L10 - Mammals and Primates Flashcards
What are the characteristics of mammals?
Body covered in hair (insulation), mammary glands (to nourish young), teeth which are socketed (thecodont) and differentiated (heterodont). Most bones have epiphyses, diaphragm for respiration, four-chambered heart, homeotherms (ca. 37deg C).
What is the function of body hair?
Insulation, other secondary functions included camouflage, signalling/warning, sensory function.
What is the function of mammory glands?
To nourish the young, abdominal, thoracic, inguinal in pigs. Thoracic in primates.
What is the function of body teeth?
Socketed (thecodont) and differentiated (heterodont). Canines - pointed teeth, carnivores use for piercing, gripping, tearing, in herbivores they are reduced or absent. Incisors, chisel-like, used for cutting, gnawing, and grooming. Molar & premolars, crush and grind food, ridged shape of the wolf’s molar and premolar allows them to interlock during chewing, like blades or scissors. The broad, flattened molar and premolars of horses are adapted for grinding tough plants.
What do most bones have?
Epiphyses
What is the function of diaphragm?
It is used in respiration, ventilation in reptiles (all amniotes) based on aspiration pump. Intercostal muscles move ribs, altering shape of the body walls around lungs. Inhalation: ribs move out, cavity around lung enlarges, air pressure decreases in lungs. Exhalation: ribs move in, compress lungs, expel air.
How many chambers is a mammalian heart?
4 chambers.
What are the subclass Prototheria (the monotremes)?
Order monotremata (monotremes, egg-laying mammals)
What are the subclass Theria?
Infraclass Metatheria (marsupials). 7x orders. Infraclass Eutheria (placental mammals). 20x orders.
What are the subclass Prototheria, order Monotremata (monotremes)?
Egg-laying (oviparous mammals), only 3 genera in existence. Sprawling gait, not entirely homeothermic, cloaca.
What are the subclass Theria Infraclass: Metatheria (marsupials)?
250 species exist in australia, new guinea and the americas. Some have yolk-sac placenta; others absorb nutrients across the uterine wall. Young born at an early stage (i.e. short gestation). Red kangaroo (Macropus rufus), Tasmanian devil (Sarcophilus harrisii), Koala (Phascolarctos cinereus)
What are the orders of the subclass Theria Infraclass: Metatheria (marsupials)?
Didelphimorph (American opossums)
Paucituberculata (shrew opossums)
Microbiotheria (monito del monte)
Notoryctemorphia (marsupial moles)
Dasyuromorphia (marsupial carnivores)
Peramelemorphia (bandicoots and bilbies)
Diprotodontia (diprotodont marsupials.
What is the order Didelphimorphia (the opossums) & Paucituberculata (the shrew opossums) of the subclass Theria Infraclass: Metatheria (marsupials)?
Virginia opposum (Didelphis virginiana) & Dusky shrew opossum (Caenolestes fuliginosus)
What are the subclass Theria Infraclass: Theria (placentals)?
Extremely diverse group with nearly 4000 species. Bear live young, nourished before birth in the uterus through the placenta.
Rodentia (rodents)
Lagomorpha (rabbits & hares)
Eulipotypha (shrews, moles & hedgehogs) Scandentia (tree shrews)
Dermoptera (colugos)
Primates (primates)
Pholidota (pangolins)
Carnivora (canines, felines & bears)
Pinnipedia (seals)
Perissodactyla (odd-toed ungulates)
Artiodactyla (even-toed ungulates)
Chiroptera (bats)
Cetacea (whales & dolphins)
Xenarthra (anteaters & sloths)
Afrosoricida (tenrecs & golden moles) Macroscelidea (elephant shrews)
Tubulidenata (aardvarks)
Hyracoidea (hydraxes)
Sirenia (dugongs & manatees)
Proboscidea (elephants)
Species of Rodentia vs Chiroptera?
2000 vs 1200
What are the subclass Theria Infraclass: Theria (placentals), order Rodentia?
2000 species, wide distribution, single pair of incisors; masseter muscles. Yellow-necked field mouse, red squirrel, crested porcupine.
What are the subclass Theria Infraclass: Theria (placentals), order Chiroptera (bats)?
1200 species, only mammals with true flight. Mainly use echolocation, specialised feeding strategies.
No. of species of Artidactyla vs Carnivora vs Primates vs Eulipotyphyla?
