modern humans Flashcards
what other homo species led straight into the homo sapiens species
homo heidelbergensis
where did the “technological colonizers” originate from
africa
were african hominins more similar to neanderthals or modern humans
modern humans
in 300 kya, when the expansion from africa was occurring, where did the neanderthals primarily end up
europe and west asia
in 300 kya, when the expansion from africa was occurring, where did the denisovans primarily end up
asia
in 300 kya, when the expansion from africa was occurring, where did the other archaic homos primarily end up
east asia and oceania
in 300 kya, when the expansion from africa was occurring, what else was expanding and evolving
the modes of tools originating expansion from africa outward
what are some derived characteristics of modern homo sapiens
- high forehead
- 1350 cc (smaller than neanderthal but bigger than other early homos)
- small face and teeth
- no prognathism but protruding chin
- less robust
- long limbs
what is the first possible homo sapien found and date found
skeleton from jebel ihroud, morocco with mode 3 tools found
- 300 kya
- very debated
what is the first conclusive homo sapien found and date found
skeleton from omo kibish, ethiopia
- 200 kya
- definitive homo sapien
what specific types of genes come from a male
Y chromosome genes
what specific types of genes come from a female
mitochondrial DNA
do homo sapiens have low or high genetic diversity
LOW GENETIC DIVERSITY
- all genes could be traced back to adam and eve theoretically
what are two reasons why homo sapiens have low genetic diversity
- evolved relatively recently (200kya)
- descended from a bottleneck population
do chimpanzees have a higher or lower genetic diversity than homo sapiens do
chimps have a higher genetic diversity
what continent is there more genetic diversity of homo sapiens than anywhere else on earth
africa
- helps explain the expansion of homo sapiens from africa theory
what is the trend between distance to africa and genetic diversity rates
the farther a population is from africa, the lower amounts of genetic diversity it has
what is the serial founder effect
this is a type of genetic drift where there is a small subset of the population that leaves its own population but they travel really far away which limits the genetic diversity in the new population
what time is it expected that the migrations out of africa happened
60kya
when is the LCA of denisovans, neanderthals, and homo sapiens dated to
700 - 500 kya
T/F samples of ancient DNA can be taken from fossils even as old as 1.6mya (mammoths time period)
TRUE
DNA degrades quickly but fragments can still be found as ancient DNA
T/F modern homo sapiens have some neanderthals ancestry still
TRUE mostly in southwest asia!
would african modern homo sapiens have some neanderthal ancestry
NO because the neanderthals were not located in africa, so just the populations that left africa would have interbred with them. so many african groups today are not neanderthal connected.
what are the two helpful genes from denisovan and neanderthal interbreeding that natural selection didnt remove
the two genes that were beneficial were:
- skin pigmentation
- high altitude hemoglobin
which populations of homo sapiens that left africa interbred with denisovans
the ones going to the pacific (southeast asia, australia, islands)
what part of the world had lots of interbreeding between denisovans, homo sapiens, and neanderthals
eurasia
how many years ago was the single wave of migration into the americas from asia
23-13 kya
what is evidence of the date at which the homo sapiens made it into the americas
21 kya dated fossil of footprints found in new mexico
- def homo sapiens bc footprints are clearly bipedal
how many years ago was the migration into the caribbean and polynesian islands
5-1 kya
what date is marked as when humans reached all over the globe
10 kya
what date did agriculture start
12 kya
what is the cultivation of plants and rearing of animals for food, textiles, and other products using new technological innovations
agriculture
what is the evolutionary process in which humans modify, either intentionally or unintentionally, the genetic makeup of plants and animals.
domestication
what was the first animal to be domesticated
dogs
- their domesticated evolution shows that they were also brought to the americas when homo sapiens first migrated
pick which of these are benefits of agriculture:
- source of food and medicine
- increased family dynamics
- better workers
- population growth
- sedentary lifestyle
- less waste
- source of food and medicine
- population growth
- sedentary lifestyle
pick which of these are disadvantages of agriculture:
- more waste
- nutritional deficiencies
- more wars over food
- pollution of land and water
- crowd diseases
- sedentary lifestyle
- cavities
- more waste
- nutritional deficiencies
- pollution of land and water
- crowd diseases
- cavities
what led to these effects:
- differential wealth
- specialization of labor
- concentration of political power
- increased social stratification and inequality
food surplus and the ability to store food
what led to a decreased diet diversity
agriculture because they focused more on eating the domesticated food instead of a diverse set of foods
T/F domesticated animals had no impact on our specializations
FALSE dogs expanded our niches by allowing us to hunt, herd, protect, transport, and have a companion
livestock provided food, farming, mobility, transport, goods
all of these are now easy
where are most differences between chimps/bonobos and homo sapiens found in the genome
in transposable elements (matching genes that have differences) of regulatory genes
what is neoteny and what species has a lot of it
retention of juvenile features (delayed maturation) in humans vs other primates
what are the two factors that influence human variation
genetics and environment
how is within a group variation caused
by the heterozygous vs homozygous alleles
how is between groups variation caused
genetic drift creates local environment adaptations
the example of sea nomads having larger spleens describes what principle and how
the sea nomads have larger spleens which hold more oxygenated red blood cells that get released into the blood stream meaning they can stay underwater and hold their breaths for longer than anyone else.
this is a local adaptation of the sea nomad population
explain how skin pigmentation is a local adaptation
because the closer you are to the equator, the more UV radiation you get from the sun
the local adaptation is that your body will produce more melanin to protect you from the higher levels of UV radiation, which in turn produces a darker skin pigmentation
why did lighter skin evolve
because they moved further from the equator, which means less UV light is reaching them, so they aren’t taking in enough UV light to produce the necessary amount of Vitamin D, so their bodies adapted to lower the amount of melanin so that the correct amount of UV could get in to produce that vitamin d
why would females be slightly lighter skinned than males
because they need to make as much vitamin d as possible when they are reproducing so their body is programmed to have less melanin
how is hair type a local adaptation
tight curly hair is the most effective protection from UV radiation so it was adapted closer to the equator
what is the name of the rule that states that there are bigger body masses in colder climates
Bergmann’s rule
what is the name of the rule that states that there are shorter limbs in colder climates
Allen’s rule
what is a local adaptation for populations that live in higher altitudes
larger lung capacity to take in more air so that they can get more oxygen in and avoid hypoxia
why are human babies born so fat
to prioritize brain growth by fueling the body which in turn makes the body bigger too
draw out the charts of what the chimpanzees vs humans calorie production curves look like
chimps males (only provide for themselves bc solitary)
_ _ _________________ _ _ _ _ _ _
___ /
chimps females (excess to provide for children and themself)
_______________
_ _ / _ _ _ _ _ _ _
___/
- chimps self sustainable at age 7
human male and female (need providing for then both provide for kids)
________
/ \
_ _ _ / _ _ _ _ \ _ _ _ _ _
\______/
- humans self sustainable at age 20
what is the hypothesis called that says an offspring would likely die if their mother dies before age 6, so the mother would ideally live long enough for them to reach reproductive maturity
the mothering hypothesis as for why mothers live past their menopause to keep their fitness going (the success of their genes being passed on)
what is the hypothesis called that says that at some point, it would be more beneficial for a mother to invest in the children of her daughter than her own
the grandmother hypothesis as for why mothers live past menopause to keep their fitness going (the success of their genes being passed on)
in what way are grandmothers important in hunter gatherer societies
in food acquisition of foraging and gathering
what animal has the grandmother hypothesis been seen to work for
killer whales when the grandchildren live longer if the grandmother is still alive
what are the traits of domestication syndrome in animals
- depigmentation (white patches)
- floppy ears
- shorter muzzles
- smaller teeth
- docility (less aggression)
- smaller brain
- more non-reproductive sex
- neotenous (juvenile) behavior as adults
- curly tails
what is Paedomorphism
juvenile traits and behaviors in domesticated animals
what was the russian fox experiment
the experiment was trying to domesticate foxes but thats not possible theyre just tame.
it bred foxes that showed the least aggression (the foxes that would let the studier get the closest to them) and this created very nonaggressive foxes just not domesticated
what is self domestication
reduced aggressive behaviors compared to ancestors without the involvement of another species
what species shows lots of evidence of self domestication and why
bonobos because they are less aggressive and have smaller brain sizes, and theres evidence that the females would retaliate against aggressive males which would select for the less aggressive behaviors to be passed on
what is evidence that humans were self domesticated
smaller cc, less prognathism, more cooperative behaviors, more non-reproductive sex, neotenous behavior (sports and play as adults)
what is the capital punishment hypothesis
explains how humans were domesticated by the capital punishment executing individuals with the most aggression, bullies, and non cooperative people
what is the name for people who gain their livelihood
fully or predominately by some combination of gathering, collecting, hunting, fishing, trapping, or scavenging the resources available in the plant and animal communities around them
hunter gatherers aka foragers
why is “man the hunter” a refuted claim
because although some of the diet consisted of meat, it primarily consisted of foraged/gathered foods most of the time
what is the difference between focal following and scan sampling in obtaining data from HG populations
focal following is following a single individual all day
scan sampling is in a specific area noting what happens there with many people that could be there
what is correlation between amount of meat eaten and the size of the territory and the altitude of the population
more meat in the diet means they need a larger territory to find the animals to hunt and its typically in higher altitudes bc the land has less edible plants
which type of HG have a lack of accumulation (private property is present but usually shared and gifted to each other)
unstratified HG
which type of HG has no formal leaders
unstratified HG
which type of HG has central place foraging
unstratified HG
which type of HG has gendered division of labor
unstratified HG
which type of HG has high mobility
unstratified HG
which type of HG has routine food sharing
unstratified HG
which type of HG has formal leaders like chiefs
stratified HG
which type of HG has religious specialists like priests
stratified HG
which type of HG had slaves
stratified HG
which type of HG has polygynous marriages
stratified HG
which type of HG had goods specialists
stratified HG
which type of HG might have mobile schools
unstratified HG
which type of HG has band level organizations within society
unstratified HG
what is band level organization in HG
a band would have a few families that are a local residential group and they may have friendship with other bands but there’s no higher level of organization like a tribe or anything like that
in unstratified HG populations, do the men or women have larger day ranges
men
-one explanation is the sexual division of labor bc they’re typically the ones who are hunting not the women
in unstratified HG populations, how would the people level status when hunting
they would credit the kill to whoever made the arrow so that there was no bragging or shame
which type of HG does not typically have a phrase for thank you
unstratified
what type of population has people who are hierarchically divided and ranked into social strata, or layers, and do not share equally in basic resources that support income, status, and power
stratified HG
which type of HG built canals
stratified HG
which type of HG had more elaborate art and language
stratified HG
what is a potlach and which type of HG had it
a ceremonial feast and giving event (as a display of wealth, some would sacrifice their slaves and other goods)
which type of HG requires rich, predictable resources that can be monopolized
stratified HG
what was the mexican poccilid fishes experiment
there were these fishes in a lake. some were asexually reproducing and others were sexually reproducing. there was a higher rate of disease in the population that was asexual (bc it just cloned genes and didn’t have any variance that might protect).
when the researcher left and came back after the drought, both populations were still there. but the sexual reproducers now had a higher disease rate which doesn’t make sense
he concluded that the sexual reproducers got so bottlenecked that they could no longer have defenses so thats why the parasites were high levels again
then he added some sexual reproducing of the same fish from another pond and came back a year later. this made the levels of parasite disease back to normal as it was before because it introduced more genetic diversity that could be used to defend against the parasites.
what is the red queen hypothesis
genetic diversity (sexual reproduction with variety) helps organisms evade fast-breeding
(and, therefore, fast evolving) parasites
what are the consequences of low genetic diversity like with inbreeding with dogs
greater morbidity and health issues
why was emotion thought to have evolved
to work as an internal motivator to get us to want our fitness to continue through our offspring
how does sexual attraction vs romantic love affect our motivation to have our fitness continue (offspring)
sexual attraction helps motivate us to try to produce genetically viable and diverse offspring
romantic love creates a pair bond so we will want to invest in the offspring
sexual attraction works on what 3 principles
not a relative
age
health
what is MPA
maternal perinatal association which means that if you witness your mother caring for a newborn, that you won’t have an attraction to them bc your brain will understand that you’re related
what is the westermarck hypothesis of co-residence
that the longer you co reside with someone, the more your brain will think you are a relative
what is the sexual imprinting time frame
for the first 6 years of your life, your brain will learn who you co-reside with and who it thinks are your relatives
what is the difference between the age preference of a mate for males vs females
males always prefer 20-25 year old women, whereas women always prefer men that are within 10 years of their age
what are some features of the face which cue attractiveness and therefore good health
symmetry
consistent color
high carotenoid content (orange complex rather than dull)
age
do similar or dissimilar MHC rates make for a better mate to produce offspring with less mutations
a dissimilar MHC is better for a better offspring
what was the tshirt test proving in terms of MHC
that the subjects tended to like the smell of the shirts of the people who had a more dissimilar MHC than them which would make them better mates
