BLG567: parasitism and biodiversity

What is a parasite?

an organism that lives in or on another organism (its host) and benefits by deriving nutrients at the host's expense. (+, -)

What is an Ectoparasite?

a parasite that lives on the outside of the body, such as a tick, mites, lice, fleas

What is endoparasite?

A parasite that lives within a host, such as viruses, bacteria, protists, and fungi

What is host-parasite coevolution?

Occurs when a host and parasite adapt to live with each other and eventually create a coevolutionary arms race.

What is an example of host-parasite coevolution?

Invasive rabbits in Australia. Purposefully released myxoma virus, a biocontrol. Upon initial release: very effective and killed 99.8% of rabbits, however those 2% that survived had become resistant to the virus. Overtime the biological control is not as effective as it once was.

What is the difference between infection tolerant and infection resistance?

Infection tolerant is the impact that the parasite has on an organisms fitness, and infection resistant is the ability for the host to prevent infection from occurring

What is habitat heterogeneity?

diversity or variety in habitat types

How are parasites transmitted?

Vertical: Parent to offspring, transmitted to generation to generation

Horizontal: individual to individual, jump from species to species

What is a zombie parasite example?

a Parasite that affects certain insects, such as snails. Snails eat bird poop and bird poop usually contains flatworms. By eating it, the snails will become affected by the parasite. The parasite makes the snails look like caterpillars because birds like to eat caterpillars. When birds eat the snail infected with the parasite, the bird ingests the parasite. When birds poop, it will contain the flatworm parasite, which is beneficial for the parasite as it will continue to spread. The parasite will make the snail come out during the day to attract more predators, as they usually avoid the daytime.

What is hemiparasite and one example of it?

A hemiparasite is a plant that may obtain part of its food by parasitism, an example would be mistletoe. Mistletoe does photosynthesize, however it does obtain it food through predation

How can parasites impact population size?

population cycling, through delayed density dependence, energy stores, predator/ prey interactions

What are the two hypothesis that explain diversity and latitude in populations?

Hypothesis 1: lack of glaciation in tropics

Hypothesis 2: habitat heterogeneity and resource availability =greater speciation and lower extinction

What is host-parasite coevolution in humans?

Parasites that can switch from animals to humans, e.x. pubic lice

What are legacy effects?

Marks on landscapes that create a different environment, different elevation, soil texture, more soil, they tend to support unique communities

What determines diversity levels?

Scales. The small scale consists of capturing fewer species. The large scale supports more viable diversity

Other effects include global examples, such as tropical temperature regions. effects of continental drift, time since glaciation, habitat heterogeneity

How do natural disasters effect habitats?

After wildfires, soil richness increases. Removes older trees susceptible to insects and disease. Removes litter, increases soil nutrients, promotes seedling growth

What occurs in fire dependent species, for example, Jack pines?

Jack pines are pine cones with a waxy coating, protecting the seeds from dispersing. However, the only thing that can break open these pine cones is fire. After a fire has occurred, the pine cones burst open and release the seeds inside, dispersing them and allowing them to grow in the now nutrient-rich soil provided by the fire.

True or False:

Natural disasters allow variety within populations

True

What are some threats to biodiversity?

Occurs when a new competitor comes in as a threat and cause disruptions that limit the resources needed by an organism, alter how an organisms interacts with other organisms (competition and predation), habitat loss and fragmentation is the biggest and most urgent threat, cannot exchange genetic information, isolated habitats, smaller habitats, etc.

What are the three way of quantifying biodiversity?

Alpha, gamma, beta

What is alpha diversity?

Small scale, one sight, local diversity, single localized habitat, quantifying diversity in one area, calculated by determining how many different species there are in one area.

Determine the alpha diversity of habitat 1

Habitat 1: pine, oak, sugar maple, robin, dandelion

Habitat 2: super maple, pine, oak, blue jay, may apple

5

What is Gamma diversity?

Bigger scale, multiple locations, regional area of diversity, landscape level. The diversity of the entire region. calculated by counting species in both habitats but do not count them twice.

Determine the gamma diversity

Habitat 1: pine, oak, sugar maple, robin, dandelion

Habitat 2: super maple, pine, oak, blue jay, may apple

7

What is beta diversity?

used to compare two sights, similarities between two habitats/locations, several indicies exist. calculated by determining the number of species

Determine the beta diversity.

Habitat 1: pine, oak, sugar maple, robin, dandelion

Habitat 2: super maple, pine, oak, blue jay, may apple

4

What is an ecosystem engineer?

any organism that creates, significantly modifies, maintains or destroys a habitat, such as a woodpecker, modify habitat to create suitable conditions for other bird species or a beaver, which turns fields into wetlands

What is habitat fragmentation?

The breakup of habitat into smaller pieces, usually as a result of human activities. Tends to increase isolation, reduce population sizes and may reduce genetic exchange among populations

What is the theory of island biography?

When islands are larger in size, they are able to support much more species and larger populations.

What are the two postulates that contribute to the island biogeography?

Postulate #1: island size is positively correlated with species richness, the larger the habitat patch, more species you will find

Postulate #2: distance from the source, colonizing, population is negatively correlated with species richness

What is a species-area relationship?

A phenomenon not isolated to islands, such as a wetland. Tends to support more mammals, greater diversity of a species, variation in data

What is the equilibrium theory of biogeography?

number of species reflects balance between colonization of new species and extinction of existing species

True or False:

Species may go extinct on islands, yet small islands support smaller populations

True

True or False:

isolation and colonization rate directly impact each other

True