ANBI 139 Midterm
What is the total surface of the human skin?
2 square meters without the folds, 25 square meters with
How much larger is a human macrophage than a bacterium?
4 to 40 times larger
How many pieces of DNA are there in the nuclear genome of a human?
46, visible as chromosome when a cell is dividing
What is the model (most common among adults) age of death in living hunter gatherer societies?
70 plug years
What is iatrogenic disease?
A disease caused by medical professionals
What is an antigen?
A molecule that can be recognized by an antibody (immunoglobulin)
What is a monoclonal antibody?
A specific antibody made by one clone of B-cells (these can be isolated and the mass-produced by introducing the DNA sequence encoding this specific antibody into a cell line)
What is the enhancer (in the genome)?
A stretch of DNA that interacts with transcription factors and the promoter of genes to regulate their expression.
What is a haplotype?
A unique combination of DNA variants along the same strand of DNA
What is the haplotype in genetics?
A unique combination of genetic variants (alleles) along the same string of DNA on a given chromosomes
What is the disease called pellagra?
A vitamin deficiency stemming from the lack of adequate preparation of corn (lack of nixtamalization)
How long is the haploid genome of each of our cells and how many "letters" base pairs does it contain?
About 1 meter long and it contains 3 million bp
Where are people still most affected from indoor fire smoke inhalation?
Africa and India
Where are people still most affected from indoor fire smoke inhalation?
Africa and India, South East Asia
Why is Africa the only continent that still has such large numbers of wild animals?
African animals evolved with humans, so they're people smart. Large animals on all other continents when these bipedal primates with their efficient hunting tools arrived, so many died out
Why was one of the many negative effects of the transatlantic slave trade on global disease?
African infectious disease and their mosquito vector species arrived in the Americas.
What is one of the long-term negative effects of fire use on human health?
Air pollution causing lung and other diseases
Why can we call the body of an individual human a clone?
All body cells derive from the same fertilized egg and share the same genome.
Which of the modern online services relies heavily on reputation?
Amazon, Ebay, Airbnb
What do you call a disease in non-human animals caused by a human pathogen?
An anthroponosis
How could scientists determine what caused the epidemic of Cocoliti?
Ancient DNA studies of skeletons in mass graves data to the year of the outbreak
Which cell types in the human body activates recombination activating genes (RAGs)?
B-cells and T-cells of the immune system.
List two components each from the cellular and humoral immune system
B-cells and macrophages, antibodies, and complement
What does clonal selection in the immune system refer to?
B-cells that make antibodies which bind antigens as well, are allowed to replicate as clones, rapidly increasing the fraction of these B-cells over other, that fail to produce such antibodies
Why is the evolutionary tree of life made up of branches?
Because most of the time, once two populations/organisms have stopped exchanging DNA, they become incompatible and cannot start exchanging DNA again
Why is Omran's concept of the earliest stage of epidemiology as one of pestilence and famine not necessarily correct?
Because prior to agriculture in the last 10,000 years, low-density hunter gatherer life included few famines, balanced nutrition, long inter-birth intervals, lower threats of widespread epidemics
Why is the name SIV a misnomer?
Because the virus doesn't cause immunodeficient in most non-human primates
Why is it impossible to rid the world of influenza A virus?
Because there is a huge and diverse reservoir of influenza viruses in wild water birds.
Why were bacteria and protozoa discovered long before viruses?
Because viruses are sub-cellular parasites that cannot be seen by light microscopy.
Why is it impossible to place viruses on the tree of life?
Because viruses do not contain any DNA that can be directly compared to the DNA in cellular life forms
How can liquid blood rapidly form a clot?
Blood is super charged with proteins that can react to contact with oxygen and form mesh works of fibers that can crosslink and entrap platelets, thus forming a clot.
Which mechanism is more important in the somatic evolution of B and T cells, negative selection, or positive selection?
