Midterm 2 Flashcards
What is human-mediated evolution?
Evolution which occurs as a result of human activities.
What is artificial selection?
Rapid changes in a population of domestic animal or plants through breeding for select traits.
What is traditional breeding?
Traditional breeding is the selection for pre-existing traits in a species. Intentional activity where organisms with perceived beneficial traits are bred and organisms which don’t have those traits are not allowed to reproduce (plant breeding, animal husbandry).
What is genetic engineering?
Genetic engineering is the intentional transformation of the genome.
What is taming?
Conditioned behavior in a wild-born animal involving reducing is natural avoidance response to humans.
What is domestication?
Phenomenon where one organism assume responsibility for the care and reproduction of the second organism.
What is population sire effect?
It’s the over representation of certain genes in the next generation due to the over breeding of an animal with superior traits.
Over time, offspring from this animal may make up a disproportionately large proportion of the next generation, and so its negative traits, which might lead in a population bottleneck.
What is agrobacterium tumefaciens?
A parasitic species of bacteria that can insert the DNA of its plasmid into plant host and it’s now used to do genetic engineering.
What is CRISPR/Cas9
A natural immune system against viruses and pathogenic plasmids in prokaryotes. It destroys viral DNA by cutting DNA strand. Modified, it allows us to specifically choose which genes to cut out and which genes to insert in the organism.
What is gene drive technology?
During sexual reproduction, an organism equipped with CRISPR/Cas9 could potentially see the CRISPR/Cas9 system modifying the DNA of BOTH parents as the embryo develops.
How have humans practiced artificial selection?
By plant breeding and animal husbandry.
In what way can we used CRISPR/Cas9 to affect other species?
- Resisting pathogenes
- Limiting fertility in invasive species
- Increasing fertility in endangered species
- Destroying population
How novel gene-editing technologies can direct evolution?
By mixing genes in different species.
What kind of selection is traditional breeding?
Directional selection because breeding attempts are generally focusing on a single trait.
What are the desirable traits in animal husbandry?
- Harvestable commodity
- Ability to be domesticated
- Useful role
- High fecundity
What are the limitation of traditional breeding?
- The pre-existing genes in a species
2. The number of other species that could hybridize
What is the big revolutionary thing about genetic engineering?
Possibility to combine desirable genes of two different species that could never naturally breed.
What is the big revolutionary thing about genetic engineering?
Possibility to combine desirable genes of two different species that could never naturally breed.
What are the big problems with A. tumefaciens?
- There is no control over where the bacteria inserts it’s DNA into the genome of the host.
- You can’t insert bacterial DNA into a fully mature plant.
- To transform al the cells of a plant, you need to develop an embryo on a artificial growth media, which is itself costly and take long studies to develop.
How do you test to see whether the DNA has inserted into the correct position with A tumefaciens?
You need to test each and every plant (long and costly).
What are the desirable traits in commercial flowers?
- Herbicide tolerance
- Pest and disease resistance
- Comercial compounds
- Flower color
- Longer flower life
- Longer shelf life
- Better nutrition
What are the big advantage with CRISPR/Cas 9?
- Specifically choose which genes to cut out and where to put it in the organism.
- Less costly and time consuming
- Guarantees that the trait will be inherited because CRISPR in one parent can modify the genes of the other parent in the developing embryo. (gene drive technology)
On what should editing of human embryos should be limited?
On eliminating genetic diseases.
Why is New Zealand one of the countries most severely impacted by invasive species?
Because it’s an island nation with naïve fauna that has stable temperate environment and different habitats (alpine mountains to lowland forests).
What are the unintended consequences of human activity on the evolution of other species?
- Pollution: tolerance to pollution
- Founder effect: Introduction of invasive species through small founding population
- Population bottlenecks: Population loss in native species
- Artificial landscapes: Modifying behavior because of artificial landscapes
- Pesticides: Resistance genes in weed plants and insect species agains pesticide
- Antibiotics: Mutation and spread of antibiotic resistance genes.
- Failed biological control
- Unintended natural selection: our activities can increase genes in the gene pool which would otherwise decrease fitness
Something to remember about human drive evolution
Same pattern but much faster than natural evolution because high selection pressure
Do artificial selection follow traditional evolution?
No. Specific traits are selected for artificially in a population, mutations are not random.
What are introduced /non-native/ exotic species?
A species which has been introduced to an habitat that it has not historically been found in.
What is a negative impact?
Any impact on environment which reduces/degrades:
- species diversity
- total number of individual organisms
- physical environment
What is a novel environment?
An environment a species has never inhabited before.
What is genetic pollution?
When a native species experience excessive hybridization with an introduced species.
What is an invasive species?
An introduced species which is having a negative impact on the novel environment it is in. (CAN’T BE A NATIVE SPECIES ENVEN IF IT HARM THEIR ENVIRONMENT).
What is the invasion potential?
The ability of a species to become an invasive species in a novel habitat (based on anthropocentric values).
What defines establishment?
- Survival
2. Successful reproduction
What are the characteristics that an environment that has great number of introduced species tends to have?
- Warm
- Consistent rainfall
- Stable weather
What is the lag phase?
The period of time when a newly established species must increase in number before starting to spread.
What are the waves of introduction?
Other individuals of the same species brought to the novel habit which allow gene flow between source and founder populations.
Can impact phase overlap with spread phase?
Yes
What are the general traits associated with greater invasion potential?
- High fecundity
- Asexual reproduction
- Generalist in habitat preference and food need
- Defensive/hunting strategies not found to the novel environment
What is propagule pressure?
Measure of the number of individuals of a species released into a region to which they are not native
What is prey naiveté?
When a prey species has no defensive response to a predator species.
What is predator release?
When a introduced species is found in a novel environment where few or no species hunt it.
What are the factors in the novel environment that helps survival of invasive species?
- Prey naiveté
- Predator release
- Open niches
Define biodiversity.
Many different species and types of species.
So in what can we measure the invasiveness of a species?
- Trait of the introduced species
2. Characteristics of the novel environment.
What is invasion meltdown?
Where and invasive species negatively impacts multiple native species both directly, and indirectly by modifying the abiotic environment.
What is biological control?
The intentional introduction of a non-native species to control another (usually non-native) species.
What are the changes in the novel habit that invasive species can bring?
- Selection pressure on native species (evolution of prey response, behavior)
- Ecosytem and abiotic effects
What are the changes in the novel habit that invasive species can bring?
- Selection pressure on native species (evolution of prey response, behavior)
- Ecosytem and abiotic effects (often through the loss of another species)
What are the two classes of intentional introductions?
- Biological control
2. Intentional for human use