change over time
These changes may occur in chemicals, matter, solar systems and language
Biological evolution
Genetic changes in population of living organisms that are inherited over sucessive generations
due to natural selection and ultimately resulting in the formation of new species
Macro-evolution
The development of new life forms or species from earlier life forms over many generations
(extended geological periods)
Speciation forms the basis of macro-evolution wherenew species develop from existing species
over time
Micro-evolution
The variation that occurs within a species
Small changes originate in the gene pool, resulting in small changes in the genotype of the species
These changes are passed on to the offspring
Hypothesis
sometimes called an informed or educated assumption because it provides a proposed
solution to a problem or an explanation of a scientific phenomenon, based on scientific
evidence or observations
Tested in a series of experiments or by repeated observation (i.e. it is testable depending on
further research)
depending on results, it is tested/rejected
Theory
well-substantiated (supported by evidence) explanation or hypothesis that makes sense of a
natural phenomenon
based on scientific evidence and is usually tested and confirmed by independent groups of
researchers
it develops nd is changed or replaced as new evidence is discovered
Evolution is considered a scientific theory, as it is based on a series of hypotheses that have
been tested and verified over time
Scientisis acknowledge that some aaspects of the theory of evolution are not easily tested and
verified
, The origin and development of life on earth have been a great source of speculation and conflict
from the earliest times
Many scientists support the theory that life on earth arose from a common ancestor 4,6 billion
years ago
It is also commonly accepted that the process of evolution occured where 1 kind of organism
changed into another
Evolutionists believe this process lead to the enormous biodiversity that currently exsists on
earth
EVOLUTION- change over time
1. fossil records
2. modification by descent
3. biogeography
4. genetics
5. other forms of evidence
FOSSIL RECORDS
Fossil- an organism or the remains, imprints or footprints of an organism, usually preserved in rock
fossils provide evidence of the history of extinct organisms on earth
they also give an indication of the climate and environment millions of years ago
Fossil record- the accumulation of all listed and known fossils of different ages that have been
discovered by palaeontologists worldwide
Palaeontology- the study of plant and animal fossils
Palaeontologist- a scientist that studies fossils
few individualsfossilise, possibly because they are soft-bodied and thus they decompose after
death and their structures are not preserved
very specific conditions (rapid burial, high pressure, low oxygen) are essential for fossilisationto
occur
the fossil record is a record of those organisms that were fossilised, however fossil records are
imcomplete and not an indication of all the organisms that exsisted at a specific time
the fossil record contains extinct and living species
scientists expect to find earlier, simpler fossils in the deeper, older rock layers and recent, more
complex fossils in the upper, more recent rock layers
this indicates the order of evolution
the age of fossils is determined from the age of the rock they’re in
older rock strata have less biodiversity which shows that there was an increase in biodiversity
over time
the fossil record contributes to the compilation of a geological time scale from the origin of the
earth until now
the geological time scale shows the increase in complexity over time (prokaryotes to more
diverse)
, The fossil record has many gaps, especially when changing from one organism to
another
Fossils of transitional types are very rare
Archaeopteryx is an example of a transitional fossil
it is known as the earliest and most primitive bird
’It is thetransition between reptiles and birds from the Jurrassic period (150mya) and has bird
and reptile characteristics
Evolutionary scientists like Stephen Jay Gould
and Niles Eldridge have formulated alternative
theories to explain the gaps in the fossil records
MODIFICATION BY DESCENT
the basic body plans of different plant and animal groups were modified to adapt to their
different environments
this phenomenon is known as modification by descent and it provides evidence of evolution
MODIFICATION IN VERTEBRATES:
the forelimbs of various vertebrates like amphibians, reptiles, birds and mammals look different
and perform different functions, but show the same basic body plan
functions include digging, flying, running, swimming and climbing
the basic body plan consists of the following bones:
1. one proximal longbone (humeris)
2. two distal bones (radius and ulna)
3. number of wristbones (carpals)
4. five metacarpals that form the palm
5. phalanges (fingers)
pentacactyl limb= 5 digits (fingers)
similar structures (eg forelimbs) with the same body plan that perform different functions are
known as homologous structures
They show evidence of evolution because similarities may trace to a common ancestor
the changes/adaptations happenindependently in each group according to habitat and mode of
life
, different evolutionary paths Analogous structures- same
common ancestor structures with same function
but no common ancestor
MODIFICATION WITHIN A SPECIES
according to this theory, many species changed over millions of years to form the species we
know today
these modern species are modified descents of earlier species
adaptations/modificiation occurred to adapt to different environments
the evolution of the horse is an example:
These changes may occur in chemicals, matter, solar systems and language
Biological evolution
Genetic changes in population of living organisms that are inherited over sucessive generations
due to natural selection and ultimately resulting in the formation of new species
Macro-evolution
The development of new life forms or species from earlier life forms over many generations
(extended geological periods)
Speciation forms the basis of macro-evolution wherenew species develop from existing species
over time
Micro-evolution
The variation that occurs within a species
Small changes originate in the gene pool, resulting in small changes in the genotype of the species
These changes are passed on to the offspring
Hypothesis
sometimes called an informed or educated assumption because it provides a proposed
solution to a problem or an explanation of a scientific phenomenon, based on scientific
evidence or observations
Tested in a series of experiments or by repeated observation (i.e. it is testable depending on
further research)
depending on results, it is tested/rejected
Theory
well-substantiated (supported by evidence) explanation or hypothesis that makes sense of a
natural phenomenon
based on scientific evidence and is usually tested and confirmed by independent groups of
researchers
it develops nd is changed or replaced as new evidence is discovered
Evolution is considered a scientific theory, as it is based on a series of hypotheses that have
been tested and verified over time
Scientisis acknowledge that some aaspects of the theory of evolution are not easily tested and
verified
, The origin and development of life on earth have been a great source of speculation and conflict
from the earliest times
Many scientists support the theory that life on earth arose from a common ancestor 4,6 billion
years ago
It is also commonly accepted that the process of evolution occured where 1 kind of organism
changed into another
Evolutionists believe this process lead to the enormous biodiversity that currently exsists on
earth
EVOLUTION- change over time
1. fossil records
2. modification by descent
3. biogeography
4. genetics
5. other forms of evidence
FOSSIL RECORDS
Fossil- an organism or the remains, imprints or footprints of an organism, usually preserved in rock
fossils provide evidence of the history of extinct organisms on earth
they also give an indication of the climate and environment millions of years ago
Fossil record- the accumulation of all listed and known fossils of different ages that have been
discovered by palaeontologists worldwide
Palaeontology- the study of plant and animal fossils
Palaeontologist- a scientist that studies fossils
few individualsfossilise, possibly because they are soft-bodied and thus they decompose after
death and their structures are not preserved
very specific conditions (rapid burial, high pressure, low oxygen) are essential for fossilisationto
occur
the fossil record is a record of those organisms that were fossilised, however fossil records are
imcomplete and not an indication of all the organisms that exsisted at a specific time
the fossil record contains extinct and living species
scientists expect to find earlier, simpler fossils in the deeper, older rock layers and recent, more
complex fossils in the upper, more recent rock layers
this indicates the order of evolution
the age of fossils is determined from the age of the rock they’re in
older rock strata have less biodiversity which shows that there was an increase in biodiversity
over time
the fossil record contributes to the compilation of a geological time scale from the origin of the
earth until now
the geological time scale shows the increase in complexity over time (prokaryotes to more
diverse)
, The fossil record has many gaps, especially when changing from one organism to
another
Fossils of transitional types are very rare
Archaeopteryx is an example of a transitional fossil
it is known as the earliest and most primitive bird
’It is thetransition between reptiles and birds from the Jurrassic period (150mya) and has bird
and reptile characteristics
Evolutionary scientists like Stephen Jay Gould
and Niles Eldridge have formulated alternative
theories to explain the gaps in the fossil records
MODIFICATION BY DESCENT
the basic body plans of different plant and animal groups were modified to adapt to their
different environments
this phenomenon is known as modification by descent and it provides evidence of evolution
MODIFICATION IN VERTEBRATES:
the forelimbs of various vertebrates like amphibians, reptiles, birds and mammals look different
and perform different functions, but show the same basic body plan
functions include digging, flying, running, swimming and climbing
the basic body plan consists of the following bones:
1. one proximal longbone (humeris)
2. two distal bones (radius and ulna)
3. number of wristbones (carpals)
4. five metacarpals that form the palm
5. phalanges (fingers)
pentacactyl limb= 5 digits (fingers)
similar structures (eg forelimbs) with the same body plan that perform different functions are
known as homologous structures
They show evidence of evolution because similarities may trace to a common ancestor
the changes/adaptations happenindependently in each group according to habitat and mode of
life
, different evolutionary paths Analogous structures- same
common ancestor structures with same function
but no common ancestor
MODIFICATION WITHIN A SPECIES
according to this theory, many species changed over millions of years to form the species we
know today
these modern species are modified descents of earlier species
adaptations/modificiation occurred to adapt to different environments
the evolution of the horse is an example:
