APES- Chapter five and 18

Niche generalists

species that live under a wide range of conditions; can live in a variety of habitats or feed on a variety of species

Niche specialists

species that only live in specific habitats; persist quite well when environmental conditions remain relatively constant, but are vulnerable to extinction if conditions change

Ecologically extinct

still there but ecologically can't do anything

Species evenness

tells the relative proportions of individuals within the different species; tells whether a particular ecosystem is numerically dominated by one species or whether all of its species have similar abundances

What are the key ideas of Darwin's theory of evolution by natural selection

-Individuals produce an excess of offspring -Not all offspring can survive -Individuals differ in their traits -Difference in traits can be passed on from parents to offspring -Differences in traits are associated with differences in the ability to survive and reproduce

Key Ideas for Ch 18

-Instrumental values are things such as food, medicine, and building materials that humans need or use. Intrinsic values provide no direct benefit to people, but follow the belief that individuals, species, and ecosystems are valuable in themselves and should be preserved -We are in the midst of a 6th mass extinction caused by humans -There has been a decline of genetic diversity in wild organisms and crops -For most species, the greatest cause of decline and extinction is habitat loss -Native species live in their historical ranges and exotic species live outside their historical ranges -Species can be overharvested and become endangered -Pollution and climate change can lead to loss of biodiversity -There are two approaches to protecting biodiversity: the single species approach and the ecosystem approach -Some factors that must be taken into account when protecting species are the size and shape of the protected area, the connectedness to other protected areas, and how best to incorporate conservation while recognizing the need for sustainable habitat for humans

What are the factors that determine successful adaptation

-Rate of environmental change: a slowly changing environment gives species more time to adapt to the changes. (negative slope graph) -Genetic variation: Less genetic variation means there is less chance for the species to adapt to changing conditions. (positive slope graph) -Population size: If a beneficial mutation occurs, it can spread more rapidly in a small population than in a large population. (negative slope graph) -Generation time: Shorter generation times increase the chance that beneficial mutations will occur within a given amount of time and allow them to spread throughout a population faster. (positive slope graph)

Key Ideas for Ch 5

-The three levels of biodiversity are ecosystem, species, and genetic diversity -Species richness and species evenness are two different measures of species diversity -When a species is geographically isolated from other populations, two distinct species can form -Natural evolution is an extremely slow process -Artificial evolution can be incredibly fast -Animals have a set of ideal conditions know as their fundamental niche -As environments change, species can adapt, move, or become extinct -Scientist use the fossil record to study species that live millions of years ago -There have been five major times when the Earth has experienced mass extinctions -Scientists believe we are in the sixth mass extinction

Founder Effect

A change in a population descended from a small number of colonizing individuals. If a few individuals from a mainland population colonize an island, the genotypes on the island will represent only a subset of the genotypes present in the mainland population. As with the bottleneck effect, some genotypes will not be present in the new population.

Genetic Drift

A change in the genetic composition of a population over time as a result of random mating. In a large population, the genetic composition tends to remain the same over time. In a small population, however, some genotypes can be lost by chance and the genetic composition can change over time.

Mutation

A mutation can arise in a population and, if it is not lost, may increase in frequency over time and add to the genetic variation. The larger the population, the more opportunities there will be for mutations to occur.

Bottleneck Effect

A reduction in the genetic diversity of a population caused by a reduction in its size. If a population experiences a drastic decrease in size (due to habitat loss, natural disaster, hunting or changes in the environment), some genotypes will be lost, and the genetic composition of the survivors will differ from the composition of the group. The smaller the population size, the smaller the number of unique genotypes that will be present. Often species are less able to adapt to future changes in their environment.

Explain how environmental change affects speciation and extinction

Allopatric and sympatric speciation are two ways in which new species can evolve. Four factors that affect a species' ability to adapt to environmental change are the rate of environmental change, the amount of genetic variation within the species, population size, and generation time.

Summarize the example of allopatric speciation in figure 5.13

Allopatric speciation is the most common way in which evolution generates new species. Geographic barriers can split populations. Natural selection may favor different traits in the environment of each isolated population, resulting in different adaptations. Over time, the two populations may become so genetically distinct that they are no longer capable of interbreeding.

Identify the causes of declining biodiversity

Because each species relies on a particular habitat, a major cause of declining biodiversity is the loss of habitat. Additional causes include overharvesting, legal and illegal trading in plants and animals, introductions of alien species, pollution, and climate change.

What are some of the reasons behind biodiversity decline

Biodiversity decline includes habitat loss, alien (invasive) species, overharvesting, pollution, and climate change.

Native species

species that live in their historical range, typically where they have lived for thousands of millions of years

Explain the concept of biodiversity and how it is measured

Biodiversity exists at three scales: ecosystem diversity, species diversity, and genetic diversity. Environmental scientists measure species diversity both by the number of species in a particular location (species richness) and by how evenly individuals are distributing among those species (species evenness). The greater the number of species, and the more even the distribution, the higher the diversity.

Summarize the idea behind biosphere reserves

Biosphere reserves are protected areas consisting of zones that vary in the amount of permissible human impact. These reserves protect biodiversity without excluding all human activity. Created to address the problem between the balance of human activity and natural protection. The core areas have minimal human impact and outer zones have increasing levels human impacts (core area → buffer zone → transition area)

CITES (1973)

Control the international trade of threatened plants and animals. International agreement among 175 countries of the world. The IUCN maintains a list of endangered species (Red List) and each member country assigns a specific agency to monitor and regulate the import and export of animals on the list.

Explain the concept of an ecological niche

Evolution by natural selection favors combinations of traits that perform well under particular environmental conditions. As a result, each species has a range of preferred abiotic conditions that constitute its fundamental niche. This fundamental niche is further restricted by biotic factors, including competition, predation, and disease, to form the species' realized niche. Changes in environmental conditions therefore have the potential to change species' distributions.

Describe the ways in which evolution can occur

Evolution can occur through artificial selection, natural selection, or random processes. Artificial selection occurs when humans determine which individuals will mate and pass on their genes to the next generation to achieve a predetermined suite of traits. Natural selection does not favor a predetermined suite of traits, but simply favors those individuals that are best able to survive and reproduce. Random processes (mutation, genetic drift, bottleneck effects, and founder effects) do not favor a predetermined suite of traits, nor do they favor individuals with the highest fitness.

Endangered Species Act (1973)

Implements the international CITES agreement. Authorizes the US Fish & Wildlife Service to determine which species can be listed as threatened or endangered and prohibits the harming of such species, including prohibitions on the trade of listed species, their fur, or their body parts. It also authorizes the government to purchase habitat that is critical to the conservation of threatened and endangered species and to develop recovery plans to increase populations.

How do invasive species threaten biodiversity? Give an example of an invasive species

Invasive species are species that live outside their historical range that spread rapidly across large areas. This is possible because invasive species often have no natural enemies/predators in the regions where they are introduced. This allows them to take over beneficial resources in an ecosystem and deplete nutrients for species. An example of an invasive species is the kudzu vine (Japan/SE Asia native that was introduced to the US to help reduce erosion in fields)

Exotic species

species that live outside of their historical range; interchangeable with alien species

Lacey Act (1990)

One of the earliest acts to control the trade of wildlife. Prohibits the transport of illegally harvested game animals, primarily birds and mammals across state lines. Forbids the interstate shipping of all illegally harvested plants and animals. Amendments have been added.

Marine Mammal Protection Act (1972)

Passed in response to declining populations of many marine mammals (polar bears, sea otters, manatees, California sea lions). Prohibits the killing of all marine mammals in the US and prohibits the import or export of any marine mammal body parts (only the US Fish and Wildlife service and the National Marine Fisheries Service are allowed to approve any exceptions to the act).

Explain in your own words the difference between species evenness and species richness

Species evenness and species richness are both measures of species diversity at local or regional scales. The number of species in a given area is species richness. It is used to give an approximate sense of the biodiversity of a particular place. Species evenness tells us whether a particular ecosystem is numerically dominated by one species or whether all of its species have similar abundances. An ecosystem has high species evenness if one species is represented by many individuals while the others are represented by few. This gives scientists a baseline they can use to determine how much an ecosystem has changed.

Alien species

species that live outside their historical range

Explain the ecosystem approach to conserving biodiversity and how size, shape, and connectedness affect the number of species that will be protected.

The ecosystem approach to conserving biodiversity focuses on protecting not just a particular species of interest, but entire communities of organisms that live in an ecosystem. This is the goal of the biosphere reserve program of the United Nations. In protecting areas, we have to consider the theories of island biogeography and metapopulations because we can protect more biodiversity if we save larger areas of habitat that are close enough to each other to allow organisms to disperse.

Understand how genetic diversity, species diversity, and ecosystem function are changing over time

The genetic diversity of both wild and domesticated species is declining, as is the species diversity for all groups of organisms that have been assessed so far. Because species help to determine the function of ecosystems, declines in species diversity have, in turn, caused losses in ecosystem services.

Phylogenies

branching patterns of evolutionary relationships; can be described in a diagram called a phylogenic tree

Describe the sing-species approach to conserving biodiversity including the major laws the protect species

The sing-species approach to conserving biodiversity focuses on saving one species at a time, often by using laws such as Marine Mammal Protection Act and the Endangered Species Act.

How can we reduce species decline

We can reduce species decline through the conservation of biodiversity which includes conservation legislation, biosphere reserves, and the consideration of the size, shape and connectedness of protected areas.

Founder effect

a change in a population descended from a small number of colonizing individuals; bird example- they will give rise to an island population that has a genetic composition very different from that of the original mainland population

Evolution

a change in the genetic composition over time; as an individual you cannot evolve, but you can have a mutation in your genes

Mutation

a random change in the genetic code; a mistake in the copying process can cause this; environmental factors such as ultraviolet radiation from the sun (cancer); occur randomly and can add to the genetic variation of a population

Bottleneck effect

a reduction in the genetic diversity of a population caused by a reduction in its size; an organism's habitat is destroyed, etc. and the population shrinks causing a smaller number of unique genotypes that can be present in the population leading to this effect which has many negative effects such as less adaptability, increased risk of disease, and low fertility

Hotspots

areas especially rich in plant species that are found nowhere else on Earth and are in great danger of extinction (plant diversity used as an indicator of animal diversity)

Endangered

at serious risk of being extinct; ex: of the 200 breeds of domesticated animals that have been evaluated in North America, 80% of those breeds are either declining or already facing extinction

Genetic drift

change in the genetic composition of a population over time as a result of random mating; like mutation it is a non-adaptive random process; common in small populations; ex: black and white haired animals, black fail to find a mate and the black haired phenotype will be lost as the next generation is entirely white haired

CITES

convention on International Trade in Endangered Species of Wild Fauna and Flora; developed in 1973 to control the international trade of threatened plants and animals; today CITES is an international agreement between 175 (178 now) countries of the world

Microevolution

evolution below the species level such as the evolution of different varieties of apples or potatoes; a species changes color, moth example; evolution of a population

Macroevolution

evolution which gives rise to a new species or new genera, family, class, or phyla; basic evolutionary mechanisms- mutation, migration, genetic drift and natural selection

Endangered species act

first passed in 1973, it authorized the US Fish and Wildlife Service to determine which species can be listed as threatened or endangered and prohibits the harming of these species; trading these species is also illegal; the act also authorizes the government to purchase habitat that is critical to the species- often puts jobs and critical habitat in conflict

Fundamental niche

ideal conditions for a species, everywhere it "could" live; although the fundamental niche establishes the abiotic limits on a species persistence there are often biotic factors that further limit the physical locations where it can live (predators, competitors and diseases)

Convention on biological diversity

in 1992, nations came together and made a treaty to protect biological diversity; the treaty had three objective: conserve biodiversity, sustainably use biodiversity, and equitably share the benefits that emerge from the commercial use of genetic resources such as pharmaceutical drugs

List the four random processes the can cause evolution

mutation, genetic drift, bottleneck effect, founder effect.

Recombination

occurs as chromosomes are duplicated during reproductive cell division (meiosis) and a piece of one chromosome breaks off and attaches to another chromosome; does not create new genes but does bring together new combinations of genes on a chromosome and can therefore produce novel traits; ex: when fighting off viruses and bacteria, recombination allows new combinations to come together, providing new immune defenses that may prove effective against invading organisms

Inbreeding depression

occurs when individuals with similar genotypes, generally relatives, breed with each other

Lacey Act

one of the earliest laws in the U.S. to control the trade of wildlife; first passed in 1900, the act prohibited the transport of illegally harvested game animals, primarily birds and mammals, across state lines; over the years, a number of amendments have been added so that the Lacey Act today forbids the interstate shipping of illegally harvested plants and animals

Fitness

organism's ability to survive and reproduce

Genes

physical locations on chromosomes within each cell of an organism

Geographic isolation

physical separation of a group of individuals from others of the same species

Marine mammal protection act

prohibits the killing of all marine mammals in the US and prohibits the import or export of any marine mammal body parts; was passed in response to declining populations of many marine mammals, including polar bears, sea otters, manatees, and California sea lions; only the US Fish and Wildlife Service and the National Marine Fisheries Service are allowed to approve any exceptions to the act

Biosphere reserves

protected areas consisting of zones that vary in the amount of permissible human impact; these reserves protect biodiversity without excluding all human activity

Fossils

remains of organisms have been preserved in rock; much of what we know about evolution comes from the fossil record; can be used to determine when different species existed on earth

Genetically modified organisms

result of gene splicing; takes much less time than traditional crossbreeding (average rate is 1%) - genes from species that would never interbreed in nature are being transferred to each other; cloning can produce genetically identical versions (good and bad) -> banana story; people point out that most new technologies have had unintended and harmful consequences so caution is advised Scientists copy genes from a species with some desirable traits and then insert these genes into other species of plants, animals, or microbes to produce GMOs and when they reproduce they pass on inserted genes to their offspring

Red list

the IUCN list of threatened species; each member country assigns a specific agency to monitor and regulate the import and export of animals on the list; for example, in the US, oversight is conducted by the US Fish and Wildlife Service

Phenotype

the actual set of traits expresses in an individual; ex: anatomy, physiology, behavior; the color of eyes is phenotype, where the genetic code for that color is genotype

Edge habitat

the area where two different communities come together, typically forming an abrupt transition; ex: a grassy field meeting a forest

Distribution

the areas of the world where the species actually lives

Genotype

the complete set of genes in an individual

Evolution by natural selection

the environment determines which individuals are most likely to survive and reproduce

Sympatric speciation

the evolution of one species into two species in the absence of geographic isolation, usually through the process of polyploidy, an increase in the number of sets of chromosomes - normally have two sets (diploid) but this increases it to three, four, or even six sets; occurs almost exclusively in plants

Range of tolerance

the limit to the abiotic conditions they can tolerate; bell curve where they can survive, survive and grow, survive grow and reproduce

Species richness

the number of species in a given area, such as a pond, the canopy of a tree, or a plot of grassland; used to give an approximate sense of the biodiversity of a place

Realized niche

the range of abiotic and biotic conditions under which a species actually lives

Reproductive isolation

the result of two populations within a species evolving separately so they can no longer interbreed and produce viable offspring

Ecosystem diversity

the variety of ecosystems within a given region

Genetic diversity

the variety of genes within a given species

Species diversity

the variety of species within a given ecosystem

Adaptations

traits that improve an individual's fitness

Invasive species

when alien species spread rapidly across large areas -Lack natural predators -Act as predators, pathogens, or superior competitors -Often pre-adapted to environmental conditions -Ex: Kudzu Vine, Zebra Mussel, Silver (Asian) carp

Evolution by artificial selection

when humans determine which individuals to breed; good and bad- we can accidentally select a herbicide resistant weed or antibiotic resistant bacteria

Mass extinctions

when large numbers of species went extinct over a relatively short period of time

Allopatric speciation

when new species are created by geographic or reproductive isolation; occurs when a population is geographically isolated for a long time and the gene pools are so changed that members become so different in genetic makeup that they cannot produce fertile offspring and are thus reproductively isolated; mouse example

Extinction

when there are no longer any of the species in the world