Mammalogy Exam 3
Terms in this set (150)
Major factors contributing to emerging infectious diseases
1. Human demographics and behavior
2. Technology and Industry
3. Ecosystem alterations, climate change
4. International travel and commerce
5. Microbial evolution
6. Poor public health measures or breakdown (poverty, war, famine etc)
there are more of us, higher population densistes, facilitates spread of disease
this could be positive (vaccine development) or negative (weaponized pathogens)
this process exposes humans to new diseases or a zoonotic vector changes its distribution in response to a changing climate
International travel and commerce
spreads disease or disease vectors more easily
Microbes develop resistance to drugs, then out breaks occur (or re-occur)
What is the plant's population currently? estimate for 2050?
7.6 billion , 10 billion
What has development of human society lead to?
Unprecedented environmental changes like large scale land modification to global movement of people, animals, plants and microbes. Few ecosystems can be called remote/pristine.
What do environmental changes do to disease?
the can enhance or inhibit the development of certain diseases.
In the last two decades what has happened in regards to disease?
increase in the number of cases of a wide spectrum of diseases in populations of diverse species of plants and animals.
Traditionally how has infection disease been viewed?
A problem that is best adressed through the use of vaccines or drugs.
What are the majority of emerging diseases?
Zoonotic (Lyme, AIDS, severe acute respiratory syndrome SARS, avian influenza, West Nile virus, hantavirus, monkey pox, Lassa fever, etc.) first arise in animal sna dpeople eventually become victims as well. Therefore, there is an increased need to study disease dynamics in those animal populations (reservoir).
What do scientists now advocate for emerging diseases?
incorporating ecological methods into traditional epidemiological studies of disease. These emerging diseases are not new to science but are presenting greater risks to humans.
- viral disease affects the CNS
- any mammal can get it (there are taxon-specific strains like bat rabies)
- animals become aggressive, disoriented, transmission via bites (in the saliva), may be aerosols in bat urine, scratches can also transmit.
-organ transplant transmission.
Epidemiology - Rabies
dog most frequent vector
other reserviors include:
found in most continental countries but not in some island nations.
What does the rabies virus attack
binds to nerve or muscle cells at site of inoculation at the nicotinic actylcholine receptors. Can stay here for months, can replicate in muscle cells (incubation phase)
Virus moves along nerve axons to the CNS, infection of the brain -> encephalitis and nural degeneration. From here can spread to other areas of the body (skin, adrenals, kidneys, salivary glands.)
Onset of rabies symptoms depends on what three things?
number of virus particles in infection, proximity to the brain, immunological status of the patient.
pain/itch at the wound, fever, headace, gastrointestinal problems. After two weeks CNS infection is apparent. Hydrophobia occurs in 50% f victims due to pain when drinking. Seizures, ahllucinations, paralysis -> respiratory failure, comotose.
How to prevent rabies?
Vaccination (even after exposure) effective at preventing disease. Once symptomatic rabies happens death is imminent.
What is the Milwaukee protocol? Who was the first to receive it?
Place the patient in an induced coma to protect patient from their brain in hopes the immune system produces the antibodies to fight off the virus. Given drugs to suppress brain activity and antivirals. 15/100 survival rate.
In Utah what is the most prevalent reservior?
Which state has the most rabies cases?
- bacteria called Yersina pestis
- found in mammals (rodents) worldwide
-1,000-3,000 cases worldwide
-5 to 15 cases in the W US
-14% fatal (80% untreated)
-treat with antibiotics, but success rate declines if not diagnosed early
- began in 541 AD and killed 25 million
- "Black Death" 1334 75-200 million (60% of Europe's population)
- China 1860's, spread to port cities (steamships) 10 million. Determined cause and mode of transmission
What are the tree different forms of plagues?
bubonic, septicemic and penumoic. Most are bubonic, septicemic plague is rare.
Pneumoic plague is the rares and most serious form because it can be transmitted person to person by aerosolized cough drops - DEADLY
Plague doctor mask
bird-like beak, packed with sweet smells
What is bubonic plague named after? what are the symptoms?
is named after the buboes,large boils that developed within a week after an infected flea bite (associated with lymph node pain). Early symptoms are "flu-like" followed by a white tongue, slurred speech, confusion, then blackened skin/buboes
Septicemic plague symptoms
involves blood infection by Yersinia pestis
Early symptoms "flu-like" followed by abdominal pain, bleeding from orifices and under skin and then blackening and tissue death (gangrene) of extremities
Pneumoic plague symptoms
involves the lungs and can be transmitted person-to-person by aerosolized droplets. More virulent; symptoms begin within hours and include a cough with bloody spit, high fever, difficulty breathing. If not treated in 24 hours leads to death.
Public Health Measures for Plague
1. County-wide enhanced surveillance
2. Rapid investigation of potential new cases, sample collection, testing
3. Isolation + treatment
4. treatment of all contacts with anitbiotics
5. Rodent and other vector control/testing
6. Raising public awareness about infection spread and control
Plague in the United States
-Plague was first introduced into the United States in the early 1900's by rats on steamships; mostly from Asia
-The last urban plague epidemic in the US was in Los Angeles (1924-1925)
-Plague bacterium transferred to native rodents, primarily in the western US (mostly in prairie dogs)
Plague Ecology in the United States
Plague occurs in semi-arid grasslands/scrub woodlands in the four corners area. It is transmitted by fleas and cycles naturally in the rodent population (rock squirrels, ground squirrels, prairie dogs and wood rats). If the infection in rodents increase it causes an outbreak (epizootic). Epizootics is the SW US are during cooler summers followed by wet winters. Fleas find other hosts and are transferred to humans via touching infected dead rodents or from house pets. Cats become very ill dogs just bring in the fleas.
Phylogenetic tree of monkeys and humans
Also refer to the tree in the word document, know where gibbons and rhesus macaque fall.
Summary of the ape phylogenetic tree
Lineage that gave rise to humans is about 5 million years old (woodland bipedal apes) "Pan prior"
Shift to Savannah habitat increase in meat-eating, larger brains.
Neoteny (juvenile-like) human skull
-growth of chimpanzee and human are plotted on transformed coordinates, which show the relative displacement of each quadrant.
-juvenile skulls are similar, but the adult chimps skull is much more deformed than the adult human skull which retains a much more juvenile morphology (except the relatively large chin)
What are the differences in pelvic and femur structure in chimps, Australopithicus, and humans?
The pelvis differences in chimps and the two homonid species is the humans is more bowl like in shape. The bones are more rounded, short and stout vs long and tall. For the femurs the ball and joint is directly inline with the inside of the knee joint where as the Australopithicus and humans have their femur tilted out and the ball and joint lines up with the outside of the knee joint. Other points include the teeth are in a rectangular shape for chimps and rounded for humans. The foreman magnum is also moving in a more central location in the base of the skull to support increased bipedialism.
3-3.9 mya, remains found along East Africa's northern rift valley. Fragments of more than 300 individuals have been discovered, including a nearly complete skeleton (Lucy).
known from transvaal region of S. Africa and are 2-3mya. Many features of the cranium more human like. More globular cranium and slightly higher ration of brain size to body size. Sexually dimorphic.
earliest in the genus Homo. 2.2-1.6 mya in E. Africa. Clear trend toward larger brain size. 30% larger than A. africanus. First tools.
0.3-1.8 mya. Best preserved early male cranium. They found a skeleton of 8-10 year old male (based on tooth eruption and eyebrown/pelvic morphology). Teeth are unworn and he was 5' tall at death. May have gotten up to 6' at maturity. Resembles very robust modern human from neck down.Had tools (Peking Man) dated .78 mya. Earliest representatives found in Africa, but migrated 1 mya with tools and remains found in Europe/Asia.
Skeletal remains from the Liang Bua cave on the Indonesian islands of Flores. Represented by a small-bodied, small brained adult female who lived ca. 18000 years ago, plus 8 other skeletal remains. Males are also about as small. skull is small and typical for chimps.
Skeletal remains from the Rising Star Cave, S. Africa. More than 1,500 pieces of bone from 15 individuals - infants to adults. Medium bodies and small brained (smaller than any other Homo sp.). General skull shape is homo like. Palm wrist and thumb suggest tool use. Leg bones long and slender suggest bipedal like gait. Except for slightly curved toes feet are the same. Shoulders oriented to facilitate climbing/hanging. Hip bones flare outward (ancestral trait). Long curved fingers (climbing in trees).
Europe 600-350 thousand ya. Most recent 24 -32 thousand ya. Stronger more robust skeletons, show evidence of trauma fractures which were debilitating but the individuals must have been nurtured.
How genetically diverse are humans compared to great apes? (mtDNA)
humans - 6%
E. chimps - 9%
C. chimps - 11%
W. chimps - 16%
bonobos - 11%
All of our closest living relatives harbor more genetic variation than do humans, why?
Hypothesized population bottleneck sometime in the past 60,000 years or so.
What does the hypothesized family tree of modern humans tell us?
that genomic evidence indicates that after humans left Africa, there was interbreeding between humans and Neanderthals. Later, there also was interbreeding between modern humans (who carried some Neanderthal DNA as well) and Denisovans in Asia. After leaving Africa, modern humans hybridized with Neanderthals in the Middle East, then hybridized with a second hominid species (Denisovans) in Asia. Consistent with this hypothesis is the total lack of either Neanderthal or Denisovan genotypes in sub-Sahara Africa.
Misconceptions about race
1 - human beings naturally divide into a small number of distinct races
2 - races have certain inherent strengths and weaknesses, particularly in terms of intelligence, morality and character
misconceptions are substantiated by political and ideological perspectives/lack of grounding in human cultural history.
The amount of genetic variation between different groups of humans is low.
Phenotypic characteristics do NOT map consistently to genetic profiles. One can predict with high accuracy the continental origin of humans.
What is the imporatant part about race?
We use external, phenotype traits to assign "racial" identities. However, those traits comprise only a very minuscule fraction of the human genome.
What is GABI
The Great American Biotic Interchange
What connects the North American and South American continents?
Isthmus of Panama
When did N and S America connect?
3 mya (some dispersal through island hopping)
How do we know that some mammals entered S. America prior to the formation of the land bridge?
We infer movement by estimating divergence times within a mammalian group that are now endemic to S. America. If the within group divergence time is greater than the land bridge that shows the ancestral species of that group dispersed to S. A. earlier than the land bridge formed.
What other geographic feature on S. A. was happening 3 mya besides the land bridge?
Andes Mountains final uplift that doubled their height (2000 -> 4000m). This lead to climatic changes in S. America when faunal exchanges were occurring.
How many families of land mammals on each continent before the GABI?
How many mammal families dispersed during the GABI?
Of the NA mammals how many genera dispersed south and when?
26 genera, late Pliocene/Early Pleistocene (2.5 mya)
How many S. America genera dispersed northward?
Even thought the percentages of dispersing mammals was similar for the two continents, which side did better in their migration (evolutionarily)?
N. American did better in S. America than the S. American counterparts did in N. America
In South America, how many land mammal genera are descended from N. American immigrants?
In North America, how many land mammal genera are descended from S. American immigrants?
Why was their greater success of the immigrants from N. America?
One hypothesis was climate. Any species that reached Panama from either direction had to be able to tolerate tropical conditions. Those migrating southward would then be able to occupy much of South America without encountering climates that were different. However, northward migrants would soon have encountered drier and/or cooler conditions as they moved north.
Besides climate, why was their greater success of the immigrants from N. America? (2 reasons)
1. It was also hypothesized that the North American mammals may have been shaped by millions of years of competition between mammal groups in the Northern Hemisphere, while South American mammals had been "protected" in a relatively isolated environment.
2. body size also may have been a factor. Larger species are more likely to go extinct, and South American species, in general, were larger than North American ones.
How many species of endemic S. American ungulates went extinct and why?
All 13 species, it is hypothesized that they were unable to cope with North American carnivores or with competition from North American ungulates.
What is one interesting result of the GABI? (tapirs and llamas)
Tapirs and llamas originally dispersed from North America. They later became extinct here, but survived in South America.
Today, both these groups have a disjunct distribution in which their surviving relatives are found in Asia.
