS
Which adaptations are more valuable to people living at high altitudes- mutations to EPAS1 or mutations to EGLN1? a. Mutations to EPAS1 because they confer higher survival rates in Tibetans than in Hans without those mutations b. Mutations to EPAS1 because mutations to EGLN1 reduce survival rates of Andean peoples relative to Tibetans c. Mutations to EGLN1 because they confer higher survival rates in Andean peoples than in Hans without those mutations d. No mutation is more valuable to humans, because mutations to these important genes would be harmful e. Neither mutation is more valuable; both confer fitness benefits to the populations where they occur
e
Which of these statements is FALSE? a. Efficient bipedal walking evolved before the species Homo floresiensis diverged from the closely related Homo erectus b. Efficient bipedal walking evolved before the species Homo floresiensis diverged from the closely related Homo sapiens c. Efficient bipedal walking evolved in Homo floresiensis after the species diverged from a common ancestor shared with Homo erectus or Homo sapiens. d. All of the above are false. Homo floresiensis is not related to either Homo erectus or Homo sapiens e. All of the above could be true depending on the phylogenetic hypothesis being employed.
e
Homo ___________ 1.5 million years ago: Early members of the genus Homo, emerging about 1.8 million years ago, had lost tree-climbing adaptations but had long legs and other traits efficient for walking and running.
erectus
Others argue that H. floresiensis is not a branch of H. sapiens, but of Homo __________. At some point hundreds of thousands of years ago, a population of Homo (blank) in Indonesia came to the island of flores and then evolved its small stature. Perhaps an early wave of hominins left Africa before the tall Homo ergaster anatomy evolved. The first migrants out of Africa might not have looked all that human.
erectus
o Human-chimp split ~6-7 mya o Many hominin lineages, all extinct but ours o Transition to grassy habitat favored bipedal locomotion. Bipedal hominins at least 4.4 mya. Many skeletal changes associated with bipedalism o Tool use by 2.6 mya, maybe as early as 3.4 mya o Homo __________, 1.8 mya, walking, running, bigger brains, more sophisticated tool use
erectus
Brain evolution: Early Homo sapien art suggests considerable brain power. Figurative art appears in the fossil record ~40,000 years ago, and cave painting ~20,000 years ago. -Powerful brains were an important adaptation in human __________.
evolution
Antibiotic resistance is a form of ______________
evolutionary rescue
Yi et al: adaptation to high altitude: SNP with high frequency in Tibetan population is located in a __________ of EPAS1. - Used Danes as the outgroup which shows you the ancestral state in the adaptation to high altitude
flanking intron (happen to catch one snip)
Homo _______________ is widely believed to be an extinct species in the genus Homo. The remains of an individual that would have stood about 3.5 feet (1.1 m) in height were discovered in 2003 on the island of Flores in Indonesia. Partial skeletons of nine individuals have been recovered, including one complete skull, referred to as "LB
floresiensis ("Flores Man"; nicknamed "hobbit" and "Flo")
___________: Infects 30-60 million people each year. Simple- a small membrane envelope enclosing just eight short pieces of RNA that comprise its entire genome
flu virus (influenza)
2-3 million years ago: Australopithecus Afarensis: Once an upright stance evolved in hominins, better walking also may have evolved as an adaptation to the emerging open habitats of Africa. As hominins became more efficient at traveling on foot, they could travel farther and find more ________. Also walking upright would have helped them stay cool, moving in open habitats instead of dense forests, they would have been pummeled by direct sunlight, standing up right would expose less of their skin to the sun.
food
Evidence for gradual change toward bipedal locomotion through _________ records. Ancient relatives (hominins) were becoming better adapted to walking bipedally; over 7 million years.
fossil
These are the 3 races of humans! Most humans fall into non-African clade (most derived group), we are all basically the same race If a small band of individuals dispersed out of Africa and spread, multiplying in number and expanding steadily in range as they did so, then we might expect to find high levels of allelic diversity in Africa, and a lower -but consistent- level of allelic diversity elsewhere. The loss of diversity would have occurred with the initial ______________ event, but large population sizes would have minimized subsequent losses of alleles afterward.
founder
Some scientists argue that Homo floresiensis was actually just a population of Homo sapiens. The small brained Homo f. lacks a number of defining traits of humans like a large brain- could have small stature and brain due to disease- a ___________ disorder.
genetic
Outbreaks are often limited ________________ because highly virulent pathogens do not readily transmit to new hosts
geographically
Environmental change during hominin evolution: Seven million years ago there were grasslands with sparse trees existing at these sites (Ethiopia and Kenya). The woody cover increased over the next few million years and reached its greatest extent about 3.6 million years ago, when the sites were 40-60 percent woody cover. Then the woods began to retreat and by 1.9 million years ago no place was left with more than half woody cover so now the area was more ___________. The environment continued to open up and the trend continues to this day.
grassy
More Neanderthal _________ in Asians and Europeans. Percent Neanderthal varies across genome, and Neanderthal alleles under-represented on X chromosome
haplotypes
Archeologists found the butchered bones of wild horses. It's possible that Homo ________________ drove these horses into a lake and then killed them with their spears. This type of hunting suggests that the ability to cooperate in a sophisticated way had evolved in hominins. The tools they left behind show that they had moved beyond the hand axes their ancestors had used for over a million years.
heidelbergensis
Homo _______________: Hominin fossils from Africa that date back to around 600,000 years ago show clear signs of diverging from homo erectus- including the size of their brains. These hominins once again expanded out of Africa to Asia and Europe. As they spread, they left behind some of the earliest evidence that hominins could hunt. More evidence for hunting comes from the tools they made. (also chased big animals off cliffs, they were butchered later).