210, 270, 230-270, 359
What are the subclass Theria Infraclass: Eutheria (placentals), order Carnivora?
About 270, includes dogs, cats, bears, raccoons, hyenas, and seals. Not all are carnivorous.
What are the subclass Theria Infraclass: Eutheria (placentals), order Artiodactyla (even-toed ungulates)?
220 species, includes pigs, camels, sheep, deer, giraffes, antelope. Ungulates walk on their toes. Adaptations for cursorial locomotion - long strides.
What are the subclass Theria Infraclass: Eutheria (placentals), order Artiodactyla (odd-toed ungulates)?
Only 17 species, includes horses, tapirs, rhinos. Body weight borne by large central digit.
What type of fermenter are Perissodactyla vs Artiodactyla?
Perissodactyla is hindgut fermenter, artiodactyla is ruminant.
What are the subclass Theria Infraclass: Eutheria (placentals), order Cetacea?
Whales, dolphins and porpoises. One of the most specialised mammal. Around 80 species. Hippo closest land relative. Range of sizes from 1.4m to 34m. Odontocetes and baleen whales.
What was the great american interchange?
15 million years ago - present peak 3 mya. Major paleozoogeographic event. Only the most recent such event - Cenozoic India/Eurasia event. GAI - movement of animals from N america to S america via Isthmus of Panama and vice versa.
What do humans and chimpanzees share?
A common ancestor. The primate family tree goes back at least 55 million years ago.
What is the oldest primate found?
Archicebus achilles, found in 2013, lived in what is now central china during Eocene about 55 million years ago.
What are primates characteristics?
Typically have grasping hands and feet with opposable thumbs, large brains, flatter faces, flat nails, not claws. Stereoscopic vision but limited sense of smell. Long parental care with learned behaviours. Skeletal adaptations to bipedalism. Smaller, fewer, less specialised teeth.
What are humans?
An unusual form of african ape. 1.2% genetic distance between human and chimp, 1.4 between human and gorilla. 1.2 between gorilla and chimp.
Wen did chimpanzee-human divergence occur?
4-6 million years ago.
What are the two primate groups?
Promisian & Anthropoidea
What is the primate group Prosimian?
Lemuriformes (lemurs), Lorisiformes (lorises and bush babies). Prosimains are generally small, ranging from species the size of a mouse up to those as large as a house cat. They are arboreal, have five digits on each hand and foot with either claws or nails, and are typically omnivorous. They have large, forward directed eyes specialised for night vision, hence most are nocturnal.
What is the primate group Anthropoidea?
Tarisiiformes (tarsiers), Platyrrhini (new world simians) - Cebidae (true monkeys), Callitrichidae (marmosets & tamarins). Cataarrhini (old world simians) - cercopithecoidea (OW monkeys). Hominoids (apes & humans).
What is the primate group Prosimian Lemuriformes (lemurs)?
Olfactory senses well developed, smaller brains, nocturnal, adaptations for grooming or feeding (e.g. aye-aye)
What is the primate group Prosimian Lorisiformes (lorises and galagos)?
Restricted to africa, toothcombs like lemurs, bush babies: nocturnal with large fold up ears, elongate feet for hopping. Lorises: cautious and slow, strong gripping hands.
What is the primate group Anthropoidea Tarisiiformes (tarsiers)?
Native to indonesia, lack wet snout of other prosimians, enlarged eyes and elongated legs. Majority endangered. Philippine tarsier (4 subspecies), Western tarsier (5 subspecies), Pygmy tarsier (9 species)
What is the primate group Anthropoidea Platyrrhini (new world simians) - Cebidae (true monkeys)
Five families restricted to the americas, diverged around 35mya, generally small and variable in colour and form. Wide flat noses, prehensile tails, live in social groups of up to forty individuals.
What is the primate group Anthropoidea Platyrrhini (new world simians) - Callitrichidae (marmosets & tamarins)?
Central and South America, notable for small body size. Regularly (80%) produce twins.
What is the primate group Anthropoidea Cataarrhini (old world simians) - cercopithecoidea (OW monkeys)?
Found in africa and asia. Divided into Cepithecinae (frugivores) and colobinae (folivores). Baboons are the most terrestrial monkey
What is the primate group Anthropoidea Cataarrhini (old world simians) - Hominoids (apes & humans)?
Includes great apes and humans. Apes: gibbons, orangutan, gorillas, chimpanzee/bonobo. Split from monkeys about 20-25 mya. Larger brain size to body size ratios than other primates. Mostly large, have long arms, short legs and no tail. Gorillas, chimps and humans: social behaviour, primarily terrestrial, chimps more closely related to humans than gorillas.
What are the great apes (hominoidea, hominoids)?
Gibbons, Orangutan, Gorillas, Chimpanzee/bonobo. Gibbons and siamangs show an unusual method of locomotion. This involves swinging the arms; the only ape to specialise in this form of locomotion
What are the similarities of great apes: chimpanzees to humans?
We share 98% of alleles with chimps. They make and use tools. They have sense of self awareness, omnivorous, coddle their young, breast feed. Can walk bipedally.
What are the distinctions of great apes: chimpanzees to humans?
Knuckle walking, big toe has thumb-like dexterity, 50% of the time in trees (including sleeping), thicker, denser body hair. Adults have more prominant brow ridge, snout. Greater sexual dimorphism. Live in forest, 6-8mya climate change affected the distribution of forests; replaced by savannahs. As savannahs expanded, one lineage (hominids) adapted to this new habitat, one with wide gaps between patches of resources.
What happened with Prosimians and monkeys compared to hominids?
They became rare, whereas hominids diversified in the newly forming environments and became abundant. Ape populations became reproductively isolated from each other within the various forest patches, leading to adaptive radiation and increased diversity between them and the hominids.
What are the Hominids Ardipithecus kadabba?
5.8-5.2mya, ethiopia. Close common ancestor of chimps and humans. Toe bone has features of bipedal walking. Back teeth larger than chimps; front teeth narrower - suggests diet of fibrous foods.
What are the Hominids Ardipithecus ramidus “Ardi”?
4.4mya, ethiopia. Mixture of primitive and derived traits. Pelvis indicates adaptations for tree climbing and bipedalism. Do not appear to have been knuckle-walkers or spent much time in trees as chimps.
What is the ischium bone like in quadrupeds?
Ischium bone is long, and the entire pelvis is titled toward the horizontal. Compared to humans where it is much shorter and the pelvis is horizontal.
What are the Hominids Ardipithecus afarensis, “Lucy”?
2.9-3.9mya, ethiopia, kenya, tanzania. Species survived for more than 900,000 years. Ape-like face and braincase, strong arms and curved fingers for climbing. Small canine teeth like humans and mostly bipedal.
When do scientists believe that the robust australopithecines form a separate lineage from the other australopithecines went extinct?
1mya
What are the Hominids Homo habilis?
2.4-1.4mya, Eastern and Southern Africa. Slightly larger braincase and smaller face and teeth than Australopithecus species. “habilis” = “handy man”. Represents first maker of stone tools.
What are the Hominids Homo erectus?
1.9mya - 143,000 years - Africa and Asia. Elongated legs, shorter arms - loss of tree-climbing adaptations. Expanded braincase - greater intelligence. Earliest use of fire and, possibly, rafts and dug-out canoes.
What are the Hominids Homo neanderthalensis?
400,000 - 40,000 yrs ago, Europe & Asia. Our closes extinct human relative. Used sophisticated tools, controlled fire, lived in shelters, made and wore clothing, were skilled hunters of large animals and occasionally made symbolic or ornamental objects.
What are the Hominids Homo sapiens?
Approx 100,000 yrs ago - present. Turning point about 12,000 BCE, with advent of farming and herding, and urbanisation. Human evolution has shown trend towards increased brain size. Homo sapiens interbred with at least two of the other species in the Homo genus. If you are Caucasian between 2-5% of your DNA is neanderthal. If you are melanesian between 1-5% of your DNA is Denisovan.
Only our species made it to present days, fossils show our species living alongside other hominids. What are the two theories?
Multiregional and Replacement.
What does MtDNA reveal?
Shows that we descended from a single woman 99,000 - 200,000 yrs ago, most likely east africa. Genetic and fossil evidence supports the replacement theory.
How did homo sapiens survive?
They outcompeted other hominid species we encountered in Europe and Asia. There was limited interbreeding between us and at least two of the other species in the Homo genus. All of the variation in human phenotype is recent. In 100,000yrs, we went from a savannah ape to the moon.
