Genomes to Ecosystems Flashcards
(98 cards)
1
Q
What makes corals turn white and become bleached
A
When they expel there symbionts that give coral its tan colour, they appear white.
2
Q
Why does coral expel its symbiont and why is this such a large issue?
A
When temperature and light go up, the photosystems in the dinoflagellate break. The rain of photons doesn’t stop however and that energy is turned into reactive oxygen species that damages the coral. In response to this, the coral kicks out the dinoflagellate, which provides 75-90% of its energy, making the coral white.
3
Q
Why is coral bleaching such an issue in islands like the Maldives?
A
Coral grows in shallow water and can act as a wave breaker for islands, slowing down the water before it reaches the shore.
4
Q
Why is coral so sensitive to global warming and increased CO2 emissions?
A
Shallow water, where coral lives, heats up much faster than deep water. So when temperatures rise, the water quickly does as well. When there is a lot of carbon dioxide in the air, it can dissolve into water and raises acidity levels in the water. This increased acidity reduces the availability of of carbonate ions which coral usually combines with calcium to build its skeleton.
5
Q
What is the difference between facultative and obligate endosymbiosis?
A
Endosymbiosis is a relationship where one organism lives inside another. Obligate endosymbiosis is when the organisms or an organism needs the host to survive. Facultative endosymbiosis is when both species can live independently.
6
Q
What are some examples of human driven stressors to coral?
A
CO2 emissions and climate change cause sea surface temperatures to rise and less carbonate for coral skeleton
Ozone depletion increases solar irradiance which breaks photosystems
Deforestation - more carbon in atmosphere and soil erosion can end up in coral reefs.
Deep sea fishing can cause a prey overabundance e.g. too much algae.
7
Q
How can coral act as a carbon sink?
A
Coral takes carbon from the atmosphere and fixes it into its skeleton. The oxygen it breathes out is negated by the dinoflagellates.
8
Q
What ecosystem services do coral reefs provide for humans?
A
- Tourism
- Costal protection (wave break
- Carbon sinks
- Habitats for fisheries
- Drug discovery
- Biodiversity
9
Q
What mechanisms can be used to try conserve coral reefs?
A
- Protection of coral reef
- Awareness campaigns to bring this issue to light
- Coral gardening to replant coral in damaged reefs
3a. Genetic selection- purposely selecting coral that survives in artificially harsh environments - Finding more robust dinoflagellate e.g. from hotter areas and introducing them to coral. The coral must be flexible and not selective for this to work.
10
Q
What is an ecosystem?
A
An ecosystem is the biological community living in an area (biota) plus the physical, chemical and climatological conditions that make up its abiotic environment and the interactions between these.
11
Q
What are the primary ecosystem processes?
A
Energy transfer- energy is captured from the sun and transferred into the ecosystem (external source).
Nutrients, water and CO2 cycling- come from within the ecosystem and are cycled from form to form by the ecosystem processes
12
Q
What are ecosystem processes and what are some examples?
A
Ecosystem processes are the mechanisms that the primary ecosystem processes rely on e.g. photosynthesis, decomposition, predation
13
Q
What is the meaning of ecosystem functioning?
A
The capacity of ecosystems to carry out the primary ecosystem processes.
14
Q
What are ecosystem goods and services and why are they important?
A
The benefits the ecosystem provides for humans. In the past humans undervalued ecosystems and destroyed them. Ecosystems don’t replenish quickly so this puts a monetary value on ecosystems to encourage protection to governments
15
Q
What is the difference between supporting services and ecosystem processes?
A
Supporting services are the ecosystem processes necessary to produce all other ecosystem services, such as regulating and cultural services.
Ecosystem processes are the mechanisms that contribute to ecosystem functions.
16
Q
What are all the ecosystem goods and services?
A
- Supporting services: necessary for all ecosystem services
- Regulating services: help regulate and maintain the environment and natural phenomena
- Provisioning services and goods- the material benefits we gain from an ecosystem e.g. food, water, wood, medicine
- Cultural services- nonmaterial benefits people gain from ecosystems such as cognitive development, spiritual enrichment, reflection and recreation.
17
Q
Why is the ecosystem unable to support many tertiary animals?
A
Energy flow through the ecosystem results in a lot of energy lost at each stage or transfer e.g. primary to secondary consumers etc.
18
Q
What first highlighted the value of ecosystems and their services?
A
The global Millennium Ecosystem Assessment initiative which was launched by the united nations in 2000. It revealed that 2/3 of the earths ecosystems were in decline or threatened.
19
Q
What is meant by pattern in evolutionary sense?
A
Pattern is the change we see in the fossil record overtime. It is like the phenotypic change in species over time.
20
Q
Why is understanding pattern important?
A
It allows us to infer evolutionary relationships between fossil organisms and living descendants, and helps us reconstruct evolutionary change and figure out who is related to who.
21
Q
What are the early theories of evolution?
A
Scalae naturae: All organisms are on a steady march towards perfection, starting with slime moulds at the bottom and humans at the top
Theistic evolution: Devine being created all beings along time ago. It can also be the belief that a god drives beneficial mutations
Orthogenesis: Organisms evolve in a straight line, selection pressure towards a specific goal.
22
Q
What are the more recent theories of evolution and how do they have some truth in them?
A
Catastrophism: theorises evolution is driven by catastrophic events- catastrophic events are significant to evolution
Lamarkism: Organisms acquire traits through their lifetime that are heritable- epigenetics are somewhat similar to this
Mutationalism is the theory that species emerge in large jumps due to mutations- mutations do cause evolution but much more slowly
23
Q
What is Darwin’s thinking and theory of evolution
A
All species are fertile enough that if all offspring survived and reproduced, the population size would grow, but populations stay relatively stable. Resource availability is limited and tends to stay relatively stable, so there must be a fight for survival. There is a variety of traits within a species that are heritable. Species with more advantageous traits are more likely to survive and reproduce passing on these traits to the offspring. These variations accumulate over time to form new species.
24
Q
How did Mendel contribute to modern synthesis
A
Mendel came up with two key rules of inheritance.
1. Law of segregation: genetic material is split into gametes
2. Law of independent assortment: genetic material is a mix of maternal and paternal DNA
25
What are the different types of selection?
Stabilizing selection selects against both extremes and favors the mean
Directional selection selects for one of the extreme and against the other
Disruptive selection selects against the mean
26
What contributes to the phenotype of an individual and how is this beneficial?
There are genetic and environmental aspects to every trait. This allows organisms to adapt to their environment. This is known as phenotype plasticity: variation across the same genetic background. Only the genetic aspect is heritable.
27
What is the heritability of a trait and how can this be calculated?
The heritability of a trait is how much of that trait is due to genetic factors- how much of the trait can be inherited. It is the ratio of genetic variation over phenotypic variation (h2= Vg/Vp). A good way to measure heritability is to plot the mean value of a parental pair trait to the mean value of a offspring trait on a graph and measure gradient.
28
What is the breeders equation?
The breeders equation is used to determine the change in phenotypes between generations by taking how much phenotypic change there has been due to selection and multiplying it by how much of that change will be heritable.
R= h2S
If the heritability is one, then the change in phenotype will be perfectly inherited.
29
What is sexual selection?
Genes that improve chances of finding a mate are selected for and more likely to be passed onto the next generation.
30
What is the difference between intrasexual selection and intersexual selection?
Intrasexual selection is when there is competition within the same species for access to mates (male dominance)
Intersexual selection is where members of one species choose members of the opposite sex based on traits that show fitness.
The sex that chooses the mate may be to do with investment they make to offspring
31
How does sexual selection affect variability in reproductive success?
The species that is being selected has much more variation in reproductive success. e.g. females selecting males based on traits: most females have similar reproductive success but a lot of variation in the males.
32
What is phylogeny?
The evolutionary history of a species of group, often represented by a phylogenic tree
33
What is comparative anatomy?
Comparing similarities in the anatomical structures of organisms, organisms that look similar are likely to have a common ancestor.
34
Why is the fossil record so important?
The fossil record shows how species have evolved and how different species are related to each other. Fossil evidence can be used to bridge the gap between different species.
35
What is the use of molecular clocks and how do they work?
