SCSA Human Biology Hominid evolutionary trends
15 sample questions with marking guides and sample answers · Avg. score: 50%
Scientists suggest that some hominin adaptations, including an upright stance and bipedal locomotion, were associated with a drier habitat and expanding grasslands.
Which of the following best explains the advantage of an upright stance and bipedal locomotion in the African savannah? It
allowed hominins to climb trees more effectively to escape predators in open grasslands.
increased the ability of hominins to spot prey and forage for food over long distances.
increased upper body strength so hominins could gather and carry larger quantities of food.
allowed hominins to develop faster running speeds, allowing them to outrun predators.
Reveal Answer
allowed hominins to climb trees more effectively to escape predators in open grasslands.
Bipedalism and an upright stance actually decreased tree-climbing efficiency, as hominins lost the grasping feet and specialized limb proportions that make other apes excellent climbers.
increased the ability of hominins to spot prey and forage for food over long distances.
An upright stance provided a higher vantage point to see over tall savannah grasses, while bipedal locomotion was highly energy-efficient for traveling long distances to find scattered food sources.
increased upper body strength so hominins could gather and carry larger quantities of food.
While bipedalism freed the hands to carry food, it did not increase upper body strength. In fact, hominins generally have less upper body strength compared to their quadrupedal ape relatives.
allowed hominins to develop faster running speeds, allowing them to outrun predators.
Bipedal hominins are generally slower runners than quadrupedal animals. Bipedalism evolved for endurance and energy efficiency over long distances, not for sprinting to outrun predators.
Neanderthals and early Homo sapiens share a common ancestor that originated in Africa. By the time modern humans left Africa around 300 000 years ago, Neanderthals had been living in Europe and Asia for approximately 100 000 years.
Early genetic studies identified around 0.02% of Neanderthal DNA in genomes of modern Africans. New research has identified that those with African ancestry have closer to 0.5% Neanderthal DNA. The same study found that Neanderthal DNA contributed 1.7% to European genomes and 1.8% in Asian genomes.
Suggest two possible ways in which people with African ancestry could have some Neanderthal DNA in their genomes.
Reveal Answer
Possible ways that people with African ancestry could have Neanderthal DNA in their genomes included:
- Ancestors of modern Africans could have interbred with Neanderthals before migrating from Africa.
- Ancestors of modern Africans left Africa and interbred with Neanderthals already in Europe and Asia, before returning to Africa.
- Modern-day Africans still carry Neanderthal DNA that was shared DNA from their common ancestor.
| Descriptor | Marks |
|---|---|
1 mark for each correct point (any 2 of):
| 2 |
Suggest why it is reasonable that modern Europeans and Asians show greater percentages of Neanderthal DNA than people who originated in Africa.
Reveal Answer
Possible reasons why modern Europeans and Asians show a greater percentage of Neanderthal DNA included:
- Homo sapiens coexisted with Neanderthals for a longer period of time in Europe and Asia, so more opportunities existed for interbreeding.
- Homo sapiens who originated in Africa did not coexist or interbreed with Neanderthals, as Neanderthals did not live in Africa.
| Descriptor | Marks |
|---|---|
1 mark for each correct point (any 2 of):
| 2 |
Human-made objects associated with the remains of Homo species are best described as
tools.
artefacts.
artifices.
fossils.
Reveal Answer
tools.
While tools are a type of human-made object, this term is too narrow, as it excludes other manufactured items like pottery, clothing, or ornaments.
artefacts.
"Artefacts" (or artifacts) is the broad archaeological term used to describe any physical object made, modified, or used by humans or human ancestors.
artifices.
An artifice refers to a clever trick, deception, or cunning device, rather than a physical historical object created by early humans.
fossils.
Fossils are the preserved remains or traces of biological organisms (such as bones or footprints), not inanimate objects manufactured by humans.
The human hand can be distinguished from most other primates by its
extra bones in the wrist that increase strength but reduce flexibility.
opposable thumb that improves dexterity and allows for a precision grip.
long, curved finger bones that enable a power grip to exert force.
long and narrow palm that is designed for efficient grasping and climbing.
Reveal Answer
extra bones in the wrist that increase strength but reduce flexibility.
Humans do not have extra wrist bones compared to other primates; our wrist structure is actually adapted for a balance of flexibility and strength.
opposable thumb that improves dexterity and allows for a precision grip.
