Unit 4 AoS2 HOMININ EVOLUTION AND INTERVENTION Flashcards

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0
Q

Definition of hominins

A

Hominins refers to existing as well as extinct bipedal (erect) primates.
*Collective term for all human species and their erect (bipedal) close relatives.

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1
Q

Definition of hominids

A

Smaller subgroup of the hominoids consisting of all of the great apes (ie orangutans, gorillas, chimpanzees) and humans but not gibbons.

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2
Q

What is a primate?

A

A relatively advanced order of mammals.

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3
Q

What are some of the features that all primates have in common?

A
  • Relatively large brain for body size
  • Hands typically have five long digits with opposable thumb (on hand and/or feet)
  • Typically flat nails on end of digits
  • Typically large forward- facing eyes (stereoscopic vision)
  • Typically four upper and four lower incisors
  • Flexible arm and shoulder sockets (stemming from life in trees)
  • Tendency for erectness in stance
  • Snout is reduced
  • Reduced sense of smell
  • Relatively long gestation period
  • Parenting shown
  • Possess hair/fur and mammary glands
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4
Q

What are some features associated with bipedalism?

A
  • S-shaped spine
  • Compact pelvis
  • Change in angle of femur to tibia
  • Pelvic girdle more bowl shaped than in apes
  • Knee joint
  • Flat (arched) foot but prominent heel bone
  • Foramen magnum position is more central and at base of the skull
  • Large cerebral cortex (forebrain)
  • Large cranial capacity
  • Reduced jaw size relative to skull
  • Reduced canine and incisors (fewer, smaller teeth)
  • Nose and chin more prominent
  • Reduced brow ridge
  • Reduced body hair
  • Complex thinking and behaviour
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5
Q

What are the advantages of bipedalism?

A
  • Ability to see over the level of forest grass and other vegetation
  • Frees up hands to carry food
  • Carry offspring while attending to other tasks
  • Helped in using tools and subsequent hunting
  • Thermoregulation:less surface area presented to sun and cold; greater airflow across body when lifted off the ground
  • Efficient locomotion: low speed and longer distances
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6
Q

What is the most recent ancestor of Homo sapiens?

A

Homo heidelbergensis

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7
Q

What are ways in which the skulls from the ancestral Ardipithecus varieties to those of Homo species have evolved?

A
  • Larger and more rounded skull
  • More vertical forehead
  • Reduced brow ridge
  • More parabolic jaw shape
  • Less protruding jaw
  • Chin
  • Reduced size teeth with uniformity in size
  • No diastema
  • Foramen magnum underneath skull (at base)
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8
Q

Why are primate fossils rare?

A

Primates have rarely lived in environments suitable for fossilisation since the habitats of most primates have been tropical or sub tropical rain forests; environments in which rapid decay of dead organisms is typical.

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9
Q

What are the features of the fossil Ardipithecus?

A
  1. 8-4.4mya
    * upright stance,
    * small skull,
    * jaw similar to human
    * heavy brow ridge
    * large molars
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10
Q

Features of the fossil Australopithecus?

A

4-1.2mya

  • upright stance
  • small skull
  • jaw similar to human
  • heavy brow ridge
  • large molars
  • approx 1.5m in height
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11
Q

Features of fossil Homo habilis?

A
  1. 5-1.6mya
    * evidence of tool use
    * larger brains
    * smaller teeth
    * face less protruding
    * very similar to humans
    * brain size was approximately 500-800ml
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12
Q

Features of fossil Rudolfensis?

A
  • Along with Homo habilis, H. Rudolfensis also lived in Africa approximately 2 million years ago
  • Competitor of Homo habilis but was unsuccessful and became extinct
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13
Q

Features of fossil Homo ergaster/erectus?

A
  1. 8million-500,000 years ago
    * More modern than Homo habilis
    * Brain size of 900ml
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14
Q

Homo heidelbergensis fossil features?

A

~400,000 to 40,000 years ago in Africa, Europe and China

*Brain size 1,100-1,200ml

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15
Q

Feature of fossil Homo neanderthalensis?

A

15,000-25,000 years ago

  • Used tools
  • Keen hunter
  • Occupied European and Near East regions
  • Brain size 1400ml
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16
Q

Features of fossil Homo floresiensis?

A

The hobbit lived on the Indonesian Island of Flores only 94,000-13,000 years ago

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17
Q

What are the evidences needed in support of the Out of Africa hypothesis for the origin of modern humans?

A
  • Modern humans should appear first in Africa and only later in other parts of the world
  • Transitional forms from ancestral to modern humans should only be found in Africa
  • Variation in mtDNA should be greater in African populations than other populations
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18
Q

Evidences required in support of multiregional hypothesis?

A
  • Modern humans should appear throughout Africa, Asia and Europe during the same period
  • Transitional forms should be found in Africa, Europe and Asia
  • Variation in mtDNA should be approximately the same in human populations from all regions of the Old World.
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19
Q

What is cultural evolution?

A

*The evolution of all new characteristics, ideas, skills and customs that are not transmitted via genes but through communication, learning and symbolised behaviour.
Culture is the sum total of behaviour patterns of a social group, passed on by learning and symbolic behaviour, eg language, art, music, poetry and is not transmitted via genes but through communication.

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20
Q

Examples of cultural evolution?

A
  • Moral values
  • Foods eaten
  • Technical skills
  • Ideas and concepts (religion, science theories)
  • Clothing and housing
  • Language
  • Art/music etc
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21
Q

What is technological evolution?

A

Technological evolution refers to changes in technology (ie application of science by humans) which gives humans increased control over their environment.
Eg. tools, machines, robots, medical procedures.

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22
Q

Examples of technological evolution?

A
  • development of stone tools by prehistoric humans
  • development of the printing press
  • radio and television, iPods etc
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23
Q

Definition of hominoids

A

•Hominoid: broad group of primates, consisting of great apes, humans and gibbons

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24
Q

What does the Out of Africa hypothesis state and what are the evidences in support of it?

A

Homo sapiens evolved in Africa 100,000 years ago, then migrated out to other countries.

Evidence:
-Molecular evidence eg mtDNA, chromosome data show greater variation in African populations vs other population since there is more time available for mutations to accumulate in DNA of African individuals

-Transitional fossils for human evolution found in Africa

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25
Q

What does the parallel evolution hypothesis state and what evidences are available for it?

A

•States that: Homo erectus moved out from Africa to other continents. Homo sapiens species evolved parallel to each other on different continents
Evidence: presence of transitional fossils in many other areas eg H. florensiensis in Java, H. erectus skulls in China

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26
Q

What is biological evolution and what are the features associated with it?

A

•Changes in the gene pool of a population that have resulted from natural selection acting over generations.
Features:
•Very slow
•Traits transmitted only via parents
•Transmission can occur only from one generation to the next
•Acquired traits cannot be transmitted
•No choice which genetic traits will be inherited
•Transmission by genetic material (DNA)
•Not planned

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27
Q

What is selective breeding?

A

The deliberate selection by a breeder of specific animals or plants to provide the genetic material for the gene pool of the next generations. (ie which animals will breed)

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28
Q

What are some features that are selected for in beef cattle, dairy cattle and merino rams?

A
Beef cattle:
-Bulls chosen for desirable market characteristics e.g meat yield and non-fatty carcass
Dairy cattle:
-milk yield 
-butterfat content
Merino rams: 
-reduced fibre diameter (finer wool) 
-increase in length+strength of wool staple
-increased yield
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29
Q

What are some examples of reproductive technologies associated with selective breeding?

A
  • Artifical insemination
  • Sex selection through sperm sorting
  • Multiple ovulation and embryo transfer (MOET)
  • Oestrus synchronisation
30
Q

What is artificial selection?

A

*Action taken by breeders and others in selecting from a population only those members that show specific expression of a particular trait to be the parents of the next generation.
Artificial selection occurs when breeders favour particular inherited features in their livestock (because of their economic value or aesthetic appeal) and use selective breeding to enhance those features and to increase their frequency.

31
Q

What is artificial insemination (AI)?

A

Artificial insemination involves collecting semen from a desirable male and inserting it into the reproductive tract of the desired female.

32
Q

Advantages of AI?