Family Bunyaviridae (RNA viruses)
Genus Hantavirus is the only group in the family that is not transmitted by insects
Hantaviruses are a type of hemorrhagic fever transmitted by murid rodents (family Cricetidae and Muridae)
Viral haemorrhagic fevers occur with fever and bleeding (obviously). Signs and symptoms typically include flushing of the face and chest, small red or purple spots, bleeding, swelling caused by "leaky" capillaries, and low blood. Severe weakness, muscle pain, headache, vomiting, and diarrhea may also be symptoms. The severity of symptoms varies with the type of virus.
disease noticed during the Korean War (1950's) when thousands died from it.
Milder form in Russia/Eastern Europe (1% case fatality, high case number, cased by Pummala and Microtus is the natural host).
Seoul and Hantaan viruses was orginal to Apodemus voles but now hosted by Rattus 5-15% case mortality.
Prior to 1993 one in Asia/europe, May/June 1993 CDC combating in the four corners.
Four Corners Hantavirus outbreak. What is meant by cross reactivity being strongest?
June 1993: Sera from patients with disease cross reacted with Hantaan, Seoul, and Puumala viruses, but cross reactivity was strongest with Puumala
Rodents were trapped in and around buildings where people became infected and the deer mouse (Peromyscus maniculatus) was identified as the main rodent reservoir.
We now know that this virus has been causing disease in humans for a long time (oldest tissue sample was from a 38 year-old Utah man who died of a form of pneumonia in 1959.
In immunology, the cross-reactivity has a more narrow meaning of the reaction between an antibody and an antigen that differs from the immunogen.
brick/oval shaped viruses with large double stranded DNA genomes.
Result in lesions,skin nodules, disseminated rash
Infection due to contact with animals, people, materials
Smallpox isn't in nature but other poxviruses cause disease.
human disease for milennia.
300-500 million deaths during 20th century.
Last outbreak in 1949.
Mass vaccination then target vaccination with surveillance eliminated smallpox in 1977.
WHO eradicated in 1980.
Vaccine no longer administered.
Distinguish between a natural host (reservoir) and a host
Natural host is the long-term host for a pathogen and very likely evolved with the pathogen, whereas a pathogen can also survive and replicate in other host species.
Monkypox introduced to the US in 2003 (was the first documented human infection in the Western Hemisphere)
On April 9, 2003, a shipment of 812 rodents from Ghana, including Giant pouched rats, was received by a Texas animal distributor.
Twelve days later, an Illinois vendor received the animals from the Texas distributor. An infected pouched rat was housed with prairie dogs that this vendor later distributed to six different states in the US. These animals were the source of this outbreak, because infected people became sick after contact with pet prairie dogs.
72 reported cases, 37 were laboratory confirmed as human monkeypox, 18 patients were hospitalized. Only two patients (both children) had serious clinical illness; both fully recovered
All pets (pouched rats and prairie dogs) were incinerated and development of a new pathogen to the US was avoided.
Ecologcial niche modeling
takes known records (museum specimens) and models climate data for those sites to predict range introduced to a new area
order rodentia facts
3,100+ extant species placed in 30 families. They account for 40% of mammalian biodiversity. Range in size from 5g to 75g. Everywhere except in Antarctica, New Zealand, and some oceanic islands. INCREDIBLY diverse. (canopy of rainforest, beneath the ground, aquatic, omnivorous to specialized eating).
->Their dentition is highly specialized for gnawing (single pair of upper/lower incisors, diastema, molar/premolas; no canines; incisors are rootless and grow continuously, their anterior and lateral surface covered with enamel but the posterior surface is not; during gnawing the incisors wear like beaver teeth)
->rodents have an elongate fossa where upper and lower jaws articulate (allows lower jaw to move forward/backward and side to side to facilitate gnawing/clipping/chiseling)
->complete zygomatic arch with the mid portion spanned by the jugal bone
->feed primitively 5-toed (pollex often very small)
-> plantigrade (digest 2-5 with claws, pollex and hallux sometimes with a nail)
->baculum present, testes either inguinal/scrotal
->relatively short gestation (21-28 days), litter size typically 3-6 individuals, offspring reach reproductive maturity in about 7 weeks
Order Rodentia - Fossils
-Earliest rodents (65 mya) resembled squirrels (sciuromorphous)
-by eocene epoch, beavers and squirrels appeared in fossil record. From Laurasia. Myomorphous rodents appeared in the eocene deposits
- species colonized Africa leads to hystricongnathus rodents
-Rodents appeared in S America via Africa
- Miocene (Africa was connected Asia) allowing rodents like porcupines (hystrocognathous) to spread into Eurasia.