heidelbergensis
In addition to the wooden spears in Germany, they have also discovered a wealth of stone tools made by Homo _________________. The hominins made these so called Levallois tools by knocking off bits of a rock until they achieved a broad, flat shape. Then they delivered one sharp blow across the top of the rock, shearing off a large flake. They used tools to cut food and plant material, and hey even may have attached them to the ends of spears. They built simple shelters and made fires.
heidelbergensis
Neanderthals diverged from Homo ________________, they evolved in Europe and Asia. In neanderthal technology they used Levalois tools, mammoth bone huts, and cooperative hunting.
heidelbergensis
Worldwide travel may alter the selective environment of pathogens, favoring __________ virulence
high
Evolution and cancer: Many mutations within a cancer clone. Mutations may be pathogenic, they may increase the mutation rate, or they may simply be ______________. Difficult to sort out which is which!
hitchhikers (neutral)
Neanderthals and modern humans form separate _____________ groups
monophyletic
Within a single host, pathogens can replicate many times, _________, and evolve in response to natural selection. Diagram shows how related HIV viruses infected nine people and diversified inside them. As a result of this evolution, the viruses were better able to avoid the host's immune system and resist HIV-fighting drugs.
mutate
Because humans were frequently bottlenecked around the world, drift and _________________ were more prevalent than selection.
mutation-selection balance (important recent human evolution)
Evolution of antibiotic resistance within a single patient: In 2000 a patient known as JH developed an infection of Staphylococcus aureus. Doctors took a series of blood samples and identified the new ____________ that arose in the bacteria over the course of the infection. Mutations that conferred more resistance to antibiotics were favored by natural selection.
mutations
Flu virus: Each infect cell can make anywhere from 100,000 to 1 million new copies of the viral genome, which are then packaged into new membrane envelopes and escape the cell to infect a new host. During this explosion a vast number of mistake get made. The influenza virus accumulates ____________ so fast that they are often called mutant swarms.
mutations
The ancestors of non-Africans had unusually high numbers of certain alleles, including some that cause diseases. One of these diseases is ___________.
myotonic dystrophy
DM1 is the most common form of ________________ diagnosed in children, with a prevalence ranging from 1 per 100,000 in Japan to 3-15 per 100,000 in Europe. The prevalence may be as high as 1 in 500 in regions such as Quebec, possibly due to the founder effect. In most populations, DM1 appears to be more common than DM2. However, recent studies suggest that type 2 may be as common as type 1 among people in Germany and Finland
myotonic muscular dystrophy
Evolution and cancer: Somatic cell-line evolution of cancerous cells demonstrates how ___________ can be "short-sighted"
natural selection
The climate of Europe was harsh at this time, the Ice ages brought glaciers over the northern edge of the continent and turned the southern regions into dry wastelands. Over time, natural selection altered the bodies of these European hominins. The legs became stubby, chests wider, the bodies more muscled. BY about 300,000 years ago, fossils indicate they had become markedly different from the more slender hominins in Africa, these European lineage of hominins eventually evolved into a new species known as Homo _________________
neanderthalensis (neanderthals)
Environmental change during hominin evolution: Colleagues measured the carbon isotopes in the soils, this could accurately predict the percentage of woody plant cover from the isotopes alone. Then they began to analyze fossilized soil called ____________. They studied 1300 samples of (blank) that formed over the past 7 million years from two regions that have yielded some of the richest troves of hominins: The Awash Valley in Ethiopia, and the Omo-Turkana Basin in Kenya.
paleosol
Other founder effects: Descendants of the Bounty mutineers- a variety of genetic disorders. Had high frequency of color blindness. Amish- have a high frequency of ___________
polydactyly
Tools of evolutionary biology used to identify genes under selection in tumors: sequences of 772 breast cancer genomes, many genes under ______________ selection, including large proportion of globally expressed "house-keeping" genes
positive
The immune systems co-evolves with pathogens: - Parasites exert strong ___________ pressure on hosts (Pathogens adapt to their hosts, and their hosts in turn adapt to the pathogen.) - Human history is riddled with course-changing events related to the transmission of pathogens (Mutations that improve the defenses of hosts are strongly favored by natural selection)
selection
Early Homo sapiens displayed increasing levels of creativity: Humans in Africa began to show signs of ________________, such as pierced snail shells that might have gone on a necklace. In south Africa 60,000 years ago, humans made water containers out of ostrich eggs and decorated them with geometric patterns.
self-expression
Neanderthal artifacts reveal sophisticated behavior: Their tools were advanced, and they colored ___________ with pigment and drilled holes into them, perhaps to string them on necklaces. About 30,000 years ago though, the last traces of Neanderthals vanish from fossil record.
shells
Transition to bipedalism: - _______________ - Stress reduction - Energy storage and shock absorption - Stability during plantar flexion - Stride length
stabilization
Myotonic dystrophy is inherited, practically non-existent in _______________. Always deadly, small group of people that left Africa must have had a number of individuals that had the alleles for myotonic dystrophy that they passed down to future generations.
sub-Saharan Africa
Tools suggest diet of hominins: 1.8-1 million years ago - bone tools used for digging, hominins fed on __________.
termites
Early hominins had brains the size of a chimpanzees. About 2 million years ago hominin brains began to increase, and after 1 million years their growth accelerate. Today humans have brains about _______times the size of those earliest hominins.