Both are equally important
Name 2 ways in which biological and cultural inheritance are similar and two ways in which they differ
Both types of inheritance represent transmission of information, both are affected by change over time; cultural inheritance doesn't include the inheritance of genetic information and it can spread horizontally or even from younger to older generations
How can scientists get information about the Neanderthal microbiome?
By extracting ancient DNA from dental calculus of Neanderthal fossils as old as 40,000 years.
How could a protein guard the genome?
By stabilizing DNA during replication and/or recruiting DNA repair mechanisms
How can scientists test the effect of a genetic mutation involved in immune cell activation against the plague?
By testing immune cells with different genotypes with regard to their activation to plague bacteria in a dish in the lab
How does the macrophage recognize the bacteria?
By using innate immune receptors that recognize pathogens associated with molecular patterns (PAMPs).
Give an example of a disease which was established relatively recently?
Cannabis use disorder, gaming disorder
What factor could cause very closely related species such as humans and chimpanzees to have very different susceptibility to infection by a given virus?
Changes in nature and/or distribution of cell surface molecules (proteins, glycans, or lipids)
What are post translational modifications?
Changes to protein molecules after these have been synthesized (translated from mRNA)
Give 4 characteristics of the genome that can affect gene expression
Chromatin remodeling, histone modification, DNA methylation, non-coding and microRNA (+RNA binding proteins, DNA binding proteins = transcription factors)
Which factors helped spark the HIV/AIDs pandemic?
Colonialism, mass migration, urban centers including sex workers, intercontinental medical aid, blood commerce, sex tourism, IV drug use
What is the effect of multiple infections on pathogen virulence?
Competition between co-infecting pathogens can increase virulence of each.
What are 3 reasons that mammals are especially prone to cancers?
Complex multicellularity, placental, long-lived
What epigenetic modifications could influence cancer risk?
DNA methylation, histone modifications, non-coding RNA
How does the adaptive immune system prevent cells from reacting against self?
Developing immune cells that recognize themselves too strongly are forced to undergo apoptosis (controlled cell death).
What is aneuploidy?
Deviation from normal chromosome numbers
Name 3 important behavioral factors that strongly affect cancer risk
Diet, tobacco use, and UV exposure
What would a larger number of prey animals contribute to changed pathogen load?
Each species carries its own collection of microbes, by handling the carcasses of more different species, human ancestors would have samples larger number of pathogens
List for areas where the human footprint is particularly measurable on the planet
East Asia, South Asia, Europe, and Eastern North America
How is infection by an enveloped virus like a nano-transplantation?
Enveloped viruses are wrapped (enveloped) in the cell membrane of the host in which they were produced. In a new host, this can make them antigenic.
What does the queen bee have to do with epigenetics?
Enzymes acting on histone modifications in the royal jelly produced by worker bees and fed to the developing queen larva causes the same egg to become a queen rather than a worker.
What are carcinomas, sarcomas, and leukemia cancers?
Epithelial, muscle or blood cancers
What novel risk did agriculture bring for people?
Famine, warfare, taxation, social inequality
What was the contrast in animal domestication between the Old World (Asia and Europe) and the New World (Americas)
Far fewer animals species domesticated in the New World; dogs arrive with first waves from Asia, turkey and llama/alpaca, and guinea pig
How might regular use and fire and tuberculosis be related?
Fire brings people together and damages lungs
What is the evidence that our ancestors were upright by over 5 million years ago?
Fossil skeleton of ape-like species with skeletal adaptation to upright posture (foramen magnum, pelvic and leg bones)
How many protein chains make up a single antibody?
Four, two light and two heavy chains
Give 3 examples of chromosomal changes during evolution
Fusion, inversion, reciprocal translocation
How can different parts of the genome have different histories?
Genetic recombination breaks apart and brings together different parts of the genome. The further apart on a chromosome two segments of DNA are, the likelier that these do not share the same precise history
How could there be an "arms race" between selfish DNA and our genomes?
Genomes have to evolve defenses against rampant and disruptive transposon activity, but successful transposons evolve ways around these defenses
Give an example of a domesticated endogenous retrovirus
HERV9 in Tp63 in spermatogenesis, Syncytin 1 and 2 in trophoblast/placenta
What is the difference between MHC and HLA?
HLA is the human MHC
Do Japanese Hawaiians have cancer rates more similar to Hawaiians or to Japanese in Japan?
Hawaiians
What do the letter H and N in the names of different influenza A viruses stand for?
Hemagglutinin for binding to cells and Neuraminidase for cutting off sialic acid from cells or muffins
How could larger cities have contributed to the disease burden?
High density of people, better for spread of infectious disease likely to cause more social stress; Water supply very prone to getting infected; Cities rely on trade, trade can bring disease
What does chromatin consist of?
Histone and non-histone proteins and DNA
How can the chemical modification of histone proteins influence gene activity?
Histone modifications can change the accessibility of gene expression machinery to DNA
Give an example of a disease which was abolished relatively recently
Homosexuality, hysteria
How could the number of menstrual cycles be affecting female cancer risk?
Hormonal fluctuation and resulting tissue remodeling in the bread and uterus associated with each cycle introduce an opportunity for cancer causing mutations to occur.
What is the size of a human cell, a bacterium, and that of a virus?
Human cell (30mm), bacterium (~3mm), virus (~100 nm)
What are the major differences between the birth process in humans and the related great apes?
Human have much higher variation in gestation time, much longer duration of labor, and birth is associated with much higher levels of pain.
Give an evolutionary explanation for disease
Hygiene hypothesis
How can a mutation caused by an Alu element in one enzyme result in an overall change of most cell surfaces?
If the enzyme is a glycan modifying enzyme, it would affect millions of glycan chains on most cells
What is the gist of the hygiene hypothesis?
Improved hygiene, frequent use of antibiotics, and vaccination deprives children of contact with microbes and shifts the balance of the immune system towards become allergy prone to auto-immune reactions
List 3 types of different anti-viral vaccine with regard to how these are produced and delivered to humans
Inactivated, attenuated live, subunit, genetic, viral vector
What does convergent evolution mean?
Independent evolution leading to similar outcomes: biochem (caffeine), anatomy (spindle shaped swimmers), behavior (parental care of the young)
How does the rich diversity of alleles at many of the genes encoding innate immune receptors become apparent?
Individual humans can react very differently to the same pathogens.
What is a molecular polymorphism and give an example
Inherited molecular variation where at least 1% of the population differs from the rest (ex ABO histo-blood groups)
Give 3 cell types involved in innate immunity and 3 involved in adaptive immunity
Innate (neutrophil, macrophage, basophil), adaptive (B, T, T-helping cell)
How could Tb in pre-columbian South American skeleton be more closely related to TB in seals than other TB strains?
Intense coastal hunting for seals by paleoamericans could've exposed them to this new strain
What are 2 parallels between fetal tissues and cancerous tissues?
Invasive tissue, remodeling of the blood vessels, immune suppression
How can personal names and language affect individual behavior?
It allows for reputations as the actions of the named individual can be reported to a wide social network and affect that individual's social standing
How does human breast milk improve infant health?
It contains prebiotics that help the infant gut be colonized by the right bacteria, probiotics in the form of bacteria, and it contains material antibodies that attenuate infections in the infant, and it modulates infant immune development.
How could the use of a home base contribute to disease load?
It likely increased the chances of infection due to shared space and accumulation of bodily waste in a limited area.
How is it possible that doctors in the 1840s were not aware of bacterial infections?
It predated the notion of microbes or germs, only visible by microscopes and totally overlooked by all medical traditions
How could menopause be thought of as an adaptation rather than a disease?
Long post reproductive survival in female humans may be an adaptation to the importance of cultural transmission and the human reproductive pattern
Why is cancer not really a single disease?
Many different causes, different cancers have different properties and vary in how rapidly they cause death
How does meiosis differ from regular cell division?
Meiosis or reduction division, involves not just the doubling of DNA, but also the recombination
How could human hosts benefit from genes in the genome of their microbiome?
Microbial enzymes can digest food and generate vitamins
What is cephalon-pelvic disproportion?
Mismatch between head size of the baby and hip size of the mother
What 2 different parts of our genomes do not get reshuffled but are rather inherited from one parent only?
Mitochondrial DNA and most of the Y-chromosome
What technology has made the discovery of new viruses much easier?
Molecular detection (PCR, next generation sequencing, allowing the detection of viruses in primary samples without prior culture to amplify virus numbers)
What kind of information does the immune system process?
Molecular information about self and non-self, consisting of composition and shape of molecules and the patterns they form.
What are onco-fetal antigens?
Molecules that appear commonly on fetal tissues and certain cancers
How does parental age affect the risk for genetic disease in a child?
Most mutations happen in the father and more happen the older he is
What does "secretor" mean in the context of ABo blood groups?
Most people also produce the ABO antigens (glycans) on their secretions, a minority of people only produce them within their blood vasculature (non secretors).
List four different types of host defenses
Mucus barrier, skin, antimicrobial toxins, immune cells
What is mucus made of?
Mucus is a hydrated bio gel consisting mostly of hydrated, highly glycosylated mucin glycoproteins but also salts and ant-microbiol proteins
Give a proximate mechanism for disease
Mutation in important immune genes (e.g interleukin 10 IL10)
Why is "oncogene" not a very logical term?
Natural selection would not favor genes that cause cancers. Oncogenes have other functions important to the organism, but if mutated or not regulated properly, they can cause, or contribute to cancer
What is the difference between a neoplasm (neoplasia) and cancer?
Neoplasia is uncontrolled cell growth that can be benign, cancer includes major genetic accidents and eventually metastasis (dispersal of cancer cells through the body)
How could a natural pesticide made by plants cause addiction in humans?
Nicotine hacks the brain where it interacts with special receptors. Nicotine use rapidly creates addiction as the brain habituates to this effect and starts feeling bad if nicotine is not provided
Is infection by the plague strictly transmitted by fleas?
No the plague can become pneumonic, transmitted directly from one human to the next (airborne)
Is the human body a perfect clone of the fertilized egg cell?
No, certain tissues have somatic mutations (often associated with transposable elements), especially neurons
Are most mutations dangerous to the survival of the individual in which they occur?
No, most mutation appear to be neutral
List 2 military technologies that have caused long term health sequelae in civilian populations
Nuclear bombs and defoliating agents (dioxin)
What are the four major classes of biomolecules?
Nucleic acids, proteins, lipids and glycans
How do logging roads contribute to increased contact between human and wildlife?
Once in place, local humans who often are desperate to find new livelihoods follow these new road and establish camps along them and then hunt for animal proteins in areas that had very little human wildlife contact
How many times smaller than you is an average bacterium?
One million times
What is antagonistic pleiotropy?
Opposite effects of the same gene early and late in life
What type of multicellular animals seem to be free from cancer?
Organisms with simple or aggregative multicellularity (eg sponges)
Why is schistosomiasis widespread in East Asia?
Paddy rice agriculture forces farmers into long hours of work standing in water.
What four very different perspectives on disease can be considered?
Patient, doctor/care provider, evolving pathogen, evolving host
How does malaria parasite manipulate mosquito behavior in its favor?
Plasmodium causes mosquitoes to take blood meals from more different hosts, increasing the rate of infection of humans by a single mosquito
Farming made many new human endeavors possible, but it also ushered in or amplified the 7 Ps. List the 7 Ps
Poverty, poor health, plunder, politics, power differentials, pathogens, parasites
What are the 5 foundations of multicellularity?
Proliferation inhibition, controlled cell death, extracellular environment, division of labor, resource allocation
What is an important trade-off faced by cancerous cells?
Proliferation via rapid cell division, versus migration and mobility to invade the body.
List 5 ways in which fire massively changed the opportunities of humans before agriculture.
Protection from predators, cooking, lighting, changing landscapes, harvesting honey
What are innate immune receptors?
Proteins made by a host organism (germ line encoded, even in absence of immunization) that recognize molecular patterns on potential pathogens and parasites.
List two cell types in the body that lose their genomes as they mature
RBC, platelets, lens cells of the eye
How could shipments of car tires affect global disease?
Rain water in old car tires allow mosquitoes to breed and provide unintended transport of novel mosquito species across continents.
What two key features allow most pathogens to evolve more rapidly than their hosts?
Rapid generation time and high mutation rates
How could trade have affected the history of human diseases?
Repeated long-distance contacts and exchanges could have spread infectious diseases.
Give two examples of RNA that is functional despite the fact that it does not code for a protein
Ribosomal RNA is part of the RNA translating machinery of a cell, micro RNA takes on a 3D fold and can interact with proteins to modify gene expression.
What is the ratio of human to microbial cells in and on your body?
Roughly 1 to 1
What is the pathogen that causes malaria?
Several species of the protozoan called Plasmodium
How could a bacterial infection transmitted by skin contact in South America have evolved into a STI like syphilis?
Sexual exploitation and violence at the bends of the Spanish conquistadores could have selected for secually transmitted variants that benefit from lesions on genitals for transmission.
What is the two-fold cost of sex?
Sexually reproducing populations require twice as many individuals for the same number of reproductive events.
What could be the advantage of our genomes having multiple versions (copies) copies of the same gene (e,g hemoglobin)?
Slightly different variants of the same gene can be used at different times during development and life (embryonic, fetal, adult)
What is meant by the double burden of disease?
Societies where both, communicable (infectious) disease and disease caused by modern lifestyle co occur.
Give 2 examples each of solid tumors and liquid tumors?
Solid (carcinoma and sarcoma), liquid (leukemia and lymphoma)
What is the difference between somatic cells and germ cells?
Somatic cells are the majority of the cells in the body, germ cells are the ones that can give rise to gametes
How could transposable elements affect ape evolution?
TE, such as LAVA TE in gibbons, causes massive chromosome rearrangements. This can potentially cause reproductive incompatibility and with it speciation
Give an example of improved technology that causes diseases.
Tampons with extremely good absorbance and toxic shock syndrome
What is the pathogen that causes HIV/AIDS?
The HIV virus, a lentivirus belonging to the group of retroviruses
What is the pathogen that causes tuberculosis?
The bacterium Mycobacterium tuberculosis
What is the evidence that human breast milk contains brain food?
The brains of breast fed babies differ biochemically from those of formula fed babies.
What prevents a virus that uses Neu5Gc sialic antigen as a receptor from infecting humans?
The complete absence Neu5Gc sialic acid on humans cells
What prevents a virus that uses the alphaGal antigen as a receptor from infecting humans?
The complete absence of Alpha GaL on human cells
What is horror autotoxicus?
The horror of having one's own powerful immune system unleashed against oneself.
What is meant by the environment of evolutionary adaptation EEA?
The hundreds of thousands of years that our species spent living as foraging small scale communities
What is the notion of an obstetrical dilemma?
The idea that human mothers balance the requirement of bipedality with those of birthing a super large headed baby
Why do tumors larger than a certain size require new blood vessels?
The inner part of larger tumors cannot survive without gas exchange and nutrients
What is Koch's postulate?
The notion that proof for pathogenesis by an agent requires that the microorganism must be found in abundance in all organisms suffering from the disease, but should not be found in healthy organisms. The microorganism must be isolated from a diseased organism and grown in pure culture. The cultured microorganism should cause disease when introduced into a healthy organism. The microorganism must be reisolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent.
Why do waterborne diseases tend to be rather virulent (cause very severe disease)?
The pathogen is more likely to be passed on if the patient has diarrhea and vomits, ideally near water sources; the patient doesn't need to walk around or look attractive to infect others
How could the plague be thought of as a spillover event?
The pathogen lives in wild rodents (marmots, ground squirrels) and trade with their fur led to the importation of the pathogen to trading cities around the Mediterranean
What is the neolithic?
The period encompassing the last 12,000 years since humans have become sedentary, started farming/herding and developed complex societies.
What makes pig kidneys super antigenic in a human xenotransplant recipient?
The presence of alpha Gal on all pig cells combined with his levels of pre-existing anti-alphaGal antibodies in all humans
What is the difference between Neu5Ac sialic acid found in all vertebrates and the animal Neu5Gc sialic acid lost in the human lineage?
The presence of one additional oxygen atom in the non-human Neu5Gc
What is the difference between a primary cancer cell and a metastatic cancer cell?
The primary cancer cell arises in a particular tissue, the metastatic cancer cell has migrated to other sites in the body
What is cancer immunoediting?
The process by which the body's immune system shapes cancer and leads to either elimination, equilibrium or escape
How can sex allow slower evolving hosts to survive in the face of rapidly evolving pathogens?
The shuffling of genetic material via recombination between chromosomes generates novel combinations each generation
How can mucins be resistant to digestion?
The tightly arranged glycans make it impossible for protease enzymes to digest the core protein.
What made hominins good at obtaining bone marrow from the long bones of large animals?
Their cooperation in chasing away other predators or scavengers (hyenas and lions) and their use of stone tools to get access to fresh marrow and brain tissue after breaking the bones and skulls
Why are bats so important for monitoring emerging viral diseases?
Their high mobility and resistance to viruses make them ideal reservoirs
What is the consequence of language and kinship terms for social organization?
These allow for the formation of tribes, allowing large numbers of small groups to form very large social networks that develop cultural identities
What is unusual about prion diseases?
They are caused by a mis-folded protein, not by a living, replicating organism. A misfolded protein from outside the body causes additional misfolding of the patient's own prion molecules
Why is it totally unrealistic to eradicate influenza viruses?
They have a gigantic reservoir in many species of wild water birds that migrate across the planet
What is the reason that glycans are massively involved in infection and immunity?
This class of biomolecules is abundant at the "molecular frontier"of cells and tissues.
How can different cell types be generated from the identical genome shared by all cells found in an individual?
Through differential gene expression, with different subsets of all 22,000 genes expressed to different degrees, in different combinations, and at different times
How can increasing contact with fresh water change the pathogen regime of the human population
Through increased exposure to waterborne diseases including schistosomiasis (=Bukharzuisus), guinea worm, leptospirosis, etc.
What is the difference between variolation and vaccination?
Variolation (inoculation) uses scabs from smallpox patients to immunize naive persons, while vaccination uses scabs from cows infected by cowpox to immunize against smallpox. Vaccination has since been applied to other methods of immunization
What is the difference between variolation and vaccination?
Variolation is immunization using smallpox virus, vaccination is immunization against smallpox using the related cowpox virus.
Sialic acids are exploited by many important pathogens for invasion and immune evasion. How come, vertebrate hosts did not evolve away from using sialic acids on their cells?
Vertebrates have become critically dependent on using sialic acids for development, they cannot afford to abolish these molecules
List 2 examples each of viral, bacterial, fungal, protozoan, helminth, and prion caused diseases
Viral (polio, flu), bacterial (gonorrhea and TB), fungal (candidiasis and valley fever), protozoal (malaria and sleeping sickness), helminthic (schistosomiasis and elephantiasis), prion (Kuru and Creutzfeldt Jakobs)
What is the generation time of viruses, bacteria, parasitic worms and humans respectively?
Virus (minutes), bacteria (hours), worms (weeks), humans (decades)
Can you think of an example of viral sex?
