Flashcards
L3- Evolution Flashcards
Flashcards do conjunto (61)
- 1Typical Primate Features- large brains for body size
-forward facing eyes
reduced snouts
-reduced teeth number
-prehensile (grasping capability)
-sensitive fingers and toes (fingerprints)
-Nails instead of claws
-pentadactyl (five digits) - 2Evidence that Humans are primates-95% of DNA is common between humans and chimps
-Large brain size compared to body size - 3'if people evolved from chimpazees then why are there still chimpanzees?'Humans and Chimpanzees BOTH evolved from a common ancestor millions of years ago, hence there are still chimpanzees around today.
- 4Primate SkullCranium
Prognathism
Nuchal Crest
Diastema
Zygomatic Arch
Sagittal Crest
Foramen Magnum
Brow Ridge
Canines and large molars/ premolars - 5Zygomatic Archstrong Chewing muscles pass through the zygomatic arch in the 'cheekbone'
Muscles are attached to mandible and skull - 6Nuchal CrestExtension of the skull to which the neck muscles are attached these muscles position and move the head and cervical vertebrae
- 7Sagittal CrestRidge of bone running lengthwise along the midline of the top of the skull. Strong jaw muscles attatch.
- 8Foramen MagnumLarge hole at the base of the skull where the spinal cord goes through to the brain
- 9DiastemaGap between the teeth where the large canine teeth fit for the teeth to come together
- 10PrognathismThe protruding lower half of the face/jaw
- 11Brow RidgeBony ridges around the eyes to protect form strong forces and chewing and biting
- 12MandibleLarge and heavy Lower jaw bone in Primates
- 13Human Skullinsert
- 14BipedalismAbility to walk upright and solely on the hind legs
- 15Bipedalism- RibcageChimp Ribcage is cone shaped compared to humans which is barrel shaped
> Cone shaped chest allows a wide range of motion around the shoulder for vertical reaching.
> Barrel shape allows arms to swing freely at sides and help with upright balance for walking - 16Bipedalism- Feet> Humans toes are straighter and shorter compared to other primates
>Big toe (hallux) is aligned with other toes to provide propulsion push off from ground
>hallux is larger and robuster than other toes in bipeds
>chimps have opposable thumbs for carrying and grasping branches
>Humans have developed longitudinal arches for the foot to push off the ground with toes
>robust heel bone to absorb forces of heel strike and for stability.
>Chimps feet lack arches- whole foot touches ground - 17Bipedalism - Foramen Magnum>In humans foramen magnum is nearer the skull centre, opening directly down.
>In apes foramen magnum lies towards the skull back.
>these are because head position is different during locomotion
> Human cranium is placed directly above the vertebral column and the position of foramen magnum helps to balance the head above the spine
>Apes head project forward from spine, Foramen magnum position reflects the apes quadrupedal locomotion - 18Bipedalim- Nuchal Crest> Fewer muscles are required to hold the head up humans don't have a large nuchal crest at the back of the cranium but apes do
Cranium in apes projects forward from spine. - 19Bipedalism - Spine>Balance is critical in bipedal locomotion
> Vertebral column of humans has ...
>forward bend of lumbar
>back bend in the thoracic region
> Creates an S shape spine
> 2 curves of spine centre gravity over the pelvis and allow spine to flex absorbing walking force
>Bow shapes spine of chimps supports their abdomen and absorbs forces of quadrupedal movement. - 20Bipedalism - PelvisHuman pelvis is vertically broader shorter and curves forward for organ support whilst upright.
>Muscle attachment stabilise horizontally for smooth non swaying gait
Pelvis is bowl shaped to balance torso weight over hips
> Chimp pelvis is narrow and flat in comparison
>gluteal muscles are positioned differently - 21Bipedalism- Femurs (in humans)>for bipedalism centre of grav must be over one leg during a stride
>in humans pelvis is wide but femurs are angled so knee joints are closer to to the midline than the hips (valgus/ bicondylar angle)
>knees closer together feet directly below centre of gravity
>head of human femur is larger to increase weight transfer
>human knee joints are enlarged to support increases body weight - 22Primate Locomotion- Knuckle walkingKnuckle Walking- enlarged knuckles to allow weight to be centred over the middle segments of the fingers, allows quadrupedal movements, outer fingers don't touch the ground an therefore can carry things.