three
Over the course of their evolution, hominins increasingly came to depend to depend on _________ to get their food. Chimps and other apes are adept at (blank)making, its likely that early hominins continued this tradition. This use of (blank) may have emerged as early as 3.4 million years ago. Bones associated with hominin settlement, scrape marks on bone (sharp rock used to cut meat away from the bone), could also get scrapes after death from being tumbled around.
tools
Public health efforts can select for less virulence by reducing _____________ - Crowding selects for increased virulence
transmission
Esther Hermann compared the mental skills of 105 two-year-old children against those of 106 chimpanzees and 32 orangutans. The fundamental difference between humans and other apes is that we became "ultra-social". The ___________ hypothesis predicts that children rapidly develop social skills such as learning from others and understanding what other people know or don't know. Social intelligence drove the evolution of the human brain.
ultra-social
Ardipithecus ramidus 4.4 mya, Awash River, Ethiopia: Ardi likely walked __________ one million years before Lucy, the famous fossil skeleton whose species was regarded as the first member of the human lineage. Ardi took her first steps in the forest (lucy savannah). From the shape of Lucy's bones, scientists reasoned that the last common ancestor of humans and other great apes had resembled a chimpanzee; Ardi does not. Ardi adapted to life in the branches and on the ground.
upright
Environmental change during hominin evolution: More ________ posture (bipedal locomotion) favored in savannah, walking long distances instead of jumping from tree to tree, can see predators from a longer distance away standing upright versus hunched
upright
Competing selection pressures on virulence: Mobile ________ spread disease without mobile host, relax selection on transmission rate
vectors (mosquitoes)
Flu virus: Not only does the virus mutate at a high rate, but it also undergoes, a special form of horizontal gene transfer known as ______________. This can produce viruses with new combinations of genes not seen before. (blank) from one strain to another can produce viruses that can escape the vaccine.
viral reassortment
_______________- Degree of harm caused by a pathogen to its host (pathogens vary wildly in degrees of this)
virulence
2-3 million years ago: Australopithecus Afarensis: The feet still had some gripping ability, she could not run but could ______. The fossils pelvis had some of the same anchors for muscles found in humans- anchors that chimpanzees and other apes lack. The feet were also suited for bipedalism; it had 4 toes flattened to support its weight. Also retained traits that would have helped it climb trees, still an opposable big toe. Could not climb trees as well as chimpanzees.
walk
Evolution and cancer: Once cells begin to divide uncontrollably, they are favored by natural selection _________ the host
within
Evolution of virulence: __________ host- - host immune system (evade) - replication rate (favors virus genotypes that replicate faster than their rivals, fast-replicating genotypes may also be the most virulent)
within
Source of selection ________ a host: - Ways to evade host, mortality rate (host immune system) and reproduction rate (reproduce rapidly)
within
Selection _______ host favors rapid replication (increased virulence)
within (competition within hosts)
Evolution of virulence: When the population of Australian rabbits was dense, ____________ viruses could more from one host to the next. The most virulent strains reproduced fastest in the rabbits, and they could still spread despite killing their hosts. But in time, the virus killed off so many rabbits that its host population thinned out. Now virulent strains of the virus tended to become extinct because they killed rabbits without being transmitted to another one. Selection began to favor less virulent strains. The result was an unstable balance and intermediate levels of pathogen virulence.
Myxoma
The last ______________ died out some 28,000 years ago. They could hunt elephants and rhino's, could fashion sophisticated stone tools, buried their dead.
Neanderthal
___________ is a form of ecological specialization that allowed hominins to find calories and protein that many other animals couldn't get.
Toolmaking
Early Homo sapiens were culturally diverse: __________ acquired local flavor, but humans also began trading their (blank), and some of them ended up hundreds of kilometers from where they had been made.
Tools
Environmental change during hominin evolution: True or False- The changing environment likely spurred a dramatic transformation in the way hominins moved about.
True
True or False: Mutations that increase fitness of young reproductive animals will be favored, even if they decrease the fitness of older post-reproductive animals
True
______________: - 1.5 million years ago - At age 12, already 5'3" - Stiff feet, barrel chest, long legs, narrow hips, relatively large brain - Assigned to our own genus, Homo, Homo ergaster. - Homo were good runners- fully committed to walking over climbing
Turkana boy
Prairie voles form strong bonds with their mates, while their relatives, the meadow voles, mate with many females. ______________ plays a critical role in driving the social behavior of prairie voles, and they have higher levels of expression of a (blank) receptor (AVPR1a) in their ventral forebrains than meadow voles do. Artificially increasing this gene in the forebrains of meadow voles (AAV) is sufficient to induce pair bonding behavior, effectively switching the mating system of this species from polygamy to monogamy.
Vasopressin
_______________ and oxytocin are important hormones for human emotions and social behavior. Homologs of these molecules can be found in other animals, where they play similar roles in behavior.
Vasopressin
Over the course of primate evolution, the connections between the frontal and temporal lobes became denser. Monkeys use Broca's area to interpret the calls of other monkeys. _______________ can make several different calls, each of which has a distinct meaning. hearing alarm calls activate Broca's area.
Vervet monkeys
Homo erectus 1.5 mya: When these hominins reached their prey, they brought with them new kinds of tools. They created large "hand axes" by carefully chipping away large rocks to create teardrop shapes. These new tools are known as ____________ technology- found in association with Homo erectus remains. Include oval hand axes, display more sophistication in construction than Oldowan tools. Probably used these so-called hand axes to butcher animals, cut wood, and gather roost and other plant foods.