While many primates have opposable thumbs, the human thumb is relatively longer and more mobile, allowing for a unique pad-to-pad precision grip that is essential for fine motor tasks and tool use.
long, curved finger bones that enable a power grip to exert force.
Long, curved finger bones are characteristic of arboreal primates (like chimpanzees) for climbing and hanging, whereas human fingers are shorter and straighter.
long and narrow palm that is designed for efficient grasping and climbing.
Humans actually have a relatively short and broad palm compared to the long, narrow palms of many other primates that are adapted for climbing.
Until May 2019, Denisovan fossils had been found in only two locations: Siberia and Tibet. Since then, Denisovan DNA has been discovered in some present-day populations. These populations are found on several continents, including Australia.
This suggests that the ancient Denisovan hominin group was or its descendants were
only fossilised in Siberia and Tibet.
genetically identical to Homo sapiens.
extinct prior to the presence of Neanderthals.
more widespread than fossil evidence suggests.
Reveal Answer
only fossilised in Siberia and Tibet.
While fossils have only been found in Siberia and Tibet so far, the presence of their DNA in modern populations across multiple continents suggests they likely lived and died elsewhere too.
genetically identical to Homo sapiens.
If they were genetically identical to Homo sapiens, scientists would not be able to distinguish distinct Denisovan DNA in present-day populations.
extinct prior to the presence of Neanderthals.
The prompt provides no information about Neanderthals, and the presence of Denisovan DNA in modern humans indicates they survived long enough to interbreed with our ancestors.
more widespread than fossil evidence suggests.
The discovery of Denisovan DNA in modern populations across several continents indicates that Denisovans or their descendants migrated far beyond the two locations where their fossils have currently been found.
Which of the following lists correctly the development of stone tools manufactured by humans, from earliest to most recent?
pebble tools, bifacial handaxes, flake tools, blades
microliths, handaxes, flake tools, blades
pebble tools, flake tools, hafted tools, handaxes
blades, choppers, spear points, handaxes
Reveal Answer
pebble tools, bifacial handaxes, flake tools, blades
This sequence correctly follows the archaeological record: pebble tools (Oldowan) are the earliest, followed by bifacial handaxes (Acheulean), flake tools (Mousterian), and finally blades (Upper Paleolithic).
microliths, handaxes, flake tools, blades
Microliths are small, advanced stone tools developed much later (during the Mesolithic period), so they should appear at the end of the timeline, not the beginning.
pebble tools, flake tools, hafted tools, handaxes
Handaxes (Acheulean) were developed much earlier than hafted tools, which involve the more advanced technique of attaching stone points to handles or shafts.
blades, choppers, spear points, handaxes
Blades are an advanced tool type associated with the Upper Paleolithic, while choppers are among the earliest tools. This list starts with a recent tool and places an early tool second.
Compared to the foot of a chimpanzee, the foot of a human has
a single arch running from front to back.
a larger calcaneus bone in the heel.
increased opposability of the first digit.
more flexibility in the ankle joint.
Reveal Answer
a single arch running from front to back.
Humans actually have two arches in their feet (longitudinal and transverse) to absorb shock during bipedal walking, not just a single arch.
a larger calcaneus bone in the heel.
Humans have a significantly larger calcaneus (heel bone) to absorb the impact and support the body's weight during bipedal locomotion.
increased opposability of the first digit.
Humans have a non-opposable big toe that aligns with the other toes for efficient walking, whereas chimpanzees have a highly opposable big toe for grasping branches.
more flexibility in the ankle joint.
Human ankle joints are less flexible than those of chimpanzees, providing the necessary stability for upright, bipedal walking rather than climbing.
Which of the following contains adaptations that contribute to bipedalism?
S-shaped curve, increased size of lumbar vertebrae, centralisation of the foramen magnum
C-shaped curve, increased size of lumbar vertebrae, centralisation of the foramen magnum
S-shaped curve, increased size of lumbar vertebrae, long, narrow pelvis
C-shaped curve, increased size of thoracic vertebrae, centralisation of the foramen magnum
Reveal Answer
S-shaped curve, increased size of lumbar vertebrae, centralisation of the foramen magnum
An S-shaped spine, larger lumbar vertebrae, and a centralized foramen magnum all help balance the body's weight vertically over the legs, which are key adaptations for upright walking.
C-shaped curve, increased size of lumbar vertebrae, centralisation of the foramen magnum
A C-shaped spine is characteristic of quadrupeds, not bipeds, as it does not center the upper body's weight over the pelvis.