Viruses can have segmented genomes (influenza A) and co-infection of 2 different viruses can lead to recombined viral progeny.
How could a virus cause cancer?
Viruses can manipulate gene expression and immortalize infected cells; viruses can cause mutations by inserting their own DNA into the host cell genome
Can a mutation in a single gene cause disease?
Yes, there are over 4000 human diseases caused by a single gene mutation
What is an endogenous retrovirus?
a retrovirus that has been incorporated in the host genome
What fraction of the human genome consists of retrotransposons?
almost half
Describe the evolutionary invention of milk
ancestral mammals evolved milk as a nutritious food for their young from modified sweat glands. They used a modified anti-bacterial enzyme to evolve a lactose synthesizing enzyme, making a sugar that's easy to share between mother and infant but difficult to steal by most other microbes.
How thick is human skin?
around 2mm
What are the three smokes?
biomass burning, tobacco, air pollution by industry and traffic
Which non-human species has been observed actively spreading fire?
black kites in Australia
What is anthracosis?
black lung diseases/soot accumulation in lungs
What are the parallels between Maillard reaction products and advanced fluctuation end products (AGE)?
both are products of reactions between sugars and proteins
Does Neuanderthal DNA in modern humans protect from or put people at higher risk for COVID?
both, depending on which chromosome the DNA is on
Name 3 social consequences of the Black death in the 14th century
breakdown of the social order, pogroms (violent upheavals) against local Jewish populations, religious upheaval (protestant reformation)
How could xenotransplantation represent health risks for the general human population?
by allowing animal viruses to infect the immune suppressed human patient, to adapt and then to infect other healthy humans
How can our genomes defend themselves against molecular parasites such as transposons
by inactivating the chromatin in which the transposons are located
Give 3 environmental causes for DNA damage
chemical substances, radiation, viruses
How could cigarette smoke harm a child before it's born?
compounds from cigarette smoke can make it into the bloodstream of the fetus and harm brain development and cause alteration of chromatin.
How have animal immune systems evolved by use of transposons?
different animal lineages have recruits transposon DNA to generate diversity used in their immune system
How are transposons involved in neuronal diversity?
during neurogenesis, transposon activity is increased, generating differences in the genomes of neighboring neurons
Why are tissues with rapidly dividing cells more prone to cancer?
each cell division requires the replication of the cell's entire genome, this is an opportunity for replication errors (aka mutations) to occur
What is evolution bricolage (Francois Jacob)?
evolutionary tinkering; novelty can be pieced together from different existing features
Give an example each of heritable and non-heritable variation
eye color (heritable), hobbies (non-heritable)
Given an example of an importance human technology that doesn't fossilize
fiber technology, ropes, strings, baskets, fabrics
How might regular use and fire and tuberculosis be related?
fire damages lungs and brings people together
Why would the activity of a transposon be dangerous for organisms in which it happens?
genomic instability/mutation/disruption of gene function
What is the difference between horizontal and vertical transmission of a pathogen?
horizontal is across a population via infection, vertical is infection from parent to offspring
What are 3 advantages of burning landscapes?
hunting is easier, and new grass attracts prey
What do some Australian aboriginal cultures believe black kites taught humans?
hunting with fire
Why would a bacterial enzyme that recognizes a certain DNA sequence be able to cut the genome of primates into thousands of chunks?
if the recognized sequence is identical to sequence of an Alu element, the enzyme would cut DNA wherever one of these thousands of transposons are in the genome
What is CAR T-cell therapy?
immune therapy against cancer, where the patient's own T-cells are harvested, transformed outside the body to express a cancer specific receptor and then rein fused into the patient to target the cancer
What happens to the glycocalyx of cancers?
it is always altered from that of healthy cells
Why do certain plants make nicotine?
it's a natural pesticide against insect herbivores
What makes a retrovirus a retrovirus?
its genome encodes an enzyme that can back-transcribe RNA into DNA
How could logging roads affect emerging diseases?
local people and immigrants use the road to access new areas where they farm and hunt for bushmeat.