Acheulean
In the brains of subjects with a working version of FOXP2, __________ became especially active (large orange spot on the left side of the unaffected brain)
Broca's area
_________ occurs when cells divide uncontrollably
Cancer
_____________ evolution involves competition among clones and "dispersal" to new habitats. - (blank)-clone evolution takes place within tissue ecosystem habitats. These habitats have evolved over a billion years to optimize multicellular function but restrain clonal expansion of renegade cells.
Cancer
______________ in 1747, recognized that humans and other primates shared a number of anatomical traits, from their forward-facing eyes to their gripping thumbs.
Carl Linnaeus
An example of an antagonistic pleiotropy would be a. A gene that produces a protein that can stop cells from turning cancerous but damages tissues that may be more likely to become cancerous later in life b. A gene with two alleles: one that increases susceptibility to cancer and one that decreases it c. A developmental gene that is influenced by the environment d. A mutation that produces a protein that can enhance development both early and later in life
a
How does MHC function in mate choice in humans? a. Males whose MHC genetic diversity is dissimilar to a female's are more preferred than males whose MHC genetic diversity is similar b. Women with high MHC tend to have sex for the first time at a younger age and to have more sexual partners c. Males that are more physically attractive have less MHC genetic diverstiy and are preffered by females d. Males that smell better to females have more MHC genetic diversity adn are preferred by females
a
Death rates from infectious disease has dropped dramatically. At the same time, rates of _________ and autoimmune diseases have risen in industrialized settings.
allergies
An artist's rendering of ________________, an early primate relative that lived in North America about 56 million years ago. Their fossils indicate early primates co-evolved with flowering plants. Used hands for better access to food on branches!!! Natural selection says the individuals that can get farther out on the branch can get more food and have more babies
Carpolestes
____________ history with pathogens leads some populations to be more resistant.
Co-evolutionary
Australopithecus sediba: sister to Homo? Some traits were ancestral, found in other australopiths, others had previously been found only in Homo. It had long, australopith-like arms, but its hands were short like our own. It had a projecting nose similar to ours, but still had a tiny brain. A. sediba was either the _____________ of Homo or one of the closest relative to the clade. (They think it is a sister species to the genus Homo) The combination of traits in A. sediba some of which it shares with Australopithecus afarensis (Lucy) (3.2 mya) and some of which it shares with more derived, human-like hominins, Homo erectus (1.6 mya)
ancestor
Huntington's disease illustrates ________________, it doesn't effect people until later in life. If the alleles causing the disease affected people throughout their lives, the alleles would be much rarer than that. Since it effects people later in life, they have enough time to raise children, passing on the disease-triggering alleles to the next generation before they die.
antagonistic pleiotropy
Natural selection has favored alleles for survival and reproduction at younger ages. When these alleles trade off early fitness benefits with later problems, aging is the result= ___________________
antagonistic pleiotropy
Competing selection pressures on virulence: _____________ and travel increases transmission, relaxes selection on transmission rate
Crowding (refugees packed in camp)
___________________- Over half of all Americans will be infected with this before the age of 40, in most people no symptoms; in some fever, fatigue, and swollen glands but deafness, blindness, or mentally disabled if infected before birth. Medically important, pregnant women are tested for it.
Cytomegalovirus (human herpesvirus 5)
In his 1871 book The Descent of Man, ___________ argued that these similarities were evidence that humans and primates have a common ancestor. He noted that apes are most similar to humans in that they are large bodied, have relatively big brains for their bodies, and have a vestige of a tail like humans. He had no human fossils to examine as he developed his theories.
Darwin
Farms are another source of resistant strains: - Chickens fed sub-therapeutic doses of oxytetracycline - After 2 weeks, 90% of experimental chickens excreted ____________ resistant bacteria - By 4 months, resistance transmitted to controls - By 6 months, fecal samples of farm workers also contained resistant bacteria
antibiotic
Resistance increases with frequency of ____________ use
antibiotic
The tools at Gona are the earliest evidence of a distinctive stone-tool industry that lasted from 2.6 to 1.5 million years ago. It's known as the ____________. The shapes of the tools show how they were made, by striking off flakes from large round rocks. Hominins used tools to butcher scavenged meat and possibly to fashion wooden tools.
Oldowan
__________ tools are the earliest stone tools
Oldowan
______________: Mutated versions of proto-oncogenes
Oncogenes
____________: the level of virulence that maximizes rate of transmission for the virus
Optimal virulence
Yi et al: adaptation to high altitude: ____________ is the probability that we observe an allele frequency difference at least this big (0.000001) by chance. They need to account for the number of genes because you have to set a threshold for significance because you will get a lot of false positives.
P-value
The geographic distribution of some alleles reflects their ongoing selection. A: the FY*O allele confers resistance to _______________. It is prevalent or even fixed in Africa but virtually absent on other continents. B: Ancestral and derived alleles of SLC24A5. The derived form of the allele has been linked to light skin color in Europeans.
Plasmodium vivax malaria
_____________: gene affects more than one phenotype
Pleiotropy
Scientists compared genetic variation in a sample of Han Chinese and Tibetan populations. Most alleles occurred at similar frequencies in the two populations (diagonal line). Two alleles that are significantly more common in Tibetans than in the Han occur in the __________ gene (arrows). This gene is involved in acclimation to high altitude. These high frequencies suggest a history of directional selection on this gene associated with the move to extreme altitude.
EPAS1
__________: a combination of alleles at adjacent locations on a chromosome that are inherited together. A haplotype may be one locus, several loci, or an entire chromosome depending on the number of recombination events that have occurred between a given set of loci.