S-shaped curve, increased size of lumbar vertebrae, long, narrow pelvis
While the spine and vertebrae adaptations are correct, a bipedal pelvis is short and broad (bowl-shaped) to support internal organs and muscle attachments, rather than long and narrow.
C-shaped curve, increased size of thoracic vertebrae, centralisation of the foramen magnum
A C-shaped spine and larger thoracic vertebrae are adaptations for quadrupeds, as they do not support the vertical weight distribution required for an upright posture.
Listed below is a series of characteristics found within the primate group.
I. reduction in olfactory centre of brain
II. non-opposable big toe
III. bipedal gait
IV. flat face
V. pentadactyl limb
Which combination of characteristics makes a hominin different from all other primates?
I and III only
II and III only
III, IV and V
I, III and IV
Reveal Answer
I and III only
While hominins do have a bipedal gait (III), a reduction in the olfactory centre of the brain (I) is a characteristic shared by many other primates, such as monkeys and apes, so it does not distinguish hominins.
II and III only
Hominins are uniquely defined among primates by their bipedal gait (III) and the associated skeletal adaptation of a non-opposable big toe (II) which provides thrust during upright walking.
III, IV and V
A pentadactyl (five-digit) limb (V) is a primitive trait found in all primates and most tetrapods, meaning it cannot be used to differentiate hominins from other primates.
I, III and IV
A reduction in the olfactory centre (I) and a relatively flat face (IV) are evolutionary trends seen across various primate lineages, not just hominins, making this combination incorrect.
Why is a centrally positioned foramen magnum in humans an advantage for bipedal locomotion? It
helps humans to jump higher by improving head movement.
increases height, so humans can reach higher and see further distances.
allows the skull to balance directly on the spinal column.
allows the skull to rotate freely, making it easier to turn the head while walking.
Reveal Answer
helps humans to jump higher by improving head movement.
The position of the foramen magnum does not affect jumping ability. Its primary evolutionary advantage is related to upright posture and balance, not vertical propulsion.
increases height, so humans can reach higher and see further distances.
The central position of the foramen magnum aligns the head with an upright spine, but it does not physically increase a person's height.
allows the skull to balance directly on the spinal column.
A centrally located foramen magnum places the center of gravity of the head directly over the spine. This minimizes the muscular effort required to keep the head upright during bipedal walking.
allows the skull to rotate freely, making it easier to turn the head while walking.
Head rotation is primarily facilitated by the specialized atlas and axis vertebrae in the neck, rather than the central positioning of the foramen magnum.
Which of the following correctly lists features associated with the evolutionary trend in primates and hominins relating to locomotion?
broader pelvis, increased number of arches in the feet, shorter arm length and opposability of the thumb
narrower pelvis, opposability of the thumb, longer arm length and increased number of curves in the spine
decreased number of curves in the spine, decreased number of arches in the feet, shorter arm length and narrower pelvis
non-opposable big toe, increased number of curves in the spine, increased number of arches in the feet and broader pelvis
Reveal Answer
broader pelvis, increased number of arches in the feet, shorter arm length and opposability of the thumb
While a broader pelvis and foot arches are adaptations for bipedalism, the opposability of the thumb is an evolutionary trait associated with grasping and fine motor manipulation, not locomotion.
narrower pelvis, opposability of the thumb, longer arm length and increased number of curves in the spine
Hominin evolution for bipedalism is characterized by a broader (not narrower) pelvis and shorter (not longer) arms. Additionally, the opposable thumb is related to tool use and manipulation rather than movement.
decreased number of curves in the spine, decreased number of arches in the feet, shorter arm length and narrower pelvis
This option lists the opposite of the actual evolutionary trends; bipedalism requires an increased number of spinal curves and foot arches for shock absorption, as well as a broader pelvis to support the upper body.
non-opposable big toe, increased number of curves in the spine, increased number of arches in the feet and broader pelvis
These are all key adaptations for efficient bipedal locomotion: a non-opposable big toe provides thrust, an S-shaped spine and foot arches absorb shock, and a broader pelvis supports upright posture.
Species of the genus Homo do not possess the powerful jaw muscles commonly found in the genera Australopithecus and Paranthropus. According to the fossil record, this decrease in the size of jaw muscles coincided with changes in brain size. Scientists have discovered that both the reduction in the size of the jaw muscles and the change in brain size occurred due to mutations.
