Module 3: Ecology and Evolution

What is ecology?

Interactions that living things have with each other and the environment; includes both biological and non-biological interaction

Does ecology consist of non-biological interaction?

Yes

Individual organism is an example of

the first level of ecology

Population is an example of

the second level of ecology

Community is an example of

the third level of ecology

Ecosystem is an example of

the fourth level of ecology

Biosphere is an example of

the fifth level of ecology

The study of individual organisms

allows us to understand the role any given species has in its environment

What is an ecological niche?

The role and position a species has in its environment

The study of population

allows us to understand if the environment is healthy and sustainable; individuals of 1 species that shares a defined space/environment

The study of communities

allows us to understand the relationships between predators and consumers/impact of new or invasive species; all the populations that live in a defined area and interact with each other (plants+animals)

The study of ecosystems

allows us to understand how changes to the environment impact the health of the living organisms that share it; includes living and non-living factors

What are examples of non-living factors that could be affected within a ecosystem?

seasons, weather, water, rocks, soil, tides…

The study of biosphere

allows us to understand how life survives and changes on Earth; includes most of the entire planet that have living organisms

Which of the three levels of ecology are usually interconnected?

Organisms, populations, and communities

What is population dynamics?

The study of how population changes over time

What are considered ideal conditions?

Organisms are placed in an environment with unlimited resources and temperatures that allows them to thrive

What are the ideal conditions of bacteria?

moist, warm, nutrient-rich environment

What affects the squirrel population on the CSUS campus?

birth rate, carrying capacity, death rate, migration

Within ideal (unrealistic) conditions, nearly all populations will grow at

an exponential rate (keep going up)

What could cause a population to not grow exponentially?

Limited amount of resources

What is logistic growth?

Over time, a population’s size gets larger but growth is limited due to limited resources; population size stabilizes

What is carrying capacity?

the maximum number of individuals that a defined area or environment can sustain with its available resources

What is community ecology?

How species interact with one another

In symbiosis, at least one party always

benefits from it

What is Predation and Herbivory?

When an organism feeds on another…predator(typically animal)-prey(animal or plant); one benefits while the other is harmed

What are some examples of defense mechanisms used against predation and herbivory?

Physical defense, chemical defense, mimicry, and camouflage

What is an example of chemical defense?

plant nectar produces toxins that once eaten will cause indigestion

What is an example of physical defense?

thorns on a bush to prevent animals from eating its leaves

What is an example of mimicry?

Bees evolving to look similar to that of wasps to deter predators

What is an example of camouflage using one’s color and body?

Insects use its stick-like body and green colors to blend into the foliage, chameleon using its green colors to blend into foliage

What is commensalism?

interaction in which one species benefits while the others is neither harmed nor helped

A bird building a nest in the trees is an example of

commensalism

What is mutualism?

Interactions in which both species benefits

The relationship between termites and protozoa (insect eats wood and bacteria breaks down cellulose); bacteria lives in gut of termites is an example of

mutualism

Lichen; algae(produce glucose) & fungi(protects algae) is an example of

mutualism

What is parasitism?

predator feeds slowly and doesn’t kill the prey immediately

Mistletoe sucking nutrients from a tree is an example of

parasitism

What is coevolution?

When two species each evolve adaptations because of their interaction with another species

The relationship in which flowers have evolved brighter colors to attract insects to spread their pollen is an example of

coevolution

Nearly all populations will grow at an exponential rate under

ideal conditions

What are the three types of symbiosis?

commensalism, mutualism, and parasitism

If a resource is vital to two species, the competition for it will usually drive one species to

local extinction

What is the Competitive Exclusion Principle?

If a resource is vital to two species, the competition for it will usually drive one species to local extinction

The relationship between termites and protozoa are an example of

mutualism

Why is the relationship between termites and protozoa considered beneficial to both?

Protozoa feed and are protected from predators while living inside the guts of termites; termites eat wood and need their help to digest the cellulose in order to use it for energy

Lichen is an example of

mutualism

Why is lichen an example of mutualism?

Lichen is found on trees and consists of algae and fungi. The algae produces glucose via photosynthesis and the fungi protects the algae while also benefiting from the glucose production.

According to Darwin’s theory of evolution

all life forms on earth have descended over time from common ancestors

Darwin presented his theory of evolution and natural selection by observing

beaks of finch birds in the Galapagos

What did Darwin’s observation of finch birds allude?

After the drought of 1977, the amount of small-soft seeds became limited and birds with beaks that relied on this food source decreased, while birds with beaks that can open the large-hard seeds thrived

In order for evolution to take place, you need

variation

Variation can occur due to

random mutation (random change in genes) or sexual reproduction (combination of genes that thrive in a certain environment)

What is adaptation?

