Module 4.1
Origin of an idea about origins
Glossary:
All words with ‘*’ can be found below, however, some definitions are found within the
text
Evolution: Gradual change or development of something
Biological evolution: Change in the gene pool of a population during the course of
time by processes
Microevolution: Evolution within a species
Macroevolution: The descent of different species from a common ancestor over many
generations
Natural selection: An evolutionary mechanism
Extant: Demonstrate the evolutionary relationships among organisms that are currently
alive
Palaeontological evidence: Study of prehistoric life
Biogeography: Study of where species (both present and extinct) occur and why
Comparative anatomy: Comparing external and internal structures of organisms to find
out their relation
Homologous structures: Structures that have a similar fundamental structure, position
and development
Analogous structures: Structures that are similar in different organisms because they
evolved in a similar environment, rather than being inherited from a common ancestor
Embryology: Studying embryos = similarities and development of an organism can be
assessed
Vestigial organs: Organs or structures that seem to be stunned and have no function
Scientific hypothesis: An idea or possible explanation about something observed that
suggests a question
Scientific theory: General explanation of an important natural phenomenon with a
reliable body of evidence that has developed extensively and repeated observations
and experiments to support it
Peer review researchers: experts in the same field who look for weakness and eros
and make an unbiased evaluation of the piece of research
Archipelago: A group or chain of islands
Gr10 Revision:
, ● Universe started 3,7 bya
● Earth is about 4,6 billion years old
● Earth crust built up over millions of years and consists of water (sedimentary
rocks) or by volcanic activity (volcanic rocks) with the oldest layers at the bottom
● Dating of fossils: relative dating and radiometric dating (absolute dating) can
determine the age of a rock layer and therefore the age of the fossils in the rock
● The 5 mass extinctions: occurred with many species becoming extinct
● By studying fossils one:
○ Learns about ancient forms and the appearance and extinction of
organisms, from individual species to whole taxonomic groups
○ Understands that life-forms changed and gradually become more similar
to the present-day forms
○ Gains evidence to support the idea that species change (evolve)
● South Africa is rich in fossils (important findings):
○ Earliest organisms (3,5 bya), stromatolites - Mpumalanga
○ Primitive land plants - KZN
○ Coelacanth (fish group ancestral to amphibians)
○ Mammal-like reptiles (bridge between reptiles and mammals) -Karoo
○ Humankind’s earliest direct ancestors - Cradle of Humankind
Development of the theory of evolution*:
● Evolution* = Gradual change or development of something
● Biological evolution* = Change in the gene pool of a population during the course
of time by processes (eg: mutation, natural selection and genetic shift)
● Biological evolution, aka descent with modification = covers both micro-
evolution* (evolution within a species and macroevolution* (the descent of
different species from a common ancestor over many generations)
Importance of biological evolution:
● It is the unifying concept that acts as a foundation for understanding all biology
● Supports and explains many aspects of our everyday life
● Challenged people to really think for themselves
The origin of life:
● Current opinion is that there is a single origin of life = supported by the fact that
all life shares the same genetic code and similar basic enzymes but science is a
long way of explaining HOW life originated
How did species diversity originate:
Origin of an idea about origins
Glossary:
All words with ‘*’ can be found below, however, some definitions are found within the
text
Evolution: Gradual change or development of something
Biological evolution: Change in the gene pool of a population during the course of
time by processes
Microevolution: Evolution within a species
Macroevolution: The descent of different species from a common ancestor over many
generations
Natural selection: An evolutionary mechanism
Extant: Demonstrate the evolutionary relationships among organisms that are currently
alive
Palaeontological evidence: Study of prehistoric life
Biogeography: Study of where species (both present and extinct) occur and why
Comparative anatomy: Comparing external and internal structures of organisms to find
out their relation
Homologous structures: Structures that have a similar fundamental structure, position
and development
Analogous structures: Structures that are similar in different organisms because they
evolved in a similar environment, rather than being inherited from a common ancestor
Embryology: Studying embryos = similarities and development of an organism can be
assessed
Vestigial organs: Organs or structures that seem to be stunned and have no function
Scientific hypothesis: An idea or possible explanation about something observed that
suggests a question
Scientific theory: General explanation of an important natural phenomenon with a
reliable body of evidence that has developed extensively and repeated observations
and experiments to support it
Peer review researchers: experts in the same field who look for weakness and eros
and make an unbiased evaluation of the piece of research
Archipelago: A group or chain of islands
Gr10 Revision:
, ● Universe started 3,7 bya
● Earth is about 4,6 billion years old
● Earth crust built up over millions of years and consists of water (sedimentary
rocks) or by volcanic activity (volcanic rocks) with the oldest layers at the bottom
● Dating of fossils: relative dating and radiometric dating (absolute dating) can
determine the age of a rock layer and therefore the age of the fossils in the rock
● The 5 mass extinctions: occurred with many species becoming extinct
● By studying fossils one:
○ Learns about ancient forms and the appearance and extinction of
organisms, from individual species to whole taxonomic groups
○ Understands that life-forms changed and gradually become more similar
to the present-day forms
○ Gains evidence to support the idea that species change (evolve)
● South Africa is rich in fossils (important findings):
○ Earliest organisms (3,5 bya), stromatolites - Mpumalanga
○ Primitive land plants - KZN
○ Coelacanth (fish group ancestral to amphibians)
○ Mammal-like reptiles (bridge between reptiles and mammals) -Karoo
○ Humankind’s earliest direct ancestors - Cradle of Humankind
Development of the theory of evolution*:
● Evolution* = Gradual change or development of something
● Biological evolution* = Change in the gene pool of a population during the course
of time by processes (eg: mutation, natural selection and genetic shift)
● Biological evolution, aka descent with modification = covers both micro-
evolution* (evolution within a species and macroevolution* (the descent of
different species from a common ancestor over many generations)
Importance of biological evolution:
● It is the unifying concept that acts as a foundation for understanding all biology
● Supports and explains many aspects of our everyday life
● Challenged people to really think for themselves
The origin of life:
● Current opinion is that there is a single origin of life = supported by the fact that
all life shares the same genetic code and similar basic enzymes but science is a
long way of explaining HOW life originated
How did species diversity originate:
