Samenvatting evolutiebiologie
Niko Tinbergen 4 questions:
-Mechanism, what is it for?
-Evolution, how did it evolve over the history of the species?
-Development, how did it develop during the lifetime of the individual?
-Function, how does it work?
Theodosius Dobzhansky ones said: “Nothing in biology makes sense except in the
light of evolution”. Evolution is the guiding principle of Biology.
We humans have a impact of the evolution of several animals, for example fish.
Because of selective harvesting on big fish, it is better for the fishes in the see to
be smaller. Smaller fish tend to survive the selective harvesting of humans. And
also the hatchery (broeden) of fish will make the ecosystem loses its balance.
Therefor the evolution of fish is forced by human.
An evolutionary impact assessment (EIA) is a scientific framework used to
measure and quantify how human harvesting (such as hunting, fishing, and
logging) causes evolutionary changes in populations.
This figure shows how natural mortality and
fishing mortality exert selection pressure on
fish size, which can lead to evolutionary
changes in fish populations.
Small fish have a high natural mortality (due
to predation, disease, competition). As fish
grow larger, their natural mortality decreases
significantly. Large fish therefore have fewer
natural enemies and a greater chance of
survival.
But because of fishery there also is an
selection gradient towards the other side. Fisheries usually target the largest
,individuals. This can be seen in the sharp increase in mortality at a certain fish
size. This creates a new selection pressure: fish that grow too large have a
greater chance of being caught and therefore die sooner. The green line don’t
even gets to the most left of the graphic because small fish can’t be caught right
now.
When population reduce in number, this is very bad for the population. Because
the animals are forced to inbreeding. Because of inbreeding the population will
have almost no genetic variation in there immune systems. Take the example
where the cheetah did not recognize the donor tissue as non-self.
Inbreeding makes animals less able to adapt to changing environments or new
damage.
Evolutionary biology are used to conversation biology, this is the biology where
humans try to protect nature, species and ecosystems. They try to protect nature
by:
1. The identification of evolutionary significant units (ESU). ESUs are
populations within species that are genetically and evolutionarily unique
and should be protected separately. The loss of an ESU represents an
irreversible loss of sufficient diversity, which may reduce the survival
chances of the species as a whole.
2. Avoidance of inbreeding in captivity. Inbreeding can lead to reduced
fitness.
3. Avoiding the loss of adaptive variation (adaptive rescue). Adaptive
variation is genetic traits that help a population adapt to changes in the
environment. Adaptive rescue means that we maintain or enhance genetic
diversity to help a species survive.
4. Identification of minimal population size for viability. This involves
determining the minimum population size needed for a species to survive
long term.
5. Predicting the response to global change. Evolutionary biology helps
predict how species will respond to climate change, habitat loss, and other
environmental challenges.
An other verry important evolution study is the evolution of pathogens and
antibiotic resistance. Pathogens evaluate verry quickly what leads to new
variants of the virus and resistance of an antivirus or medicine.
Evolutionary biology helps understand, predict and combat infectious diseases
such as COVID-19, by:
-To analyse mutations and evolution of viruses.
-To investigate genetic causes of disease differences.
-To map the spread of infections worldwide.
-To evaluate the long-term effectiveness of vaccines and treatments.
It is important to understand that it is not because of an antibiotic that there is a
bacteria that becomes resistant. There are already bacteria with a random
mutation what makes them resistant against the antibiotic. Because they are the
,fittest, because they survive the antibiotic they will reproduce. More and more
bacteria will have the mutation that makes them resistant against the antibiotic.
Evolutionary consequence of very large populations: ? Let’s take Covid-19 for an
example. Because of the many individuals who were infected by the virus the
viral load was high, so there were very much viral cells. The virus could multiply
in millions of people and therefor the virus had many mutations. This is a large
opportunity for evolution. Because the virus whit the best spontaneous mutation
would survive.
Because of the millions of people who were infected, the virus had millions of
possible mutations already and therefor the options of several possible COVID-19
variations yet to come is small. We have already seen them all.
We also use evolution in agriculture and domestication. We improve crop and
livestock by selective breeding. Domestication means the process by which wild
animals or plants are adapted and trained by humans to live and function in a
domestic environment. Think of you dog.
What is evolution:
1. Descents whit modification: This means that current species come from
earlier ancestors, but with changes (modifications) in their characteristics
over time.
2. Changes in the properties of populations that transcend the
lifetime of a single individual: An individual can adapt to its
environment during its lifetime, but evolution only occurs when these
changes are heritable and spread over several generations.
3. Changes in allele frequencies over time: Evolution means that the
frequency of certain alleles (genetic variations) in a population can change
through natural selection, genetic drift, mutations or gene flow.
If we map out the hight of students in a population against
the average hight of both parents we see a positive line. This
confirms that offspring resemble parents and that traits are
heritable.
History:
Aristotle considered living beings to be divided into a
gradation of perfection. This existing that:
Plants were ranked because they are alive but have no
senses. Animals were ranked above them because they
could move and perceive. Humans were ranked at the top because of their
intellect and rational thinking.
Linnaeus started to group organisms based of similarity, this he did in his book
Systema Naturae. He began the modern system of taxonomy in an attempt to
discover order in the diversity of life. He started the hierarchical relationships of
organisms. Kingdom-Phylum-Class-Order-Family-Genus-Species.
, After that Lamarck had the first evolutionary theory.
Lamarck believed that simple life forms continually arose spontaneously from
inanimate matter. This meant that nature was constantly producing new
organisms, without the need for a parent organism. If a species seemed to
disappear, it simply meant that it had changed into a new species. Species were
not related by descent, but each organism moved independently up the ladder of
evolution.
The "nervous fluid" would be the force that propels living things to move up this
ladder, suggesting that there was some kind of "purposeful" progress in
evolution, rather than evolution being random or driven by natural selection.
But there were a few problems with his idea:
- There is no evidence of spontaneous generation and plenty for extinction
- There is no evidence of an innate drive toward complexity
- There is no evidence of inheritance of acquired characteristics. Changes in
genes (through mutations) can be passed on to offspring, but changes in an
individual's physical characteristics that are not genetic (such as a muscle that
grows stronger with exercise) are not inherited.
Uniformitarianism states that:
The processes that shape the earth today are the same as those in the past.
These processes happen very slowly and gradually, in painful to painful changes
that happen abruptly and through catastrophic events.
This existing that:
The earth must be much older than men had previously thought. The geological
changes that we observe now give us insight into how the earth formed in the
past.
Charles Darwin went on a ship for 5 years and discovered for example animals
that looked alike but lived far away from each other. He discovered that recent
fossils are closely related to species that live nowadays.
He discovered that population that are physically isolated tend to differ, because
of for example different ecological settings. It was discovered that there was high
variability within a species. Variants can pass these characteristics to offspring.
Artificial selection can rapidly alter the characteristics of a breed. This is because
people choose the prettiest dogs to breed with each other so they only get the
most beautiful dogs, this artificial selection is way faster than natural selection.
In the same period of time Thomas Mathus came to the conclusion that
populations reproduce exponentially. Natural populations have a large capacity
to reproduce and if left unchecked they will increase faster than we can produce
food to feed them. He said: “ many more organisms are born than can possibly
survive”.
Darwin read the conclusions and used them whit his knowledge. And combined
with each other and came to the conclusion that under these circumstances
Niko Tinbergen 4 questions:
-Mechanism, what is it for?
-Evolution, how did it evolve over the history of the species?
-Development, how did it develop during the lifetime of the individual?
-Function, how does it work?
Theodosius Dobzhansky ones said: “Nothing in biology makes sense except in the
light of evolution”. Evolution is the guiding principle of Biology.
We humans have a impact of the evolution of several animals, for example fish.
Because of selective harvesting on big fish, it is better for the fishes in the see to
be smaller. Smaller fish tend to survive the selective harvesting of humans. And
also the hatchery (broeden) of fish will make the ecosystem loses its balance.
Therefor the evolution of fish is forced by human.
An evolutionary impact assessment (EIA) is a scientific framework used to
measure and quantify how human harvesting (such as hunting, fishing, and
logging) causes evolutionary changes in populations.
This figure shows how natural mortality and
fishing mortality exert selection pressure on
fish size, which can lead to evolutionary
changes in fish populations.
Small fish have a high natural mortality (due
to predation, disease, competition). As fish
grow larger, their natural mortality decreases
significantly. Large fish therefore have fewer
natural enemies and a greater chance of
survival.
But because of fishery there also is an
selection gradient towards the other side. Fisheries usually target the largest
,individuals. This can be seen in the sharp increase in mortality at a certain fish
size. This creates a new selection pressure: fish that grow too large have a
greater chance of being caught and therefore die sooner. The green line don’t
even gets to the most left of the graphic because small fish can’t be caught right
now.
When population reduce in number, this is very bad for the population. Because
the animals are forced to inbreeding. Because of inbreeding the population will
have almost no genetic variation in there immune systems. Take the example
where the cheetah did not recognize the donor tissue as non-self.
Inbreeding makes animals less able to adapt to changing environments or new
damage.
Evolutionary biology are used to conversation biology, this is the biology where
humans try to protect nature, species and ecosystems. They try to protect nature
by:
1. The identification of evolutionary significant units (ESU). ESUs are
populations within species that are genetically and evolutionarily unique
and should be protected separately. The loss of an ESU represents an
irreversible loss of sufficient diversity, which may reduce the survival
chances of the species as a whole.
2. Avoidance of inbreeding in captivity. Inbreeding can lead to reduced
fitness.
3. Avoiding the loss of adaptive variation (adaptive rescue). Adaptive
variation is genetic traits that help a population adapt to changes in the
environment. Adaptive rescue means that we maintain or enhance genetic
diversity to help a species survive.
4. Identification of minimal population size for viability. This involves
determining the minimum population size needed for a species to survive
long term.
5. Predicting the response to global change. Evolutionary biology helps
predict how species will respond to climate change, habitat loss, and other
environmental challenges.
An other verry important evolution study is the evolution of pathogens and
antibiotic resistance. Pathogens evaluate verry quickly what leads to new
variants of the virus and resistance of an antivirus or medicine.
Evolutionary biology helps understand, predict and combat infectious diseases
such as COVID-19, by:
-To analyse mutations and evolution of viruses.
-To investigate genetic causes of disease differences.
-To map the spread of infections worldwide.
-To evaluate the long-term effectiveness of vaccines and treatments.
It is important to understand that it is not because of an antibiotic that there is a
bacteria that becomes resistant. There are already bacteria with a random
mutation what makes them resistant against the antibiotic. Because they are the
,fittest, because they survive the antibiotic they will reproduce. More and more
bacteria will have the mutation that makes them resistant against the antibiotic.
Evolutionary consequence of very large populations: ? Let’s take Covid-19 for an
example. Because of the many individuals who were infected by the virus the
viral load was high, so there were very much viral cells. The virus could multiply
in millions of people and therefor the virus had many mutations. This is a large
opportunity for evolution. Because the virus whit the best spontaneous mutation
would survive.
Because of the millions of people who were infected, the virus had millions of
possible mutations already and therefor the options of several possible COVID-19
variations yet to come is small. We have already seen them all.
We also use evolution in agriculture and domestication. We improve crop and
livestock by selective breeding. Domestication means the process by which wild
animals or plants are adapted and trained by humans to live and function in a
domestic environment. Think of you dog.
What is evolution:
1. Descents whit modification: This means that current species come from
earlier ancestors, but with changes (modifications) in their characteristics
over time.
2. Changes in the properties of populations that transcend the
lifetime of a single individual: An individual can adapt to its
environment during its lifetime, but evolution only occurs when these
changes are heritable and spread over several generations.
3. Changes in allele frequencies over time: Evolution means that the
frequency of certain alleles (genetic variations) in a population can change
through natural selection, genetic drift, mutations or gene flow.
If we map out the hight of students in a population against
the average hight of both parents we see a positive line. This
confirms that offspring resemble parents and that traits are
heritable.
History:
Aristotle considered living beings to be divided into a
gradation of perfection. This existing that:
Plants were ranked because they are alive but have no
senses. Animals were ranked above them because they
could move and perceive. Humans were ranked at the top because of their
intellect and rational thinking.
Linnaeus started to group organisms based of similarity, this he did in his book
Systema Naturae. He began the modern system of taxonomy in an attempt to
discover order in the diversity of life. He started the hierarchical relationships of
organisms. Kingdom-Phylum-Class-Order-Family-Genus-Species.
, After that Lamarck had the first evolutionary theory.
Lamarck believed that simple life forms continually arose spontaneously from
inanimate matter. This meant that nature was constantly producing new
organisms, without the need for a parent organism. If a species seemed to
disappear, it simply meant that it had changed into a new species. Species were
not related by descent, but each organism moved independently up the ladder of
evolution.
The "nervous fluid" would be the force that propels living things to move up this
ladder, suggesting that there was some kind of "purposeful" progress in
evolution, rather than evolution being random or driven by natural selection.
But there were a few problems with his idea:
- There is no evidence of spontaneous generation and plenty for extinction
- There is no evidence of an innate drive toward complexity
- There is no evidence of inheritance of acquired characteristics. Changes in
genes (through mutations) can be passed on to offspring, but changes in an
individual's physical characteristics that are not genetic (such as a muscle that
grows stronger with exercise) are not inherited.
Uniformitarianism states that:
The processes that shape the earth today are the same as those in the past.
These processes happen very slowly and gradually, in painful to painful changes
that happen abruptly and through catastrophic events.
This existing that:
The earth must be much older than men had previously thought. The geological
changes that we observe now give us insight into how the earth formed in the
past.
Charles Darwin went on a ship for 5 years and discovered for example animals
that looked alike but lived far away from each other. He discovered that recent
fossils are closely related to species that live nowadays.
He discovered that population that are physically isolated tend to differ, because
of for example different ecological settings. It was discovered that there was high
variability within a species. Variants can pass these characteristics to offspring.
Artificial selection can rapidly alter the characteristics of a breed. This is because
people choose the prettiest dogs to breed with each other so they only get the
most beautiful dogs, this artificial selection is way faster than natural selection.
In the same period of time Thomas Mathus came to the conclusion that
populations reproduce exponentially. Natural populations have a large capacity
to reproduce and if left unchecked they will increase faster than we can produce
food to feed them. He said: “ many more organisms are born than can possibly
survive”.
Darwin read the conclusions and used them whit his knowledge. And combined
with each other and came to the conclusion that under these circumstances