A

One prize stud animal can:

  • fertilize many more females under natural conditions
  • fertilize females located hundreds or thousands of kilometres distant from that stud animal because its frozen sperm can be easily transported over great distances.
  • fertilize female animals and produce offspring long after its death
33
Q

What are the consequences/disadvantages to AI?

A
  • use of small number of studs in a breeding program means genetic variation is reduced compared to situation where random mating occurred.
  • potential valuable alleles (such as disease resistance) will be lost from composition of the herd because other inherited features are ignored.
34
Q

What is multiple ovulation embryo transfer?

A

Multiple ovulation involves injecting a desirable female organism (e.g. a cow) with hormones (FSH) in order that she has multiple ovulations and all the eggs mature at the one time.
Embryo transfer can then take place where 6-7 day old embryos are removed from the desirable cow and transplanted int the reproductive tracts of other cows. which then act as surrogate mothers.

35
Q

Advantages of MOET?

A
  • Same mother can supply eggs for multiple offspring
  • Many desirable calves can be born from cattle that do not necessarily possess the desirable characteristics themselves.
36
Q

Disadvantages of MOET?

A

*Decreased genetic variation by restricting number of breeding ewes for example

37
Q

What is sex selection through sperm sorting?

A

Process of producing offspring, predominantly of one sex, by artificially separating sperm from a semen sample into this with X chromosomes and those with Y chromosomes and adding fluorescent dyes that bind to DNA. The sperm with two X chromosomes will fluoresce more brightly as they are larger and contain more DNA.

38
Q

What is artificial pollination in plants?

A

Similar to artificial insemination but pollen used in fertilization of the stigma of the female plant instead.

39
Q

What is embryo splitting?

A

The process of splitting the totipotent cells of a very early embryo so that the resultant cells are each able to form a complete embryo

40
Q

What are the steps involved in Somatic Cell Nuclear Transfer (SCNT) in use for reproductive cloning?

A

Step 1: The nucleus of an egg is removed.
Step 2: The donor cell is starved. The absence of nutrients causes the cell to enter a suspended state, matching the state of an enucleated egg cell.
Step 3: The donor cell is placed near the egg cell and an electric current is used to fuse the cells together and stimulate development. The donor’s cell’s nucleus directs the development of the egg cell. (Note: A microinjection can also be used to transfer the nucleus from the donor cell into the enucleated cell)
Step 4: The developing egg is placed in a sheep oviduct for around six days. The oviduct acts as an incubator as the egg grows into an embryo and continues to develop.
Step 5: After developing in an oviduct for around six days, the embryo is transplanted into the uterus of a surrogate mother ewe. The ewe will carry the developing sheep until it is born.
Step 6: After a normal pregnancy, a clone is form. The clone is an exact genetic duplicate of the animal which provided the adult donor cells.

41
Q

What are the advantages of cloning?

A
  • Possible technology for those unable to reproduce naturally (age, illness, infertility) to do so
  • Possible to obtain many offspring in a short period of time
  • offspring is identical to parent supplying nucleus/somatic cell
  • source for tissue transplants
  • allows breeders to study the effect that the genotype interacting with the environment has on the animal so they can make environment ideal for the animals.
  • ensure organism have desirable market traits
  • endangered species cloned to prevent extinction
42
Q

What are the disadvantages associated with cloning?

A
  • Reduced genetic variation leading to reduced survival
  • Low success rate (many attempts to create a stable, viable egg)
  • Premature ageing in offspring due to shortening of telomeres (if older somatic cells are used)
  • Ethical and religious concerns
43
Q

What are transgenic organisms?

A

Organisms that carry in their genomes one or more genes artificially introduced from another species.

44
Q

What are genetically modified organisms?

A

An organism whose genetic makeup has been altered by artificial means. (when gene is altered from the same or different organism and inserted back into the organism.) 1

45
Q

What is the relationship between GMOs and TGOs?

A

All TGOs are GMOs but not all GMOs are TGOs.

46
Q

What is gene therapy and what is its aim?

A

Introduction into a tissue or organ of specific DNA to replace/compensate for a defective disease-causing allele.
Gene therapy aims to add copies of the normal allele of a gene into the cells of a target tissue, switching them on to produce the functional protein that is missing in a person with a particular disorder.

