87. ARTIFICIAL SELECTION, NATURAL SELECTION & ADAPTATION Flashcards
- What is Artificial selection?
- this is the process of modification of other species by
Humans - it is done by selecting and breeding individuals with
desired traits
- Wild Mustard is a plant.
It has allowed for different vegetables to be artificially selected from it.
Name some of these vegetables.
- BRUSSEL SPROUTS
- selected for the Axillary (Side) Buds - KALE
- selected for the leaves - CABBAGE
- selected for the apical (tip) bud - BROCCOLI
- selected for the flowers and the stems - KOHLRABI
- selected for the stems
- What did Darwin propose when it comes to Natural Selection?
- he proposed that it is the mechanism
- for the evolutionary adaptation of populations
- to their environment
IT IS THE MECHANISM OF BOTH:
- descent with modification
- adaptation
- Define “Natural Selection”.
- it is a process
- in which individuals with favourable traits
- are more likely to survive and reproduce
- Define “Adaptation”.
- these are evolutionary processes
- they enhance the fitness and survival of individuals n
their environment
- Darwin drew 2 conclusions about Natural Selection and Adaptation from 2 observations.
What were these Observations?
- Variation in a Population
- Overproduction of Offspring
- What is meant by: “Variation in a Population”?
MEMBERS OF A POPULATION:
- will often vary in their inherited traits
- What is meant by: “Overproduction of Offspring”?
ALL SPECIES:
- can produce more offspring than the environment can
support
- many of these offspring will fail to survive
- this means that they have failed to reproduce as well
- Darwin drew 2 conclusions about Natural Selection and Adaptation from 2 observations.
What were these Conclusions?
- Differences in Reproductive Success
- Evolutionary Adaptations in the Population
- What is meant by: “Differences in Reproductive Success” ?
INDIVIDUALS:
- whose inherited traits give them a higher probability
of surviving and reproducing
- in a given environment
TEND:
- to leave more offspring
- than other individuals
- What is meant by: “Evolutionary Adaptations in the Population”?
THE UNEQUAL ABLITY OF INDIVIDUALS:
- to survive and reproduce
- leads to the accumulation of favourable traits
- in the population
- over successive generations
- What is closely linked to Adaptation, according to Darwin?
- adaptation to the environment
- and the origin of new species
- are closely related processes
EXAMPLE:
- the beak variations in the Galapagos Finches
- What can be seen in this image?
- beak variation in the Galapagos Finches
- their beaks differ based on their food source
- Does Natural Selection create New Traits?
- NO
- this was the ideology that existed before Darwin’s
theories disproved it
NATURAL SELECTION:
- will edit or select for traits
- these traits are already present in the population
THE INDIVIDUALS WITH THE MOST FAVOURABLE TRAITS:
- will reproduce
- they will survive
- the frequency of them in the population will increase
THE INDIVIDUALS WITH THE LEAST FAVOURABLE TRAITS:
- will die out
- they will fail to reproduce
- they will lose the battle for resources
- What is determined by the Adaptation to the Local environment?
- it determines the traits that will be selected for in any
specific population - it determines the traits that will be selected against in
any specific population - adaptations vary within different environments
- What is an example of Offspring overproduction?
- the human population
- we have the potential to increase faster than our food
supplies and other resources
- How do Natural Selection and Adaptation tie into one another?
NATURAL SELECTION:
- the advantageous heritable traits
- will accumulate in a population over time
- this increases the frequency of individuals with these
traits
NATURAL SELECTION:
- accounts for the match between organisms and their
environment
- this is known as Adaptation
- What is an example of Evolutionary Adaptation?
- Camouflage
- this is done by many insects, mammals and
amphibians
EXAMPLE:
- a mantid
- it will change colour to hide from birds
- this prevents it from being eaten
- What is an example of Natural Selection and Adaptation when it comes to human beings?
- Thalassaemia
- this can be Alpha or Beta - Sickle Cell Anaemia
- This is true for all Haemoglobin viruses
- Explain what happens with Thalassaemia, Natural Selection and Adaptation?
- those who are heterozygous carriers
- of the Thalassaemia Allele
- have a resistance to Malaria
- many of these individuals are found in countries where
the Malaria Endemic is prevalent
NATURAL SELECTION:
- favoured the selective survival of Heterozygous
carriers of the Thalassaemia allele
- What causes Malaria?
- the Plasmodium Malariae
- this is a protist
- it replicates in mosquitoes
THESE MOSQUITOES:
- live in tropical and sub-tropical regions
- they do not lie in cold and countries that are far North
- What does Plasmodium Malariae do once it enters the body?
- it infects the Red Blood Cells
- it begins to digest Haeomoglobin
- How does being a Heterozygous carrier for the Thalassaemia allele provide protection against Malaria?
- these carriers have lower haemoglobin levels
- they are more resistant to the Plasmodium Infection
since the mosquitoes will have much less interest in
them
- What is the cause of Thalassaemia being so widespread in countries where Malaria is prevalent?
- Evolution
- How is the spread of Heterozygous Thalassaemia carriers an example of Natural Selection and Adaptation
HAVING A SINGLE ALLELE FOR THALASSAEMIA:
- is an advantage
- it provides protection against Malaria in Endemic
Regions
HETEROZYGOUS CARRIERS OF THE BETA THALASSAEMIA ALLELE:
- have some protection against Coronary Heart Disease