Haplotype
___________________, an experimental type of immunotherapy for the treatment of autoimmune disorders by means of deliberate infestation with parasitic worms (including hookworms, whipworms and threadworms). - Target diseases include asthma, Crohn's disease and inflammatory bowel disease.
Helminthic therapy
_______________ was was present in early hominins! Branching tree pattern of virus mirrored primate tree; are exactly the same because they evolved at the same time. They were coevolving with their hosts!!
Herpes virus
______________ and increased mutation rates make it difficult to identify causative mutations (often thousands of genetic differences between cancer and healthy tissue)
Hitchhiking
_______________: positive selection on one allele leads increase in frequency of linked alleles - 1. Initial mutation increases subsequent mutation rate, so early stage tumor, already has some allelic differences with healthy tissue - 2. New mutation increases cell division
Hitchhiking
______________- members of the clade containing humans (Homo), chimpanzees and bonobos (Pan), gorillas (Gorilla), and orangutans (Pongo). Commonly referred to as great apes.
Hominids
________ evolution included increasing complexity of tools, changes in diet
Hominin
Earliest hominins found in Africa: Sahelanthropus tchadensis is an extinct hominine species that is dated to about 7 million years ago, possibly very close to the time of the chimpanzee/human divergence, and so it is unclear whether it can be regarded as a member of the ______________ tribe. Few specimens are known, other than the partial skull nicknamed Toumaï ("hope of life").
Hominini
First expansion out of Africa - 1.8 million years ago: - First migration out of Africa did not include our own lineage - __________, a close relative (or possible descendent) of H. ergaster, spread as far as Indonesia. Other species arrived in Europe by 1 million years ago.
Homo erectus
_______________: normal genes that can cause cancer when they acquire certain mutations
Proto-oncogenes
Neanderthals went extinct ~40,000 years ago: Probably due to, - Experienced *violence from modern humans*, spear tip made by a modern human - Modern humans were better at hunting and tended to outhunt game populations, left Neanderthals with little food. So there was a *competition with modern humans* - Climate was warming from the ice age to modern temperatures we see today= *climate change* - *_______________ with modern humans*
Hybridization
Competing selection pressures on virulence: __________ makes transmission harder, selects for reduced virulence
Hygiene (washing hands)
________________: early exposure to pathogens is important
Hygiene hypothesis
___________ itself can drive the evolution of disease
Medicine
Apes branched off from Old World monkeys during the __________ period, about 30 million years ago.
Miocene
_______________: Strains infecting humans were a monophyletic group. The strains are very similar, they all have a recent shared ancestor, it crossed over to humans only once. It was sister to the strains of viruses shared by civets (cats). Ultimate host of (blank) was from a bat, entered civets since 2001. Bats --> Civets --> Humans
SARS
In 2003, panic swept southeast Asia as a new disease, known as ________ broke out. The disease was not the flu, not pneumonia, or any other known disease.
SARS (Severe Acute Respiratory Syndrome)
_____________: strong selection can "sweep" a favorable allele to fixation within a population so fast that there is little opportunity for recombination. In the absence of recombination, large stretches of DNA flanking the favorable allele will also reach high frequency.
Selective sweep
______________ create regions of low diversity Width of low diversity region depends on strength of selection and recombination rate
Selective sweeps
All of ____________ injuries show signs of healing, so none of them resulted in his death. In fact, scientists estimate he lived until 35-45 years of age. He would have been considered old to another Neanderthal, and he would probably not have been able to survive without the care of his social group.
Shanidar 1
Skull of ______________ Age: Between 45 000 and 35 000 years old Species: Homo neanderthalensis Through examining his skeletal remains, scientists found evidence that at a young age, (blank) experienced a crushing blow to his head. The blow damaged the left eye (possibly blinding him) and the brain area controlling the right side of the body, leading to a withered right arm and possible paralysis that also crippled his right leg. One of (blank) middle foot bones (metatarsal) on his right foot shows a healed fracture, which probably only enhanced his noticeable limp.
Shanidar 1
Mutations that provide resistance to malaria have been able to spread quickly in regions where the disease is especially common. _____________ is the by-product of one of those defenses. People suffer from this when they inherit two copies of an allele called HbS. It's possible that Plasmodium parasites can't grow as fast inside red blood cells with the HbS allele, or that infected cells are eliminated from the body faster. Human populations where malaria is prevalent show much higher frequencies of the HbS allele than other areas where malaria is less common or absent.
Sickle-cell anemia
Evolution and cancer: ____________ mutations that disrupt normal checks on cell division can lead to cancer
Somatic
___________: 1918, Virus ravaged his patients' bodies fast, and it killed sometimes within a single day. The virulent strain had evolved and begun to spread within a local community. This particular virulent strain did not die out. It spread to the second-largest training camp in the country and within 3 weeks more than 1100 soldiers were hospitalized with the (blank). Troops began shifting between camps, and from camps to the European front. Virus swept across Europe and then china, to new Zealand and Australia, and back to the US. As the virus spread it continued to evolve and became increasingly virulent. About 100 million people died. - crowded conditions drive flu outbreaks
Spanish flu
Broca's area and many other regions of the cortex that help process language are all joined together by a bundle of nerve fibers. If this bundle, called the ______________ is damaged, the ability to speak is damaged too. The (blank) is a bundle of nerve fibers essential to human language.