Molecular clocks are used to estimate how long ago species diverged. Regions of DNA evolve at a fairly constant rate so by measuring the differences in the genetic sequences of species, how long ago they diverged can be estimated.
E.g. how many mutations happen per generation and how long generation time is.
36
Where do the different types of DNA get inherited from?
Children get 50% of their nuclear DNA from each parent, 100% of their mitochondrial DNA from the mother and 100% of their y chromosomal DNA from their father.
37
How recently did humans and Neanderthals' co-exist?
30000 y/a
38
Where did all the similar human species live 100000 years ago and 25000 years ago
Homo-sapiens: africa
Homo-neanderthalensis: europe
Home-erectus: asia
25000 homo-sapiens were the only species on the planet.
39
Why do we have 3-4% of neanderthal DNA in our genome?
Humans and neanderthals genetically split around 700000 years ago, and were different species living in different areas 370000 years ago. Modern humans then spread from africa and reached europe 40000 years ago where they met neanderthals again and reproduced.
40
Why is there more variation in chimps that humans?
There is more variation in chimps than humans even though human population size is much larger. Chimps population size has been more stable over a much longer period of time, where as human population size has grown rapidly. Humans have the amount of variation expected in a much smaller population, but with time it will get more diverse.
41
How did oetzi the iceman die and how was his discovery impactful?
Oetzi the icemans remains were found in the italian alps in a glacier. DNA evidence suggests he died 5300 years ago. He was thought to have died from exposure to cold but an arrowhead was found lodged in his back. Oezti is the only organic material from the copper age to exist.
42
Why are caves a useful resource in evolution?
Caves are very dry, DNA in caves can be preserved and studied to see where animals lived across history. They cannot support organisms as they are too dry.
43
What are the limitations of DNA sequencing to find ancestry?
DNA sequencing shows a range of similarity rather than an exact similarity meaning finding distance relatives is not very accurate
44
What is tristan du cuhna and what is this an example of?
Tristan du Cuhna is the most isolated population on earth, and has a population of 264 people from 15 ancestors. There are seven surnames on the island. This is an example of the founders effect- a very small subset from a large population that has become isolated, resulting in a reduction in genetic diversity.
45
How were Y chromosomes used on tristan du cuhna to track ancestors and what does this uncover?
Y chromosomes dont change much between generations so they were used to track ancestry. Nine Y chromsomes were found on the island, 7 from the surnames and 2 from visitors.
46
How is this population important to understand rare conditions?
The tristan du cuhna population can help us understand the genetics of rare conditions as they appear proportionately high in these populations. 25% of the island have asthma as atleast 3 of the ancestors had it.
47
What is a species?
A species is a population of organisms in which any two individuals of the appropriate sexes can reproduce and create fertile offspring. Individuals in a species may not be very similar but they will always be more closely related to each other than to any other species.
48
What is allopatric speciation and how can this create new organisms?
Allopatric speciation occurs when an external barrier separates a population causing a population to become isolated from each other. Populations that aren't breeding diverge genetically and become unable to interbreed. Founders affect is when a small subset of a population is isolated from the main population. This results in rapid evolution due to a non-proportionate sample of genes.
49
What is sympatric speciation?
When populations become isolated but not by a geographical barrier. Populations start to differ in habit or behaviour or adaptation. Preferential mating may lead to new species being formed.
50
What is adaptive radiation?
Adaptive radiation is when there is many new species arising at once due to key innovations, environmental changes or ecological changes. These allow the species to diversify and fill different niches.
51
Describe how development of the swim bladder led to a radiation in bony fish?
The swim bladder was a key innovation in bony fish. It is a gas filled organ that allows them to control buoyancy in the water. This allows fish to stay at a depth without exerting energy and has led increased variation in fish shape as they do not need to be a certain shape to float and survive. Sharks have no swim bladder, so have to keep swimming all the time to stay buoyant and have to be streamlined.
52
Describe how development of the jaw structure led to a radiation in bony fish?
Many bony fish have a kinetic skull has many moving parts including more dynamic jaws. This development in jaw structure has allowed for adaptations such as the upper and lower jaw moving to allow a fish to open its mouth wider or a second set of jaws (pharyngeal jaws) which allow the fish to pull its prey in after it has it in the grasp of its mouth.