-During Pliocene, rodent fossils appeared in Australia. Native rodents that dominate the mammalian fauna (25% of mammals on that continent)
Giant Rodents -fossils
Giant beavers were large, lived in N.A. and went extinct, giant hutias are an extinct group of known from fossils in the west indies, thought to be as large as a blacck bear. Still smaller than the largest rodent discovered that aboriginals used for food. 10 extant species inhabit the Caribbean (another 10 are exinct)
What is the largest rodent fossil discovered?
Phoberomys pattersoni, found in lush marshes in venezuela 6mya (upper Miocene). Size of buffalo - 9' long 4.2' tall and 700kg. it as a vegetarian and forage near water. Large tail that allowed it to balance on its hind legs to watch for predators. Predators are crocodiles, marsupial cats, flesh-eating birds. Hypothesized to have become extinct when N. and S. America land bridge formed allowing new predators into S. America.
Rodent skull types
skull types are based on origin and insertion of lower jaw musculature and on the morphology of the zygomatic arch/infraorbital foramen.
4 skull types include: protogomorphous, sciuromorphous, Myomorphous, Hystricomorphous.
only one living family - aplodontidae
Sciuromorphous skull type
Families include Castoridae, Geomyidae, Heteromyidae, Sciuridae
Myomorphous skull type
Families include Cricetidae, Muridae, Dipodidae
Hystricomorphous skull type
Families include Erethizontidae
similar morphology but different genealogy
- desert adaptions (Jerboas and Kangaroo rats), jumping saltatory locomotion, have large hindfeet/limbs, long tail, fused cervical vertebrae
- fossorial adaptions (tuco-tucos and pocket gophers), burrowing with a fusiform body, small eyes and ears, large front feet.
1100 species in 250 genera in 15 subfamilies, tremendous variation in cranial and dental morphology,
Family Cricetidae, Subfamily Ichthyomyinae
Semi-aquatic, fish, crab-eating mice, 1 genus, 5 species, Southern Mexico to S. America, moderate to high elevation streams
5 genera and 12 species are strictly fossorial. Found in Africa and Middle East. Solitary to colonial. Naked mole rates are eusoical and will die if isolated from colony mates
individual contributes more to future generations by helping a mother to produce more offspring than producing themselves. There is a caste of non-reproductive workers to help the mother produce. Known as kin selection.
Three characteristics of eusociality
1. cooperation in care of young
2. reproductive casts, with non -reproductive members caring for reproductive nest mates
3. overlap among generations such that offspring assist parents in raising siblings.
Eusociality in naked mole rats
occur in dry habitats, feed exclusively on underground tubers/roots distributed patchily, each mole rat colony actively defends its burrow system against predators or other mole rats, odors distingusih foreign naked mole rats from colony mates by rolling around in the colony's feces.
- there are three casts and the queen, colonies average 75. One cast is one to three males, next cast high status breeders are workers and soldiers, smallest cast feeds the young once they are weaned and keep them warm
How does the queen in a litter work?
rules by dominant behavior and pheromone secreated in her urine that inhibit reproduction in other workers. When she dies the females fight it out. able to breed at 1 year only a small ercentage of the colony actually reproduces. Gestation is 70 days, litter is 3-12 pups sometimes 25. can live more than 27 years in captivity. Queen is the largest, increases in length for nursing/offspring by increasing cartilage between vertebrae. Queen nurses for one month, then they are fed feces until they are old enough to eat solids.
Hypothesis for evolution of eusocial behavior
-Ecological (food resources scarce and unevenly distributed/difficult to obtain; relatively low reproductive success of solitary species; predation pressure relatively heavy)
-Behavioral (parental care may have "predisposed" mole rates to cooperative breeding)
-Genetics (physical isolation of mole rats and associated inbreeding may have promoted helping behavior; cost of leaving the group (predation) may be high compared to benefits of group living)
What are the symptoms of category 4 pathogens?
all cause hypotension, shock, bleeding, neurologic symptoms; if disease progresses to multisystem failure it is usually fatal.
Why are they listed as category 4?
Because they are labeled a biosafety level 4 by the CDC
What is the difference between mortality and morbidity?
Mortality is what causes death, morbidity is being diseased.
How many cases of Lassa fever in Africa per year? fatalites?
2-3 million infections/year, 0.5 million cases/year
Why is there a higher death rate in hospitals than communities?
By the time you make it to the hospital you are mostly likely past treatment.
Where is lassa fever most common?
far west Africa, especially Sierra Leone, but also in Nigeria further to the east. Highest incidence in Nigeria, Sierra Leone, Liberia, and Guinea.
Lassa fever facts
Diagnosis of Lassa fever is difficult. Treatment includes intraveneous ribavirin, most effective early in disease when symptoms are nonspecific. Vaccine is none, primary reservoir is the rodent genus Mastomys.
Lassa fever - mode of transmission
Human infection typically occurs by exposure to rodent urine or feces through respiratory or gastrointestinal tracts, inhalation of virus, LASV is spread between humans via contact with the blood, urine or feces, or other body fluids of an infected person.
Multimammate rat, typically found in association with human habitation, capable of population explosions (females reproduce at three months, gestation is less than one month, females capable of breeding 1-5 days postpartum, average litter size >10), reproduction mainly in rainy season, but can occur year round
What does peri-domestic mean?
lives in and around disturbed human habitats. Found with humans.
What is seroprevalence?
the level of a pathogen in a population, as measured in blood serum.
What are the methods to study Lassa fever in villages?
survey households (house construction, food storage practices, rodent control practices, knowledge of Lassa fever)
sample for rodents at each house and surrounding habitat
trap for five nights
Food storage in villages
food stored in 99% of houses, rodent proof storages containers were non-existent
What was the most prevalent form of home construction
Metal with mud and stick walls and a mud floor.
-knowledge of Lassa fever and how it is transmitted is high
-did not influence rodent control activities/rodents in the home
-did reduce rodent consumption
-mud floors had increased small mammal presence (other house construction variables not associated with rodent presence)
-rodent proof food storage/rodent control practice rare, unable to see how these factors impact M. natalensis.
What was the proportion of houses with Mastomys natalensis? What percentage of Mastomys natalensis were seropositive for Lassa?
32% were seropositive
Which mammalian orders are humans closest relatives?
Dermoptera, Scandentia, Primates
-came from small squirrel-like insectivores
-13 families, 60 genera, 230 species
-in late creatceous/early Eocene epoch primates in all continents (except Australia)
-wide variety of morphological types (small insectivores to apes)
-2 suborders: Strepsirhini and Haplorhini
-characters associated with arboreal lifestyle
-hand/digits specialized (increased mobility of digits, flattened nails instead of claws, hallux and sometimes pollex are opposable)
-stereoscopic (depth perception), color vision in diurnal species
-low reproduction(1-2), long parental care(5-6)
-delayed sexual maturity
-long life span
-diet vegetation, low amounts of animal matter
-mating systems variable (solitary to social groups), tend to live in social groups
-locomotion is plantigrade and pentadactyl adapted for arboreal/some terrestrial life styles
-enlarged relative brain size (elaboration of cerebral coretex - social behavior, increased vision/decreased olfaction)
-increased dependence on learned behavior.
Why is the stereoscopic vision for primates important?
Why are human's feet so different from other primates?
Primate skull morphology
full/partial postorbital bar, forward facing orbits
-snout/muzzle is reduced
-cheekteeth complex adapted for grinding (bunodont and brachyodont)
Suborder Strepsirhini (prosimian) primates
Distribution mainly restricted to Madagascar (some in Africa, SE Asia and Asia)
-Rhinarium (wet naked nose)
-most have toothcomb on lower incisors
-scent marking/vocalization for communication
-only in Madagascar and Comoros islands
-diurnal and social
-arboreal and terrestrial (ring tailed use quadrupedal walking/climbing)
-long hind limbs and long tail
-Differ from other primates: cranium elongate, smaller eyes, fox like face
Lemuridae skull picture
aye-aye, 1 species
chisel-like incisors for gnawing bark to get insects
third finger elongated to extract insects from wood
Family Daubentoniidae skull
Lorises (4 genera, 6 species)
Sub-Sahara Africa to SE Asia
Nocturnal, highly arboreal
Solitary or in pairs
tails short or absent
Suborder Haplorhini (simians or anthropoids)
Distribution: Africa, Asia, C and S America
Groups: Tarsiers, New World (Platyrrhini) and Old World (Catarrhini)
Presence of postorbital plate
-Diet change to focus on fruits and leaves rather than insects
-evolved a larger brain (larger neocortex)
Why does Haplorhini develop a larger neocortex?
