Bio Invaders Midterm

PCB2441 - UF Fall 2023 [scored 89.25% on exam]

What are invasive species?

non-native to the ecosystem and whose introduction (likely spreads rapidly) causes/is likely to cause economic, environmental, or human health harm

Where did the term “invasive species” come from?

Ecology of Invasion by Animals and Plants

Who coined the term “invasive species”

Charles Elton

When did the term “invasive species” start?

1958

How old is the study of invasive species?

relatively young

Are all non-native species invasive?

no

What is water hyacinth classified as?

non-native and invasive

What is striped bass classified as?

native to NE America but non-native to SE America

What is maize/corn classified as?

non-native but non-invasive

What are Carolina, Cattail, Eastern Red Cedar classified as?

native and invasive

How many species are invasive globally?

4-44%

Why is there a large discrepancy in invasive ecology knowledge?

Most studies are done in first-world countries

How many non-native species are in the US?

50,000

Are all non-native species accidental?

NO - some species are cultivated and domesticated

What are some other terms for invasive species?

alien species, noxious weed, exotic, non-native, non-indigenous, introduced species, naturalized

Are other terms for invasive species synonyms?

NO - they are related terms

What does the Blackburn Model present?

the barriers and stages needed to overcome for successful invasions AND the types of management needed for each stage

What is the first stage of the Blackburn Model?

transport and introduction

How are invasive species introduced and transported?

1) usually by humans

2) can be intentional or unintentional

3) species escapes captivation

What is the second stage of the Blackburn Model?

establishment

Why do some species fail to establish?

factors associated with the species (biotic factors) or location (abiotic factors)

What are some biotic factors that affect the establishment of a species?

species reproduction, predators, competition, disesases

What are some abiotic factors that affect the establishment of a species?

location, climate

What is the third stage in the Blackburn Model?

spread

What are some factors that affect the spread of a species?

limiting abiotic factors OR adaptation to spread farther

What is the fourth stage of the Blackburn Model?

impact

What is considered a successful impact for invasive species?

species population dominates

What is impacted by invasive speces?

community and ecosystem

What are the 4 types of management?

1) prevention

2) eradication

3) containment

4) control/management

When is prevention most impactful?

prior to invasion

What is ecological biodiversity?

variation in ecosystems in a region or globally

What is species biodiversity?

variation in species in an area or region

What is genetic biodiversity?

variation in genetics within a species

What is perpetual change?

all species and continuously changing

What are the rules of nature?

combined influences of physical and biological limiting factors action upon organisms

What controls evolution/natural selection?

nature, its NOT goal-oriented or anticipatory

What are limiting factors?

any biological or physical factors which regulate the welfare of an organism

What are some types of limiting factors?

disease, competition, predation, environmental change

What is evolution?

gene pool of the population changes over time

How long does evolution take?

usually over a long period of time

What is the first step of evolution?

mutation

What does mutation do to a species?

leads to changes in the phenotype

What is the second step of evolution?

genetic variation through mutation

What does genetic variation do to a species?

changes the genotype

What is the third step of evolution?

natural selection acts upon the phenotype

What is the fourth step evolution?

individuals more suited to the environment produce more offspring

When does speciation occur?

if geographic and reproductive isolation mechanisms exist

Who is affected by evolution?

populations NOT individuals

What are the 3 types of natural selection?

1) directional

2) stabilizing

3) disrupting/diversifying

What is directional natural selection?

when allele frequencies shirt to favor individuals at one extreme of the normal range

What happens during directional natural selection?

one side of the distribution reproduces more than the other

What is the result of directional natural selection?

population looks different ( → → | )

What is stabilizing natural selection?

when a population favors individuals with an average genetic makeup

What happens during stabilizing natural selection?

only the middle of the distribution reproduces

What is the result of stabilizing natural selection?

the population looks more similar ( → | ← )

What is disrupting/diversifying natural selection?

when environmental conditions favor two groups at the same time

What is the result of disruption/diversifying natural selection?

population splits into two groups ( | ← → | )

What is speciation?

two species arise from one

Why does speciation occur?

there is reproductive isolation

What the 4 types of reproductive isolation?

1) geographic

2) temporal

3) behavioral

4) anatomical

What are the 2 types of speciation?

1) allopatric

2) sympatric

What is allopatric speciation?

members become so different that they can no longer interbreed

When does allopatric speciation occur?

when two groups of the same species are geographically isolated

Why does allopatric speciation occur?

allele frequencies change over time

Why does sympatric speciation occur?

behavioral barrier, hybridization, or polyploidy

When does sympatric species occur?

population evolves with overlapping ranges

Why should we preserve biodiversity?

genetics, bio-control agents, food sources, natural products, environmental services, enjoyment, scientific interest, self-perpetuation, future/potential uses

What is an endemic species?

those that occur in a particular area or region but nowhere else?

What are the 4 scales of isolation?

1) macroscale

2) mesoscale

3) microscale

4) bio-scale

What is macroscale isolation?

isolation from different continents

What is the result of macroscale isolation?

mammals can not move freely and compete with similar species, preventing major extinction

What is mesoscale isolation?

islands or habitats that function as islands

What is microscale isolation?

semi-isolation habitats within an area

What is bio-scale isolatino?

isolated areas of the same organism

Why are islands more vulnerable to invasions?

1) Evolved in isolation from competitors, predators, and pathogens

2) Highly disturbed by human use

3) Humans discount the value of native species and introduce species from other areas

4) Initial invasion can enable or facilitate additional invasions (invasion meltdown)

Why are continents less vulnerable to invasions?

1) Species on continents are more resilient to disease and predation

2) If an invasion causes a species extinction in one area, it is likely that the species has persisted elsewhere on the continent

What are some factors to the distribution of biodiversity?

1) old habitats = rich habitats

2) diversity is self-reinforcing

3) isolated places are more likely to have unique species

4) divided landscapes create more species

What is convergent evolution?

when a population/species is in isolation and can independently evolve similar traits

What is happening to the species introduction rateto Hawaii?

increasing quickly (1 species every few months v. 1 species every 5-7k years)

What has had the greatest impact on native species?

global invasion of humans

What did the global invasion of humans cause?

megafauna extinctions

Why was Africa not affected by megafauna extinctions?

the coevolution of humans and African species prepared them for threats

What are the 3 types of transport technology?

1) speed of travel

2) cargo capacity

3) conditions during transport

What did multiple-sail ships change about transport?

caused regular trips across the Atlantic

What 3 types of introductions did Atlantic trips cause?

1) intentional agricultural/livestock species

2) unintentional hitchhikers (insects, pathogens, rats)

3) unintentional ballast (sources of weeds, insects)

What was the net flow of species introduction from Atlantic trips?

Europe → Americas

What are 5 examples of mechanization that altered transport?

1) large boats

2) railroads

3) containerization

4) air travel

5) Panama Canal

How did large boats affect transport?

haul more, haul faster, travel upstream, affordable transport, haul raw goods → survival for sensitive species

What risk does containerization pose for introductions?

lack of inspection

What does air travel change for introductions?

increased speed of travel

Why is invasion happening more than its prevention?

1) technology/globalization increased rapidly

2) policies/funding has not kept up

What are the 7 traits of invasive animals?

1) fast growth rate

2) high fecundity (offspring)

3) reproductively mature quickly

4) few predators or diseases

5) tolerate a wide range of conditions

6) broad diet

7) high competitive

What are the 8 traits of invasive plants?

1) fast growth rate

2) high fecundity (seeds)

3) few predators/diseases

4) thrive under disturbed conditions

5) habitat generalists

6) extended phenology (photosynthetic period)

7) some exhibit allelopathy

8) alter soil conditions

What are the 5 mechanisms of invasions?

1) propagule pressure

2) abiotic factors

3) biotic factors

4) human modification

5) interactions between P, A, and B

How is propagule pressure measured?

size x frequency

What is propagule size?

number of individuals released at any one time

What is the frequency of propagule introductions?

how many introductions

What is important for invasion success?

high quality and propagule pressure

What are 3 reasons why high propagule pressure positively affects invasion success?

1) increases genetic diversity

2) increases the probability that propagules will encounter favorable environmental

3) results in seeds swamping

What are 2 hypothesizes for propagule pressure?

1) null hypothesis - simplest explanation

2) acts as a prerequisite for invasions