47
Q

What are the issues concerned with gene therapy?

A
  • Ethical issues ensuring that the inserted gene doesn’t interfere with other essential genes (they can activate sleeping cancer cells etc)
  • Germline gene therapy is banned in humans at the moment.
  • If a virus vector used, the virus has a chance of being reactivated.
48
Q

What are stem cells?

A

Stem cells are undifferentiated or precursor cells that have the ability to differentiate into many different and specialised cell types.

49
Q

What are embryonic stem cells?

A

Cells from the inner cell mass of an early embryo that are pluripotent and can hence give rise to many different cell types. (blood, liver, skin cells)

50
Q

What are somatic (adult) stem cells?

A

Cells that can be obtained from bone marrow, skin, umbilical cord blood that are multipotent and hence give rise to various kinds of blood cells or skin cells.

51
Q

Steps involved in therapeutic cloning?

A

1)Disease free somatic cells taken from the patient
2)Nuclear transfer fusion of cell to enucleated egg
3) The egg(with somatic cell information) undergoes mitosis to form an embryo
4) Embryo cultured and stem cells removed
5) Embryonic stem cells cultured and specific types obtained
The stem cells would be encouraged to grow into whatever tissue or organ is needed to treat the patient. Stem cells are a unique form of human cell that can theoretically develop into many organs or body parts the body.
6) Required cell types introduced into patient. The tissue or organ would be transplanted into the patient.

52
Q

Ethical issues raised with therapeutic cloning?

A
  • Destruction of embryo with human potential

* Interfering with natural processes

53
Q

Difference between transgenic and transfected organisms?

A

*Prokaryotic cells are transformed and eukaryotic cells are transfected in relation to gene technology.

54
Q

What is genetic screening?

A

Genetic screening is a process in which DNA from an individual is tested for the presence of particular alleles responsible for inherited diseases or susceptibility to a disorder.
Testing of persons to detect those with the allele responsible for a particular inherited genetic disorder.

55
Q

What are the advantages of genetic screening?

A
  • Identification of carriers of diseases in adults
  • pre-natal screening using CVS or amniocentesis
  • predictive screening (identifying person at risk of Huntington’s disease)
56
Q

Disadvantages of genetic screening?

A
  • “designer babies”
  • costly some cannot afford
  • genetic discrimination in companies looking fr elitists
57
Q

What is a power grip?

A

A power grip is the typical grip of the human hand when exerting force on a held object. This is in contrast to the precision grip that enables precise and delicate manipulation.

58
Q

What can be concluded from the examination of the zygomatic arch in fossils?

A

The strength of the bite of the species.
*One important muscle that closes the jaw when we chew or bite passes from the jaw through the space behind the zygomatic arch to the top of the skull. The size of this space indicates the size of this muscle and gives an indication of the strength of a bite — the larger the space, the larger the muscle and the stronger the bite.

59
Q

What evidence, if any, exists for tool use in the australopithecines?

A

Bones, smashed probably by use of stones, have been found and have been dated to the same age as Australopithecus fossils found in the same region.

60
Q

What was the first hominin species to make controlled use of fire?

A

Homo erectus

61
Q

What was the first hominin species to eat meat as part of their diet?

A

Homo habilis

62
Q

First human species to leave Africa?

A

Home erectus

63
Q

What is a clinal gradation and what are some examples?

A

A clinal graduation is a gradual change in a trait across a geographic range, such as from the equator to the poles or from sea level to a mountain top. Examples of clinal graduations in human populations include:
• changes in skin pigmentation of indigenous populations from dark in equatorial regions to very light skinned in high latitudes
• changes in body shape with latitude and climate.

64
Q

What are the differences between cultural evolution and biological evolution?

A

Biological evolution:
• is a slow process in which transmission occurs via DNA
• occurs only from parents to offspring
• acts from one generation to the next with no choice of traits to be transmitted.
Cultural evolution:
• is a much faster process in which transmission is through written spoken or signed language
• can occur between unrelated persons and within one generation
• allows choice about what is accepted by an individual.

65
Q

An example of an interaction between cultural, biological and technological evolution?