Describe the various types of mutations, identify the causes and describe how they can occur.
Reveal Answer
A mutation is a change in a gene or a chromosome, leading to new characteristics in an organism or their offspring.
Mutations can be gene mutations or chromosomal mutations. Gene mutations are changes in a single gene which occur during DNA replication, while chromosomal mutations affect all or part of a chromosome. Mutations can also be somatic or germline. Somatic mutations occur in the body cells, meaning reproductive cells are not affected and therefore the mutation is not passed on to offspring. Germline mutations occur in the reproductive cells or gametes, and therefore can be passed on to offspring.
Mutations can be caused by mutagenic agents, which are substances that are known to increase the rate at which mutations occur, such as ionising radiation (e.g. X-rays), mustard gas, formaldehyde, and some antibiotics. Mutations can also be caused by errors in DNA replication, resulting in deletion where part of a chromosome is lost, duplication where a section of chromosome is repeated or occurs twice, etc. Finally, mutations can be caused by errors in cell division, leading to inversion where a broken part of a chromosome joins back but in the wrong way, translocation where part of a chromosome breaks off and re-joins to the wrong chromosome, etc.
Define
| Descriptor | Marks |
|---|---|
Defines a mutation as a change in a gene or a chromosome (leading to new characteristics in an organism or their offspring) | 1 |
Types of mutations
| Descriptor | Marks |
|---|---|
1 mark for each valid point (up to 3 marks):
| 3 |
1 mark for each valid point (up to 3 marks):
| 3 |
Causes - Mutagens
| Descriptor | Marks |
|---|---|
States mutations are caused by mutagens/mutagenic agents | 1 |
Defines mutagens as substances that are known to increase the rate at which mutations occur (e.g. ionising radiation, mustard gas, formaldehyde, some antibiotics) | 1 |
Causes - DNA replication
| Descriptor | Marks |
|---|---|
States mutations are caused by errors in DNA replication | 1 |
1 mark for each valid point (up to 2 marks): Deletion: part of a chromosome is lost; Duplication: section of chromosome is repeated/occurs twice; Insertions: DNA can be duplicated/extra DNA added; Frameshifts: incomplete DNA code/unreadable DNA code | 2 |
Causes - Cell division
| Descriptor | Marks |
|---|---|
States mutations are caused by errors in cell division/meiosis | 1 |
1 mark for each valid point (up to 2 marks): Inversion: broken part of chromosome joins back but in the wrong way; Translocation: part of chromosome breaks off and re-joins to the wrong chromosome; Non-disjunction: during meiosis, a chromosome pair does not separate so one daughter cell has an extra chromosome and one daughter cell has one less (aneuploidy) | 2 |
Explain how the example of the evolution of the unique hominin jaw illustrates the importance of mutations to evolution.
Reveal Answer
Mutations introduce new alleles into a population. Hominin jaw mutations must have been an advantage to survival, as the organisms are better suited to bipedal locomotion. These favourable alleles are passed onto offspring, meaning the mutation is maintained in future generations.
| Descriptor | Marks |
|---|---|
Award 1 mark for each of the following points, up to a maximum of 5 marks:
| 5 |
It is estimated that millions of hominins pre-dating the modern Homo sapiens have populated the Earth and yet only 6000 individuals are represented in the hominin fossil record.
Explain why there are so few fossils in the fossil record.
Reveal Answer
Generally only hard or solid parts, such as bones and teeth, are fossilised. Organisms need to ‘die’ in an area suitable to fossilisation, and the sediments or soils need to be of the right conditions. Organisms need to be protected from decay from microorganisms, and the remains need to be undisturbed by scavengers. The remains need to be quickly covered by sediments for rapid burial, and the sediments need to be undisturbed by geological processes. Many fossils are buried too deep to be found. Many fossils are destroyed by geological processes or human activity, and many fossils are not recognised as being so. Finally, many fossils once exposed are eroded or weathered.
| Descriptor | Marks |
|---|---|
1 mark for each correct point (any 10 of): Generally only hard/solid parts e.g. bones/teeth are fossilised; Organisms need to ‘die’ in area suitable to fossilisation; The sediments/soils needs to be of the right conditions/alkaline/low oxygen levels; Organisms need to be protected from decay from microorganisms; The body/remains need to be undisturbed by scavengers; The body/remains need to be quickly covered by sediments/rapid burial; The soil/sediments need to be undisturbed by geological processes; Many fossils are buried too deep to be found/not exposed to the surface; Many fossils are destroyed by geological processes/human activity; Many fossils are not recognised as being so/people don’t recognise them; Many fossils once exposed are eroded/weathered | 10 |
Explain, using examples, how the comparative studies of anatomy can be used for the construction of phylogenetic trees.
Reveal Answer
Any 2 of comparative embryology, homologous structures, or vestigial organs
For comparative embryology:
We compare anatomical structure during embryo development. Organisms share similar anatomical structures during early development, which indicates shared common ancestry. The more similar the structures are for longer in the embryonic stage, the more closely placed together they are on phylogenetic trees. An example is gill slits and a tail found in vertebrate embryos.
For homologous structures:
We compare anatomical structure from different species. Structures show a high degree of structural similarity but perform different functions, which indicates shared common ancestry. The more similar the structures are, the more closely placed together they are on phylogenetic trees. An example is the bone structure in the vertebrate limbs.
For vestigial organs:
These are homologous structures that have a benefit in some species, but are present but not functional in other species. This indicates shared common ancestry. More shared features mean they are more closely placed together on phylogenetic trees. An example is wisdom teeth in humans.
Example 1
| Descriptor | Marks |
|---|---|
1 mark for each correct point for one chosen example: Comparative embryology (Compares anatomical structure during embryo development/stages of embryo development from different species; States that organisms share similar anatomical structures during early development; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the basic structure; Explains that the more similar the structures are for longer in the embryonic stage = more closely placed together on phylogenetic trees; Provides an example); OR Homologous structures (Compares anatomical structure from different species; States that structures show a high degree of structural similarity but perform different functions; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the basic structure; Explains that the more similar the structures are = more closely placed together on phylogenetic trees; Provides an example); OR Vestigial organs (Describes homologous structures that have a benefit/normal function in some species; States that they are present but not functional in other species; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the structure; Explains that more shared features = more closely placed together on phylogenetic trees; Provides an example). | 5 |
Example 2
| Descriptor | Marks |
|---|---|
1 mark for each correct point for a second chosen example: Comparative embryology (Compares anatomical structure during embryo development/stages of embryo development from different species; States that organisms share similar anatomical structures during early development; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the basic structure; Explains that the more similar the structures are for longer in the embryonic stage = more closely placed together on phylogenetic trees; Provides an example); OR Homologous structures (Compares anatomical structure from different species; States that structures show a high degree of structural similarity but perform different functions; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the basic structure; Explains that the more similar the structures are = more closely placed together on phylogenetic trees; Provides an example); OR Vestigial organs (Describes homologous structures that have a benefit/normal function in some species; States that they are present but not functional in other species; Explains that this indicates shared common ancestry/at one point they all shared an ancestor who had the structure; Explains that more shared features = more closely placed together on phylogenetic trees; Provides an example). | 5 |
Researchers in Ethiopia found a relatively complete hominin skeleton. Looking at the skeleton it was not clear which form of locomotion the hominin had used. The specimen showed features that could be linked with both bipedalism and brachiation.
Identify six anatomical features of the skeleton that could have been present in the shoulders, arms, and hands to support brachiation as a means of locomotion, and explain how the shoulders, arms and hands allow for brachiation.
Reveal Answer
Features of brachiation include:
- Shoulders with a reduced clavicle, high shoulder blades, and a backwards facing socket of the scapula.
- Longer arms and a flexible elbow joint.
- The hands have long, curved fingers, short thumbs, and a robust but flexible wrist joint.
These features are adapted for swinging in trees. The hands are adapted to grasp branches. These adaptations provide strength to support the weight of the hominin in trees and create an energy efficient pattern of movement.
| Descriptor | Marks |
|---|---|
1 mark for each correct point (any 6 of, with at least one from each category):
| 6 |
Explains that these features are adapted for swinging in trees, circular arm movements, or flexibility of arms to rotate | 1 |
Explains that hands are adapted to grasp branches or hang from branches | 1 |
States that these adaptations provide strength to support the weight of the hominin in trees | 1 |
Concludes that this creates an energy efficient pattern of movement | 1 |
Identify two anatomical features of the skeleton that could have been present in the pelvis to support bipedalism as a means of locomotion, and outline how these features would allow for bipedalism.
Reveal Answer
The pelvis: short, broad, and bowl-shaped pelvis
These features ensure support of body organs and help propel the body forward during locomotion.
| Descriptor | Marks |
|---|---|
1 mark for each correct point (any 2 of):
| 2 |
1 mark for each correct point (any 2 of):
| 2 |
Researchers were unable to provide an actual date for the fossil skeleton. They were however, able to use stratigraphy to date the fossil.
Name and describe two ways in which stratigraphy is employed to date a fossil.
Reveal Answer
The principle of superposition states that the youngest rocks are at the top, while the oldest are underneath, meaning fossils higher in the layers are younger.
The correlation of rock strata involves rock strata from one location being matched with another location, so fossils in matching rock strata are the same age.
| Descriptor | Marks |
|---|---|
Identifies the principle of superposition | 1 |
Explains that the youngest rocks are at the top, while the oldest are underneath | 1 |
States that fossils higher in the layers are younger | 1 |
Identifies the correlation of rock strata | 1 |
Explains that rock strata from one location are matched with another location | 1 |
States that fossils in matching rock strata are the same age, or mentions matching index fossils to determine age | 1 |
In 1998, archaeologists discovered the skeleton of a four-year-old-boy in Abrigo do Lagar Velho, Portugal. The specimen had been carefully buried and surrounded by pierced deer teeth and shell ornaments. The age of the skeleton was dated to around 25 000 years. The specimen has been described as 'the hybrid child' as the skull, pelvis and forearms were similar to modern humans, yet the knee and leg were more similar to Homo neanderthalensis.
Identify three features of the skull that would suggest the specimen is closely related to Homo sapiens, and three features of the knee and leg that would suggest it is closely related to Homo neanderthalensis.
Reveal Answer
For the skull, features include a rounded or high braincase, a cranial capacity of , the presence of a chin, small teeth, a lack of brow ridges, and a flat face with no prognathism.
For the knee and leg, features include short limbs, thick bones, strong joints, and a large outer hinge in the knee joint.
Skull features
| Descriptor | Marks |
|---|---|
1 mark for each correct point (any 3 of):
| 3 |
Knee and leg features
| Descriptor | Marks |
|---|---|
1 mark for each correct point (any 3 of):
| 3 |
Name the tool culture associated with Homo neanderthalensis and explain how the different types of neanderthal tools provide evidence of their advanced lifestyle.
Reveal Answer
The tool culture is Mousterian.
This culture included scrapers, blades, and handaxes, which were able to prepare animal hides for clothing, build shelters, or remove meat from animal bones.
They also used burin tools, which were able to engrave or carve materials and produce other tools.
Spears or points were hafted to a shaft or handles, making them able to hunt larger animals.
Furthermore, there was the use of a wider range of materials such as teeth, shells, and bones, which made them able to make more specialised tools or have specialised roles.
Name of tool culture
| Descriptor | Marks |
|---|---|
Identifies the tool culture as Mousterian | 1 |
Explanation
| Descriptor | Marks |
|---|---|
Identifies scrapers/knives/blades/handaxes | 1 |
Explains scrapers/knives/blades/handaxes were able to prepare animal hides for clothing/build shelters/remove meat from animal bones | 1 |
Identifies burin tools | 1 |
Explains burin tools were able to engrave/carve materials/produce other tools | 1 |
Identifies spears/points | 1 |
Describes that spears/points were hafted to a shaft/handles | 1 |
Explains spears/points were able to hunt larger animals | 1 |
Identifies the use of a wider range of materials (teeth, shells, bones) | 1 |
Explains use of a wider range of materials were able to make more specialised tools/have specialised roles | 1 |
State two environmental conditions required for the fossilisation of the skeleton, deer teeth and shell ornaments, and justify how each promotes fossilisation.
Reveal Answer
Answers could include:
-
A quick burial under fine sediment is required to prevent decomposition, scavenging, or decay.
-
An absence of decay organisms is needed to allow time for minerals to replace organic tissue.
-
A long period of stability, where it is left undisturbed for a long period of time, is necessary to allow sediment to harden.
-
Alkaline soil is required to prevent the breakdown of organic tissue.
Condition and explanation 1
| Descriptor | Marks |
|---|---|
Identifies a condition (quick burial, absence of decay organisms, long period of stability, or alkaline soil) | 1 |
Explains the identified condition | 1 |
Condition and explanation 2
| Descriptor | Marks |
|---|---|
Identifies a condition (quick burial, absence of decay organisms, long period of stability, or alkaline soil) | 1 |
Explains the identified condition | 1 |