53
How can environmental changes lead to radiations?
When organisms move to new habitats, specifically islands, they tend to change size. Large animals become small due to lack of resources and small animals become large to avoid being predated (e.g. Komodo dragon, giant tortoises)
54
What factors lead to the Cambrian explosion?
The Cambrian explosion was a massive boom of new animals around 530,000 years ago. This was documented through the fossil record with many weird creatures in nearly all animal phyla. This radiation was to do with environmental changes: increase in earth oxygen and end of snowball earth, Developmental changes: two copies of the genome, and ecological changes: evolution of eyes leading to predation, leading to an arms race between predators and prey
55
How many mass extinctions have there been and what normally causes them?
There have been 5 major extinctions: Ordovician-Silurian, Late Devonian, Permian, Triassic-Jurassic, Cretaceous-Tertiary. Mass extinctions normally happen because of a major catastrophic event such as a meteor impact.
56
Why are mass extinctions so important?
Mass extinctions have a massive impact on the tree of life, these extinctions wipe out between 75% and 96% if species.
57
What is the Anthropocene extinction?
The Anthropocene extinction is happening right now, it is driven by humans and is characterized by the loss of large animals.
58
What is driving the Anthropocene extinction?
There are multiple ideas of why this may be happening-
- Humans are overhunting megaherbivores causing the extinction of predators as well.
- Climate change after the ice age may have led to animal extinctions
- Disease from humans or other animals
-Second order predation, humans kill predators leading to an overpopulation of prey and a ecosystem collapse.
59
Why is the Anthropocene extinction thought to be associated with humans?
The time humans arrive on a continent and the time of major large animal extinctions seem to align. Large animals in remote areas survived until more recently e.g. most megafauna went extinct by 12000 years bp, but mammoths were alive on St. Paul 6500 years bp.
60
How are humans able to bring mammoths back and why are we not?
Mammoths remains have been discovered with fully intact DNA, and have a very similar genome to elephants. Its is possible to create a mammoth elephant hybrid by splicing mammoth genes into an elephant embryo. There is a lot of ethical concerns around this and elephants are social creatures but there is not parents to raise the mammoth.
61
What are the three levels of ecosystem organization?
1. Individual: One organism by itself
2. Population: a group of organisms from the same species, living in the same area. There is some variation between these organisms but they are all still the same species.
3. A community is multiple populations living in the same environment. All the species share the same resources and habitat.
62
How can populations be separated?
Populations can be separated geographically, or can be separated behaviorally. For example, different orca populations come into contact with each other but don't interbreed because of hierarchical reasons in the group.
63
Why can an area only support a limited amount of individuals.
Each organism has key biological processes needed for survival such as metabolism, growth, thermoregulation, activity, reproduction. Organisms have to rely on the limited amount of resources in the ecosystem to full these.
64
What is the most energy intensive individual process?
It depends on the species, in humans basal metabolism is the most energy intensive, in penguins, activity is and in deer mouse in temperate north America thermoregulation is. Reproduction is especially costly but is crucial to the survival of populations. The larger the litter of the organism, the higher the energy costs. If the organism lays eggs, there is less energy cost. The smaller the organism the more energy needed for thermoregulation.
65
What is primary succession?
Primary succession is the process of going from a bare inorganic matter to a biodiverse ecosystem. This may occur when there is emergence of new bare land such as an earthquake causing emergence of an island (Pakistan)
66
What is the process of primary succession?
1. Initiation: bare inorganic matter
2. Colonization: low-nutrient, low water unstable soil. Lichens begin to turn inorganic matter into organic
3. Development: Stable soil, the land can support small annual plants and grasses.
4. Mature: Stable, nutrient and water rich soil: Competitive bushes and small trees begin to grow
5. Climax: Stable, nutrient and water rich soil: Large trees can grow. Many resources.
67
What is secondary succession?
Secondary succession occurs when there is destruction of a previously biodiverse area, for example deforestation or wildfires. It is the reestablishment of the biodiverse landscape.
68
What are population controls and what types of this are there?
Population controls are the factors that limit population size. These can be density independent meaning the effect all species in an environment e.g. harsh weather, or density independent meaning they effect affect certain species in the environment, depending on population size e.g. intraspecies competition.
69
What type of population control are stressors and how can species adapt to this?
Stressors are density independent factors, they are changes in the environment that effect all species in an area. Species may disperse in response to this- they leave there habitat to try find better resources or conditions- but this is a risk due to energy investment, predation and lack of suitable settlement. Migration is similar to dispersal but it is predetermined and happens seasonally- to the same area. Less risky.
70
What is the carrying capacity of a population and how do species react to this?
The carrying capacity is the number of individuals an environment can sustain. With no density dependent factors e.g. unlimited resources species would exponentially grow. Some species are not sensitive to their environment so will grow passed the capacity and then die off. Some species are sensitive to the environment so will fluctuate below the capacity but never reach it.
71
What is competition?
Competition is organisms competing for the same resources. This can be within species or between species.
72
What are the consequences of competition?
When two populations are competing, one will outcompete the other and exclude it. This leads to co-existence where they differentiate their ecological niches, or keep competing until one species is eliminated.
73
How does co-existence occur and what is an example of this?
When species compete, the more dominant species gets access to preferred habitats and resources, and the subordinate competitor is left with the remaining suboptimal habitat and resources. Two barnacle species compete for the lower area on the rock as this allows for more time underwater when the tide comes in allowing longer access to the food source. Balanus is the dominant species so gets the low area of the rock, while Chthamalus is the sub-ordinate species and gets the higher area of the rock.
74
What are fundamental and realized niches
The fundamental niche is the set of resources and conditions which a species could survive under, whereas the realized niche is the set of resources and conditions where a group of organisms actually survive.
75
In reference to niches, how do invasive species effect the ecosystem?
Invasive species outcompete native species, due to a lack of predators or controls, and force them into a sub-optimal realized niche.
76
What are some examples of niches used by organisms?
Parasites use the host as its niche, similar species, such as warblers, that live in the same area develop different realized niches to avoid competition. Darwin's finches developed different traits based on the available realised niches on different islands.
77
How can temporal variation impact species co-existence?
Predictable changes over time like seasons create different conditions that various species exploit- animals such as arctic terns can follow food availability- abundance of fish in southern ocean over winter.
78
Which groups are the most prone to migration and give some examples of migrating species for different reasons?
There is no specific group most prone to migration, herbivores however tend to be the most likely group to migrate. Some examples of migrating species include-
The monarch butterfly move after the milkweed plant- their primary food as caterpillars, they move south in the winter to Mexico as temperature is milder.
Bluefin tuna move depending on their stage in life- juveniles go to safer area.
Leatherback turtles go to the beach to law eggs.
Zebras migrate to follow the availability of grass and follow the same pattern despite cattle fencing.
79
How do populations of the same species differ in migration?
Different populations within a species may have their own niche of migration. They may follow different routes and go to different places.
80
What are the advantages of migration?
1. Animals can exploit new resources that become available with seasonal change
2. Animals can protect vulnerable young by taking them to a safer area
3. Animals can avoid inbreeding depression by breeding with different migrating populations. Animals may also migrate to find mates.
4. There is reduced competition when animals move away from an area for the migrating species and the local.
81
What are some disadvantages of migration?
Migration can be risky-
1. Bad weather can put animals at risk and disorientate animals, there may not be places to stop or they may have limited resources
2. Some animals may take advantage of migration to hunt and get food (elonars falcon)
3. Animals may be confused by artificial light from cities and become disorientated, or human infostructure can block migrating animals
4. Final destination may have changed dramatically over the year- no recourses to replenish energy.
82
How can migration of species be tracked and studied and what are their limitations?
1. Point counts- counting animals from a single point as they fly by, not that accurate as animals may be counted twice and there is no indication of where animals are going
2. Markings- Animals may have natural marks or may be given artificial ones to ID them (e.g. bird rings), can track upon recapture.
3. GPS tags can be fitted onto animals- these tags can track the exact movements of an organism and are temporary so will fall off. Radio telemetry can track animals via radio receivers.
4. Radar can be used to track large groups of birds but you cannot identify specific species.
83
How does spatial variation in an ecosystem encourage co-existence.
Diverse environments with many habitats and recourses allow support to many species and allow species to specialize and coexist by providing many niches. Coral varies in light level, depth and disturbance frequency so can support many species.
84
What is an assemblage?
A subset of a community with a defined interaction, like predators and prey.
85
What is biomechanics?
The study of the structure, function and motion of the mechanical parts of an organism.
86
What are examples of biomechanical changes to an animal for migration?
1. Wing shape in birds and butterflies: There is a relationship between wing size and maximum migration distance. The shape of the wing may also change if they migrate. Migrating birds, such as the albatross, tend to have narrow tapered wings to reduce drag.
2. Aquatic animals may have streamlined bodies to avoid drag during migration and increase swimming efficiency
87
What are example of physiological changes to an animal for migration?
1. Fuel source: migrating animals often heavily rely on fatty acids as an energy source, this provides more energy per unit weight than carbs and can allow animals to travel long distances without having to refuel.
2. Organ size change: migrating animals may have a different body composition with larger muscles, hearts and lungs and smaller digestive organs like the stomach and kidneys.
3. Specialized diets: some animals only eat food sources rich in particular nutrients to support migration. An example of this is the semipalmated sandpiper eats shrimps rich in fatty acids before embarking on nonstop flight.
88
How can human activities effect migration?
1. Humans may hunt migrating species significantly lowering their numbers (passenger pigeon)
2. Habitat loss and fragmentation: human infostructure can disrupt migration routes and may destroy crucial stopovers or breeding grounds
3. Light pollution: artificial light from cities may confuse animals when they think they are following the moon. E.g. birds and sea turtles.
4. Climate change can alter the timing of resource availability, leading to mismatches between arrival and peak food availability.
89
What is environmental management?
Making decisions implementing actions to balance human needs with the protection of the environment. Developing strategies to ensure suitable use of resources. It involves compromises on each side. Environmental management aims to protect whole ecosystems rather than individual species.
90
How was land managed in the past?
The inaccessibility of areas provided protection to species living in them. Available land was not allocated very well, the oklahoma land rush is an example, where people raced to be the first to claim land.
91
How has the modern world made environmental management more important?
1. Better technology has improved accessibility around the world and uncovered new resources.
2. There is only a finite amount of resources on the planet- growing awareness of this
3. There is conflict over how to use and protect the environment
4. Evidence of environmental degradation has highlighted the need for effective management
92
What is the tragedy of the commons?
Economic theory which shows how resources can be depleted when people act in their own self interest. One person over farming can share the burden across the whole group- e.g. antibiotic use as short term gain but antibiotic resistance, fishing in a pool till fish cannot breed.
93
What are the limitations of species based management?
A conservational approach that focuses on the management of a single (at risk) species. This led to endangered species act. This approach overlooks less charismatic species or the interconnectedness of the whole ecosystem.
94
What are the limitations of community based management?
This approach empowers local communities to use resources sustainably. It involves practices that are effective when there is a strong connection between the community and the resource. For example indigenous fishing communities around the world. This is difficult to scale up to larger areas or manage resources that are not used locally.
95
Why is ecosystem management the best strategy?
Ecosystem management focuses on whole ecosystems. It recognizes the interconnectedness of different components of an ecosystem.
96
What is the process of passing environmental legislation?
It first involves directives being set out at international meetings. The directive goes to devolved governments. The governments interpret the initiative and get inputs from consultees, such as the general public and stakeholders, and from statutory consultancies such as nature scot who provide expert advice on environmental matters. Once the law becomes national policy, the government then must work out what areas come under this legislation.
97
What are marine protected spaces and what challenges may they face?
Marine protected spaces are essential tools for managing marine biodiversity, and ensuring sustainable use of marine resources. Establishment of these may be challenging because:
- Gathering sufficient data on marine ecosystems can be difficult and costly
- Balancing the needs of stakeholders and conservation can be difficult
- Monitoring and enforcing regulations in the vast marine environment can be challenging
98
How can artificial intelligence effect the environment?
Artificial intelligence needs vast servers which have huge energy demands. Need to focus on the ethical concerns but also the environment.