arcuate fasciculus
How important are mutations in the evolution of HIV once the virus has infected a host? a. Very important. Mutations will weaken the virus, allowing the immune system to mount a resoonse b. Very important. Mutations give rise to variation that can generate fitness advantages within a host and lead to evolution of HIV resistance to immune system responses c. Not important. Mutations are always deleterious; a virus experiencing mutations would eventually be destroyed by the host's immune system d. Not important. HIV cannot evolved once it has entered a host, because it does not reproduce sexually. e. It depends. Mutations are deleterious, so they could weaken the virus if the host is given the right combination of HIV-fighting durgs
b
If Sahelanthropus dates to around the time of the human-chimp split, is it more closely related to chimps or humans? Do scientists... a. Know b. Do not know
b
The hypothesis that contends that the evolution of large brain size in modern humans is a result of our ability to learn from others is called a. The cultural evolution hypothesis b. The ultra-social hypothesis c. The foramen magnum hypothesis d. The social ape hypothesis
b
Which statement is NOT a prediction of the hygiene hypothesis? a. Children who frequently play outside should develop allergic diseases less often than children who don't play outside b. Children who never wash their hands or bathe will be less likely to develop immune disorders than children who wash regularly c. The more infectious diseases an individual is exposed to as a child, the less likely that person will be to develop immune disorders as an adult d. Extensive use of antibiotics as a child may affect how the body responds to future bacterial invasions e. Pathogens that have long historical associations with humans, such as H. pylori, should be more positively related to immune system function than pathogens with more recent associations
b
Piecing together relationships is challenging. Extensive morphological homoplasy. There were about ______ hominin species!
20
If we could pay a visit to Africa 2 million years ago, we would observe ______ different hominin species and perhaps more. They would have run the gamut from the gorilla-like Paranthropus, grinding away at plants with its massive jaws, to the small and slender toolmaker Australopithecus habilis. They were fundamentally similar, they were short, and they still had small brains- closer to those of chimps. They were bipedal apes.
4
Neanderthal haplotypes <100 kilobases in size, 1-___% of the genome. - Over representation of Neanderthal alleles in genes for keratin filaments - Under representation of Neanderthal alleles, on the X chromosome, genes expressed in the testes, and in coding regions in general
4
_____________: occurs when two or more previously isolated populations begin interbreeding. This results in the introduction of new genetic lineages into a population.
Admixture
All genetic evidence supports the hypothesis that modern humans evolved in _________
Africa
All living humans can trace their mitochondrial DNA to a single female who lived in __________ 150,000 years ago. Modern humans emerged about 200,000 years ago.
Africa
Most of the early Homo fossils found outside Africa have a similar body plan- they are tall and slender. The lineage that would give rise to Homo sapiens remained in ________.
Africa
Where are the 3 major clades of modern humans found? - 3 deepest divergence among humans all occurred in _______, this is what you expect to see the greatest genetic diversity in the area where they first evolved - Race as we know it is socially constructed
Africa
It was from the ____________ diversity of Miocene apes that survived that our own lineage evolved- morphology then DNA
African
_________________: gene has positive effects on one phenotype and negative effects on another
Antagonistic pleiotropy
___________ branched off from Old World monkeys during the Miocene period, about 30 million years ago. They were medium to large primates, lacking tails and adapted for climbing in trees by gripping branches with both hands and both feet. Initially, they thrived across Europe, Africa, and Asia. Over time, many Miocene (blank) species became extinct. In Europe the (blank) disappeared completely, Asia a few survived, and Africa a greater diversity of (blank) survived.
Apes
Evolution of virulence: __________- is one of the most virulent pathogens known, inducing massive hemorrhaging and killing up to 90 percent of the people it infects. The virus is probably endemic to bats, but the bats can spread the viruses onto the fruits they feed on. Transmission occurs from contact with body fluids, and this pathogen can quickly spread to infect families and even entire villages before people realize what is happening. However, because it kills human hosts quickly, the virus has yet to spread beyond its local points of origin, and quarantine, masks and gloves, and proper handling of bodies is sufficient to contain outbreaks until the strain becomes extinct.
Ebola
DNA suggests some interbreeding between Neanderthals and non-African humans. Neanderthals interbreed with ancestors of _________________ and Asians
Europeans
___________: Facilitates a part of neural development first gene ever clearly linked to language - Broca's area plays a pivotal role in processing language, adaptations evolve from old parts as they're modified for new uses
FOXP2
True or False: All non-Africans are descended from a relatively large number of individuals.
False (small)
Features of human skeleton that make us better suited to bipedal locomotion: -___________ - Angle of hip joint (wider) and different muscle attachment site - Center mid section - Elongated muscles and bones - Foramen magnum (hole in the base of the skull that points straight down in humans, and extends back in chimps)
Flat feet
_________virus evolves rapidly to evade our immune system
Flu
Human biology changed very little in the past 40,000 years. Few adaptive differences between populations: (human technology has changed a lot) - Not that much time - __________ diversity relatively low - Few difference in optimum phenotypes among locations as humans spread around the globe (same facial features)
Genetic
________________: individuals from two or more previously separated populations begin interbreeding.
Genetic admixture
Alleles can spread to fixation in populations thanks to random luck. ___________ is especially strong in small populations as well as during founder events and population bottlenecks. Even when small populations expand into large ones, they can still have a low amount of genetic diversity due to (blank). - Humans expanding out of Africa went through a similar bottleneck.
Genetic drift
______________ the transfer of alleles from one species to another as a result of hybridization between them and repeated backcrossing.
Introgression
______________: in genetics is the movement of a gene (gene flow) from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species.
Introgression
What evidence most clearly supports the hypothesis that Broca's area evolved from regions in the brain that may have processed simple sounds before it evolved into a language center? a. Homologous regions to Broca's area that are triggered by specific sounds and not others are found in living primates like macaques. b. Mutations to the FOXP2 gene cause reduced activity in Broca's area and have devastating effects on language c. Strong selection drove the FOXP2 gene to fixation in the common ancestor of humans and other great apes d. The development of other types of complex cognition, such as tool making ability, resulted from intense social interaction e. All of the above are evidence that Broca's area evolved in a common ancestor
a
Why do Homo sapiens and Homo neanderthalensis share DNA if not from common descent? a. Because Homo sapiens and Homo neanderthalensis hybridized during their coexistence b. Because techniques for examining DNA are imperfect c. Because homo sapiens and Homo neanderthalensis are not really distinct species d. Because of sampling error in the methodology
a
Why does complete color blindness affect the population of the island of Pingelap over 1500 times more than that of the United States? a. Because of a population bottleneck that reduced the population to 20 individuals b. Because achromatopsia is caused by excessive exposure to sunlight c. Because so many people live in the United States, color blindness is hard to diagnose d. All of the above are causes of teh high rate of color blindness e. None of the above is a cause of the high rate of color blindness
a
Evolution of virulence: __________ host- - How sick is host (how sick it makes the host) o Mode of transmission (coughing, sneezing) o Favors reduced virulence; If it makes you so sick you stay home (cant spread as much) - Host behavior (increase spread of pathogen) - Vectors o Mosquito, easily able to transmit different diseases (can have high virulence aka malaria) - Incubation period, time when you are infected and walking around spreading symptoms without knowing you are sick
between (across)
Selection ________ hosts favors reduced virulence (viral genotypes with lower virulence often do a better job at getting transmitted from one host to another)
between (transmission to new hosts)
Change to open habitat may have selected for __________
bipedalism
Homo erectus 1.5 mya: The flaring shape of australopithecine rib cages suggest a massive digestive system for eating mostly plants. The narrow rib cage of Turkana boy, suggests a shorter digestive system- perhaps one that was adapted to a diet with more meat or more energy-rich tubers. This shift was crucial to the expansion of the hominin __________. These requires huge amounts of energy. As the guts of hominins shrank, they were able to direct energy away from maintaining their intestinal tissues, and toward an expanding (blank).
brain
_____________ clones evolve through the interaction of selectively advantageous 'driver' lesions, selectively neutral 'passenger' lesions and deleterious lesions (a 'hitchhiker' mutation in evolutionary biology is equivalent to a passenger mutation in cancer biology). In addition, 'mutator' lesions increase the rate of other genetic changes and micro- environmental changes alter the fitness effects of those lesions.
cancer (Cancer-suppressive mechanisms relegate most cancers to old age, when they have little effect on the reproductive fitness of their hosts.)
Cancer evolves with a patient: A lineage of hematopoietic stem cell acquired mutations, including the 5 on the left. The cancerous cells became more common, as indicated by the increasing width of the gray shape. Within this lineage, some cancer cells acquired new mutations, two of which are represented by the yellow and purple dots. The descendants of the cells with these mutations rapidly became more common, thanks to natural selection. Chemotherapy reduced the population of the of all these lineages but cluster 4 cancer cells (orange line) rebounded. New mutations within this lineage then produced cells that came to dominate the population. The cancer thus evolved resistance to ______________.
chemotherapy
Common ancestor of humans and _____________ most likely lived 7.2 million years ago
chimpanzees
When conquistadors arrived in the new world, they brought with them new deadly diseases such as the measles and smallpox. In Europe, these pathogens and their human hosts had been in a ____________ arms race for centuries. As a result, Europeans had some resistance to the disease. The pathogens began to infect the people of the new world whose immune systems had not been part of the arms race and they wiped out an estimated 90 percent of the residents of north and south America in the first few decades after contact with Europeans. Without (blank) history, hosts may be defenseless.
co-evolutionary
All of the humans share a recent common ancestor, which molecular clock estimates place at roughly 150,000 years ago. All Neanderthals share a recent common ancestor to the exclusion of humans. Thus the evidence from DNA- both modern and ancient- indicates that Neanderthals and humans represent two separate lineages of Homo descending from a _____________.
common ancestor (Neanderthals (top) formed their own monophyletic clade in this analysis. This analysis indicated that humans and Neanderthals diverged from a common ancestor.)
Phylogenetic tools can identify the source of new pathogens: SARS virus was most closely related to pathogens called _____________, which can cause colds and stomach flu. Scientists suspected that SARS had evolved from a virus that infects animals. They began to analyze viruses in the animals that people in china have regular contact with. As they discovered new viruses, they added their branches to the SARS evolutionary tree. Big breakthrough with the discovery of a closely related virus in cat-like mammals called civets, but further research revealed that civets are not the main host for the viruses that gave rise to SARS in humans. Sars virus evolved from a family of viruses that circulates in bats!
coronaviruses
Is natural selection currently favoring lower cholesterol levels in women? a. No. Cholesterol is necessary for body maintenance and growth and generally causes heart disease only later in life; it is likely a result of senescence with very little effect on reproduction in women b. No. Individual women vary in the tendency to metabolize cholesterol, but that variation is largely due to diet, and diet is more related to culture- not genetically transmitted c. Yes. Women with greater body weight have greater reproductive success and lower cholesterol d. Yes. Individual women vary in the tendency to metabolize cholesterol, this ability has a genetic component that can be transmitted to offspring, and individuals with a genetic tendency for low cholesterol have greater reproductive success than women with a genetic tendency for high cholesterol
d
2-3 million years ago: Australopithecus Afarensis: The diet of early ____________ changed. (blank)faced an unreliable food supply. In the wet season fruits are abundant and freshwater pools swell with rain. In the dry season, the fruits vanish and only tough seeds survive, while drinking water becomes scarce. Early hominins had smaller incisors and canines, and their molars were bigger and flatter. The enamel on their teeth was also thicker. These changes may have reflected a shift from tough fruits and plant matter to seeds, nuts, and other foods that the hominis could have eaten with strong, crushing forces.
hominins
7 million years ago, fossil records reveal apes with traits that ally them more closely to humans than other living apes - the ____________. The (blank) offered still more anatomical evidence for a kinship between humans and other apes.
hominins
Bacteria can also acquire genes through ________________, which can speed up the evolution of antibiotic resistance dramatically.
horizontal gene transfer
Evolution and Cancer: - All multicellular organisms are a form of cooperation. - Cooperation is subject to cheating (mutualisms must punish cheaters --> ____________) - Cooperation is favored because every cell has the same genome - But long-lived, multicellular organisms accumulate many somatic mutations
immune system
Increased mutation rate leads to genomic instability: Genetic and phenotypic variation are observed between tumors of different tissue and cell types, as well as between individuals with the same tumor type= _____________
intertumor heterogeneity
Increased mutation rate leads to genomic instability: Within a tumor, sub clonal diversity may be observed= ______________
intratumor heterogeneity
Humans did *NOT* evolve in a ____________-like progression At least four hominin species coexisted 2 mya
ladder
All hominin fossils older than 1.8 million years were discovered in eastern and southern Africa. Using the _________________, a number of scientists have made estimates of the hominid-hominin split. This phylogeny of primates is based on a combination of analyses of DNA and fossils.
molecular clock
Viral reassortment leads to rapid evolution: Once a bird flu virus does infect a person, it has an opportunity to adapt to living in humans. Reassortment can accelerate this evolution dramatically. If a bird flu virus co-infects a cell with a human flu virus, a new hybrid virus may emerge, carrying the lethal genes of a bird strain along with hemagglutinin genes adapted for infecting human cells. Such a virus may be both _________ and efficient at transmission.
lethal
Human populations underwent repeated bottlenecks as they colonized new areas of the globe: All non-Africans descend from a small population of humans who lived in Ethiopia. The farther populations are from Ethiopia, the _______ their allelic diversity. This decline reflects founder effects caused when small populations settled new regions of the world.
lower
Under-representation of neanderhtal ancestry on the X, hypothesis #1: Dobzhansky-Muller Incompatabilities: - alleles arise in allopatric populations which are favored in each of the separate environments, but incompatible with each other when the populations come back into contact - Under-representation of Neanderthal alleles in testis expressed genes and on the X could be due to selection against DMI's which decreased _________ fertility in Neanderthal-Human hybrids
male
This 40,000-year-old human _______________, found in a Romanian cave, has a mix of human and Neanderthal traits; genetic analysis suggest Neanderthal ancestor 4-6 generations back. - Jaw has combination of Neanderthal and modern human jaw features, it was a hybrid between Neanderthal and modern human - Great Great Great grandparent was neanderthal
mandible
The oldest fossils of ___________ date back to about 55 million years. DNA evidence- Most Recent Common Ancestor of (blank) 66-69 mya --> adaptive radiation of placental mammals at time of dinosaur extinction
primates
Hypothesis #2: Under-representation on X due to asymmetric hybridizations, mostly involving male Neanderthals - Use recombination clock to date samples - Size of the haplotype block decreases with time since admixture and with increasing ______________ rate
recombination
Dating ancient humans samples using the _____________________: - Combined carbon dating and haplotype dating - They took samples from archeological sites - Pretty good rating between carbon dating and genetic age in year
recombination clock
Flu virus: People with the flu cough and sneeze, projecting virus laden droplets into the air. Natural selection within our body favors viral genotypes that are the most efficient at ______________ themselves. These genotypes will be represented disproportionately in the infectious spray. They will therefore have the greatest likelihood of being transmitted to subsequent hosts.
replicating
Pathogens reproductive success depends on both their ____________ within hosts and their ability to infect new hosts.
replication
In the absence of an antibiotic, resistance mutations may have either no effect on fitness or a negative effect. As a result, they were relatively rare in pathogens at the dawn of the age of antibiotics. But the advent of those drugs abruptly altered the evolutionary landscape. Mutations that provided microbes with even a little resistance led to more ____________ success. As lineages of resistant microbes took over populations, new mutations emerged, some of which increased their resistance even more.
reproductive
The effectiveness of most antibiotics is short-lived: - discovered antibiotics made by fungi in early 1900s - not long after first became available, doctors reported that they sometimes failed - Some microbes carry pre-existing alleles that turn out to provide ______________ against antibiotics. (blank) can take many forms. Some mutations can make it harder for antibiotics to attack their targets inside the microbe. Some alter membrane pumps so that the microbes can flush the antibiotics out quickly before they cause serious harm.
resistance
Flu virus: We get the flu when the virus makes its way into our ______________ tracts. A protein that studs the surface of the virus, called hemagglutinin latches onto proteins on the host cell. Once inside, the virus genome recruits our cells' genetic machinery to mass-produce copies of itself.
respiratory
In Africa, Homo heidelbergensis gave rise to a new species- our own. A better preserved skull from Ethiopia dating back to 160,000 years ago, and has been dubbed Homo ______________.
sapiens idaltu