Hypothesized to be linked to enhancement of visual the system followed by an increase in complex social interactions
Anthropoid visual system
Evolved new visual system
-trichromatic color vision (full range of color preception)
-might be to aid in food detection in complex forest environments
-required more neural resources for processing
-apes have a greater ability recognize faces/facial expression (results in enlargement of areas of the brain attaching emotion to visual, use facial expression to communicate emotional states - critical for complex behavior)
-Social behavior both increase in visual cortex of brain but also in overall size of neocortex and brain.
Indonesia, Malaysia, Philippines
1 genus, 5 species
Vocalize with ultra sound
Large head with super huge eyes
elongate tarsal bones (jump/grasping)
New World Monkeys (Platyrrhines)
C and S America
flat nosed (platyrrhine)
nostrils are far apart and open to the side
some species with prehensile tails
1 genera, 58 species
-live in troops or families
-arboreal (rainforests, deciduous and montane forests)
leaping hopping and quadrupedal
Marmosets and tamarians
5 genera, 26 species
C and S America
No sexual dimorphism
Nocturnal, highly arboreal
extended fam groups
insects, fruit tree resin diet
quadrupedal locomotion, able to leap and hop.
Old World Monkeys (Catarrhini)
Africa Malaysia, southern Asia
Very diverse morphologically/ecologically
downward facing nose (catarrhine)
nostrils close together and open downward/forward
two premolars, premolar in mandible is sectorial (specialized for sharpening the upper canine), molars have sharply connected cusps
no prehensile tails.
40% of all primates (18 genera, 81 species)
baboons, macaques, mandrills, proboscis
large canines, powerful jaws, sexually dimorphic
quadrupedal, some terrestrial
What are the trends in relative limb size from gibbions to humans?
the arms are as long as the body, to near the feet, to near the knees to by the hips in humans.
gibbons, 1 genus, 11 species
SE Asia tropical forests
Brachiation mode of locomotion
forelimbs longer than legs
Family Hominidae (formerly Pongidae)
Orangutans, chimps, gorillas, humans (4 genera, 5 species)
Africa, Borneo, Sumatra
fruit leaves roots insects
Types of mating systems
Monogamy, Polygamy (polygyny, polyandry), promiscuity
Sexual dimorphism and mating system in primates
Sexual dimorphism in body size, canine size is related to mating systems
Mate competition is ore intense in polygynous than monogamous systems
Size is critical in mate competition in polygynous systems
Parental care in mating systems
social relationships may form between sexual partners and they become parenting partners
-usual in monogamy
-polyandrous males and females stay together to rear young
-Polygynous male may pair with one female, others left on their own
-highly polygynous systems/promiscuous systems, parental care is rare to none.
Orangutan social organization
solitary except for mother/offspring bond. Males intolerant and establish territory to get access to females. Many females live in the territory and each has their own separate home range.
gorilla social organization
Polygyny. Single male with "harem". Strong bonds between male/females and female/offspring
Chimpanzee social organization
male/male in order to hunt and protect shared territory. Females live in overlapping home ranges but no bonds. Alpha male most reproductive opportunities.
bonobo social organization
peacefull and egalitarian. strongest female/female bonds. Male status depends on mother (close bond). Polygnous and mating enhances bonding (not just reproduction)
Human Social Organization
most diverse. male/male and female/female bonding. All systems occur but polygyny is most common.
Human mating system
variety (low body size dimorphism)
gorillas mating system
polygynous one male (high body size dimorphism)
Orangutans mating system
polygynous, solitary (high body size dimorphism)
gibbions mating system
monogamous (slight body size dimorphism)
chimps mating system
polygynous multi male (moderate)
Bonobos mating system
polygynous multi male (moderate)
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Philo 202 Study Questions
Unit 1 Midterm Philosophy 202