Name 3 conditions that represent costly consequences of bipedalism in humans
low back pain, obstetrics, hemorrhoids
What are the demonstrated effects of micro plastics in lab mice?
lower sperm count in males and lower body weight of pups sired by these males.
Does the human genome contain more genes or more transposable elements?
more TEs
What is likely wrong about the notion of "junk DNA"?
much of the non-coding DNA seems to have functions in the genome
Give an example each of random and non-random events during biological evolution
mutation (random), survival under certain environmental conditions (non-random)
Give an example of a human disease caused by an Alu element
neurofibromatosis
Are human and chimpanzee genomes the same size?
no, chimpanzee genomes are slightly larger due to accumulated repetitive sequences
Can somatic mutation be passed onto the next generation?
no, only germ line mutations can
Are humans the only mammals species that domesticated an endogenous virus to evolve a better placenta?
no, several other mammal species have independently done so
What is especially previous about evidence for fire in caves?
one can safely rule out natural fires from lightning strikes
Name 3 ways in which industrial development can change disease burden
pollution, urbanization, social injustice
Name two chemicals not related to fire and smoke that bioaccumulate in the food chain
polychlorinated biphenyls (PCB)) and methyl mercury
What are the effects of polyaromatic hydrocarbon (PAH) on brain anatomy in humans?
reduction of brain white matter (connections between neuron)
What are the three key ingredients of biological evolution?
replicating entities, heritable variation, differential reproduction
Where can paleoclimate researchers find modified glucose from biomass fires tens of thousands of years ago?
sediment samples from ocean drill cores
How could food preparation contribute to disease risk?
smoke from indoor stoves or fireplaces and cooking, frying and baking can generate harmful toxins
What PR trick was used to widen the tobacco market after WWI?
smoking was heavily advertised to women
Name 3 cell types in mammals that have evolved to invade the body of another individual
sperm, trophoblast (extravillous), transmissible tumors in carnivores
Give an example of a domesticated virus
syncytin 1 and 2 and suppressyn on human trophoblast
Why is Rett's syndrome only observed in females
the X-linked mutation is lethal in males
Why is the genome of the pufferfish so much smaller than that of most other vertebrates?
the ancestors of the pufferfish purged transposable elements from their genome
What can honey guide genetics teach us about human fire use?
the ancient divergence between bird lineages that do or do not interact with humans, point to the deep age (~2 my) of fire use by humans
What is the difference between endocannibalism and exocannibalism?
the hundreds of thousands of years that our species spent living as foraging small scale communities
What is the origin of the word vaccination?
the latin word vacca = cow, given that cowpox was used to immunize humans against smallpox
How can mucus impact infection risk by a virus?
the mucus can contain receptor molecules for viruses and act as a decoy/smokescreen
What is the difference between Neu5Ac sialic acid found in all vertebrates and the animal Neu5Gc sialic acid lost in the human lineage?
the presence of one additional oxygen atom in the non-human Neu5Gc
What happens to the rate of evolution in small populations?
the rate gets higher, and evolution accelerates
Why are PAH mutagenic/carcinogenic?
these are multi-ringed molecules that react with DNA which can cause mutations during DNA replication
How are microbiota like micro Serengetis?
they represent complex communities of multiple species
What did the Justinian plague of the 6th century, the black plague in the 14th century, and the HongKong plague of 18902 have in common?
they were caused by the bacterium Yersinia pestis
If life expectancy is around 35 years for most hunter gatherers, how can there be substantial numbers of 70 year olds in those societies?
very high infant mortality brings down the life expectancy
List 5 major classes of human pathogens
viruses, bacteria, protozoans, helminths, fungi and prions
Do we humans have transposable elements that do not exist in apes?
yes, a subset of young Alu elements for example have only replicated and inserted after our last common ancestor with apes
What is the size of a virus?
~100 nanometers