- 23Primate Locomotion- ArborealMeans they Live in Trees (niche)
- 24Primate Locomotion- BrachiatingBrachiating - Pivoting wrist joints, long forelimbs, short lumbar spine. Long curved fingers and flexible shoulder allow them to swing from branches.
- 25Bipedalism - Femur (in chimps)>Chimps femur not angles inward
>knees are separated, legs positioned direct under hips
>centre of gravity position is less important in chimps as body is supported by two or more legs for quadrupedal locomotion - 26Evolution of Bipedalism- Why did hominin's evolve to upright obligate bipeds.One theory is that our early ancestors became bipedal to free up their arms and hands for carrying of resources (food, offspring, tools ,weapons)
- 27Second theory for bipedal evolution- Environment influencesin a predominantly forest environment Arboreal lifestyle made it easy to escape terrestrial predation, travel for food m nest an find shade, etc. Brachiation was important for travel and bipedalism could be useful
When the environment became cooler and dryer, grassland and open woodland became the main environment. The travelling range for food and water was longer, objects would need to be carried, avoiding predators was more difficult in open land. Bipedal locomotion became more useful than brachiation for transport. - 28Selection for BipedalismNatural Selection cannot create bipedal behaviours, but it can act in their favour once it has developed.
- 29Benefits of Bipedalism - Thermoregulation>Subjected to less solar radiation while standing and absorb up to 60% less heat
>Less water intake is necessary to counter the heat allowing further distance travel
>When standing the Upper bodies of bipeds experience more air current to keep cool - 30Benefits of Bipedalism- Avoiding Predation>Being able to see over the tall grass to identify and avoid predators.
>Standing upright may however have made them easier to spot for predators. - 31Benefits fo Bipedalism - Energy efficiency>no faster than quadrupedal
>however may require less energy than knuckle walking
>Less expended energy foraging allows for longer better foraging journeys. - 32Benefits fo Bipedalism - Hands Free>better upright walking meant primates could forage more widely, carrying tools and weapons, and bring back food
> this increased survival of their mates and offspring,
> increasing chances that their genes would be passed onto the next generation. - 33Problems with Bipedalism>The human spine is put under a lot of stress and can cause back pain and injury
>Forces travel down to knees, ankles and feet making them too susceptible to injury
>the evolution of the pelvis for bipedalism caused the pelvis to become narrow and decreases size of the birth canal.
>development to increased intelligence developed a bigger cranium.
>this lead to 'obstetrical dilemma'
>Resulted in the human birth process being more painful, long and dangerous than in other primates. - 34Endocranial Features>Human brain is bigger than chimpanzee brain (approx. 1350 cm)
>big brain does not = more intelligent
>our brains are structurally more complex
>More surface area due to many folds and wrinkles in human brains with greater connections between the parts
>humans have larger frontal lobe giving the ability for abstract thought and logic, art ability, language imagination.
> cerebellum gives balance and coordination.
>Cerebellum is larger in humans and gives refined motor skills - 35Language and the brain- Wernicke'sGives sensory inputs and is the region responsible for language comprehension
- 36Language and the brain - Broca's areaSection of the brain which coordinates muscular movements required to produce speech.
- 37Hominidare the group made of all extinct and extant great apes (modern humans, chimps, orangutans, gorillas)
- 38Homininsub group of hominids consisting of modern humans ,extinct human species, and all immediate ancestors.
- 39Hominin Evolution
- 40Ardipithecus Ramiduswkjn
- 41Australopithecus afarensiswk kv
- 42Australopithecus africanusefiefe
- 43Paranthropus boiseiwm wk
- 44Homo Habilisv vier
- 45Homo ergasterfmmfm
- 46Homo erectusmmm
- 47Homo heidelbergensisjsdcn
- 48Homo neanderthalensismmvm
- 49Homo sapiensdndns
- 50Trends in Cranial Capacityekcmwq
- 51Homo naledisj
- 52Leaving Africasmsm
- 53Origin of modern Homo Sapienscc
- 54Mitochondrial DNAsms
- 55Genetic Diversitydmsmms
- 56Cultural Evolutionsjndqnd
- 57Stone Tool Developmentkfm
- 58Use of Fireznf
- 59Huntingjne
- 60Animal Domesticationekw
- 61—
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- NCEA Level 2 Biology FlashCards sobre L3- Evolution Flashcards , criado por Sophie Painter em 05-09-2018.
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- Sophie Painter
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