A

*Tool making.
Biological evolution contributed to tool making because it led to:
• bipedal upright walking in hominins, which freed the hands
• increased brain capacity, which enabled solving of more complex problems.
Cultural evolution/change was the development of tool making in early human species, initially based on the use of stone tools to make tools.
Over time, tool-making technology evolved so that new materials, including metals, were used both in tool making and in new kinds of tools that were fashioned.

66
Q

What are some of the features that contribute to bipedalism and how do they contribute?

A

a) Foramen magnum positioned towards middle of skull – spine protruding from directly below skull OR support weight of head when walking bipedally
b) S shape of the spine – provides support/ balance for upright bipedal walking
c) Bowl shaped pelvis – support weight of internal organs
d) Shorter hip bone – allowing more freedom in movement of legs
e) Longer femur – suggests taller organism with more freedom and easier movement (longer strides)
f) Position of knee joint is directly below pelvis. – appropriate centre of gravity so weight can be supported on 1 leg
g) Big toe is aligned with other toes– allowing for balance when walking on two legs.

67
Q

What are the five benefits of being bipedal?

A

Benefit 1: Freed up use of two hands (appendages)
Reason: Freeing up of these two appendages allowed a more appropriate and required use of hands with the advantage to grasp objects (2 marks)
NOTE: we will not accept “to allow the organism to use tools” because although Australopithecines were bipedal, they did not use tools.

Benefit 2: Appear more threatening
Reason: By appearing taller to other creatures, they appear to be more threatening and not as easy target for predators that might be hunting the early hominids (2 marks)

Benefit 3: Ability to see further/Heightened posture
Reason: When moving through environments that had taller grass it was easier to see ahead and where they were going and to keep a lookout for predators (2 marks)

Benefit 4: Ability to survive hotter climate
Reason: By dissipating excess body heat, they reduce the absorption of heat from the sun because less skin has an exposure to UV radiation during the hottest times of the day/ smaller SA in contact with midday sun (2 marks)

Benefit 5: Bigger strides
Reason: Faster escape from predators

68
Q

What are the ethical concerns in regards to gene therapy?

A
  • The sufferers would live longer and potentially produce more offspring than would have been possible without treatment. The frequency of these alleles for these conditions may increase in the population.
  • Should gene therapy be restricted to somatic tissues only? (gene therapy of germline cells is currently banned)
  • Virus may reactivate, causing disease in the patient
  • The procedure may not be entirely safe for the patient
  • Insertion of this gene may occur within or around other genes, resulting in the disruption of gene function, or the increased/decreased expression of other genes
  • If germline therapy was carried out, the patient’s offspring is affected. This would reduce the frequency of the allele. Perhaps there may be a heterozygous advantage to having the allele in another environment.
  • This treatment is expensive—could lead to only rich people being able to afford it
69
Q

What are the positive impacts of captive breeding?

A
  • captively produced animals can be released back into the wild to boost population numbers of endangered species
  • can save animals from extinction if their natural habitat becomes destroyed/polluted
  • provide opportunities for increasing genetic variation of isolated populations
  • allows us to learn more about animals—may provide information on how to save a species
70
Q

What are the negative impacts of captive breeding?

A
  • expensive
  • decrease in genetic variation of captive populations as a result of genetic drift
  • reduced reproductive success of captive animals
  • relaxed selection criteria, so less fit individuals are allowed to survive
  • stress of captivity can cause abnormal and harmful behaviour
  • animals confined and not allowed to live a normal life in the wild
71
Q

Features of mtDNA that make it a powerful evolutionary tracking tool?

A
  • haploid (therefore variation between organisms is due to mutation only, not crossing over and recombination, or independent assortment)
  • mitochondria are maternally inherited (i.e. mother gives her mtDNA to her daughters and sons)
  • single circular (replicated via binary fission)
  • mutations occur more regularly in the non coding regions of mtDNA than nuclear DNA
  • high copy number (every mitochondrion has 2-20 mtDNA molecules, and each cell has 100s of mitochondria)
72
Q

What is gene therapy?

A

Definition: The addition of a normally functioning allele to replace the function of the defective allele of a gene in an organism by use of a vector.
Insertion of a functional allele to replace the function of a defective allele of a gene in an organism.