A trait passed down to the next generation that is beneficial to it, helps it thrive

Depending on the environment, natural selection can provide an advantage if it

is passed down to the offspring and they benefit from it

Depending on the environment, natural selection can provide a disadvantage if it

is passed down to the offspring and they don’t benefit from it, trait won’t be passed down far down the line

Mutations are _____ present in populations

always

Mutations can be beneficial

leading to better survival and ability to reach sexual maturity

Mutations can be harmful

the individual likely won’t make it to sexual maturity or won’t have offspring

Mutations can be neutral

the gene will not have a significant impact on the individual, nothing will happen and it may or may not be passed down

What is another term for genetic drift?

bottleneck effect

How does the genetic drift/bottleneck effect contribute towards variety within evolution and natural selection?

a chance event (disaster) happens that causes a subset (random/specific) of the population to live and therefore they are they ones that pass their genes down to the next generation

What is gene flow?

Flow/mixture of genes from different regions and populations due to migration; transfer of genetic material from one population to another and increasing variety

What are fossils?

preserved remains of organisms

What are fossil records?

timeline that gives order to when organisms existed

Fossils serve as evidence for

when certain species came into existence and went extinct

About __ of all species that have ever existed have gone extinct

99%

What are our evidences for evolution?

fossil records, anatomy, molecular biology

What are analogous structures?

Structures of organisms that have different internal structures but appear similar externally and have similar functions due to environmental adaptation

What do analogous structures show in evolution?

organisms do not have a common ancestor; they evolved independently in two lineages; developed similar features to one another due to environmental adaptation

What are homologous structures?

Structures of organisms that have different functions and outward appearance but similar internal designs

What do homologous structures show in evolution?

Similar internal bone structures show that organisms share a common ancestor

Molecular biology is the study of

DNA (genetic material) and relatedness between species

What is the importance of the stickleback fish example in evolution?

In sea water, their spines protected them from predators so they thrived; in fresh water—> more spines, their spines made them an easier target for predators to grab them so they diminished —> lost their spines as those mutated without spines had a higher chance to survive to sexual maturity and reporduce

What are the six misconceptions of evolution?

evolution is just a theory, Individuals evolve, evolution explains the origin of life, organisms evolve on purpose, evolution is controversial, other theories should be taught

Why is “Evolution is just a theory“ a misconception?

A theory ties extensive evidence together to explain something, but evolution is in fact regarded more as a law, in which it is a descriptive principle of nature

What is a hypothesis?

an educated guess as to what might happen

What is a theory?

an explanation that ties together facts, explanatory principles after finding extensive evidence

What is a law?

a descriptive principle, similar to that of a mathematical equation

Why is “Individuals evolve“ a misconception?

individuals can not simply change and evolve over their lifespan; evolution happens due to mutations from birth or a mixture sexual reproduction genes, therefore could only be changed within populations over time

Why is “Evolution explains the origins of life“ a misconception?

Only focuses on what happens after life has started (observing dead remains), not trying to identify how life started

Why is “Organisms evolve on purpose“ a misconception?

Organisms can not choose to evolve on their own accord, evolution happens due to variation and environmental factors that decide which genes are best suited for a particular area, thus, they evolve to adapt to that area

Why is “Evolution is Controversial Among Scientists” a misconception?

97% of scientists accept evolution; adopted within scientific community within 20 years

Why is “Other theories should be taught“ a misconception?

There are no other theories that have enough substantial concrete evidence that can explain these changes like this evolution theory can

What is special creation?

beliefs that relies on untestable explanations

What is intelligent design?

beliefs that relies on unknown or supernatural factors that can not be tested

What is biodiversity?

a broad term for biological variety

How is biodiversity measured?

the number of different species and number of individuals of one species

Biodiversity is important for humans and

the maintenance of every species

What are the three types of biodiversity?

genetic and chemical diversity, ecosystem diversity, and current species diversity

Genetic and chemical diversity refers to

variety of genes and alleles in a species, genomes (DNA) of a species, and metabolic compounds

What does metabolic mean?

made from the metabolism of a living organisms

The different combinations of genomes in the environment result in

different chemical combinations being made

Ecosystem diversity refers to

variety of ecosystems on Earth

Loss of an ecosystem results in

the loss of species in that area

Rich prairie lands being depleted of its natural nutrients and minerals by being used as farmlands is an example of

loss of ecosystem diversity

According to the table provided in the PowerPoint slides, current species diversity is

us having very little knowledge of what’s out there, we can only count/record so much info, but there are more predicted species out there

What are the six human impacts on biodiversity

overpopulation, urban sprawl, natural resource depletion, deforestation, pollution, invasive species

How does the overpopulation of humans impact biodiversity?

Ever since the industrial revolution, humans have had access to an excess of resources therefore undergoing exponential growth

How does the urban sprawl of humans impact biodiversity?

increased population and unrestricted growth lead to the need to expand housing, building more houses takes up space from the natural biodiversity of the environment