Biological diversity chapter 16

Did Darwin come up with evolution?

no he came up with the mechanism to explain evolution

evolution acts on ________ but we measure based on ______

individuals (phenotypes), population (looking at alleles)

true or false all animals produce more offspring than can survive? if true what does this lead to?

true, this leads to lots of competition for resources.

true or false all traits are based on environment

false some traits are based on genetics, some are based on environment

does evolution have an end goal?

evolution does not have an end goal.

what is inference?

differential reproductive success

what is differential reproductive success?

a composite measure of how well you survive and reproduce (in terms of the local environment)

what are some examples of why we learn evolutionary biology?

antibiotics causing super bugs and HIV needing a cocktail of drugs to be effective against it

What is natural selection?

when an animal selects a mate based on inheritable things that will lead to being more likely to survive

what is artificial selection

when humans force animals with certain phenotypes to reproduce (ex. dogs)

What is your fitness level if you dont reproduce?

zero or near zero

true or false evolution is slow

false evolution can occur quickly (for some flies it can evolve over hours, days, weeks.

if evolution is slow what occurs over a long time?

speciation

what is a hypothesis?

a conjecture which may or may not be true

what is a theory?

an idea which is tested over and over which has not been refuted just refined

true or false evolution is a theory about the origin of life?

false, evolution by natural selection is focused on how life ad survival changed after origin

is evolution linear?

no

is fitness different based on who you mate with?

yes

Is evolution the same as natural selection?

no

true or false evolution is random

false it is not random. only some variants survive

does natural selection try to adapt?

no natural selection does not give what they need it just acts on the phenotype/genotype most likely to survive

does natural selection give organisms what they need?

no natural selection is constantly changing and if there is no phenotype that fits the environment that organism will go extinct

what is kin selection?

where you would do anything to let your kind survive

what is direct fitness?

when you have your own kids

what is indirect fitness?

when you help your family have kids

What is altruism?

behavior of an animal that benefits another at its own expense (ex. prairie dog)

is evolution a theory?

yes

How do evolutionary biologists study evolution?

by studying species with a quick turn around time

true or false evolutionary biology is unifying across all life sciences?

true

true or false evolutionary biology cannot be integrated into psychology?

false evolutionary biology can be used to explain alot of different topics

what explains diversity/ is an important driver of evolution?

natural selection

what can evolution help explain?

diversity of life and how populations evolve over generations in response to environmental pressures

What is considered human mediated evolution?

artificial selection

true or false humans don’t have the same selection pressure as other animals

true

Can humans adapt and evolve during their lifetime?

no that is why you look cross generation

is fitness a set measure?

no fitness is a relative (dynamic process) that changes based on phenotypes and the surrounding environment

endomentional space measures _____

fitness

What is a population?

a group of interbreeding individuals of a species that live together in a specific place

true or false heritability is not a continuum

false heritability is a continuum

is it considered selection if there is no genetic component?

no

what does evolution come from?

variability and the heritability of that variation

did darwin study darwin finches or mocking birds first?

mocking birds

What is adaption?

an inherited characteristic making it better for survival and reproduction.

does adaption continue if the environment stays the same?

yes if the environment is stable the adaption will make it even more suited or that field

What is fitness?

a composite measure of survival and reproductive success (a relative measure for that specific generation)

does fitness require variable components?

yes

Mutation

random heritable changes in the DNA sequences.

what can cause mutations

• errors in DNA replication

• physical agents

• chemical agents

• biological agents

do prey adapt to the environment?

yes

can there be more than one peak (optimum) fitness?

yes you can have two peak (optimum) fitness

What is the rate of change in a population determined by?

generation times, shorter generations change quicker

What are the two ways you can study natural selection and fitness?

passive and active study

What are some examples of model studies for evolution?

• darwin finches

• flies

• yeast

• stickelback

• guppies

• mice

• zebrafish

• bowerbirds

What is natural theology?

aristotle’s classification system mixed with biblical creation

What were the three main points stated by natural theology?

• organisms had been specially created by god

• species could never change or become extinct

• new species could never arrise

Who developed the branch of biology that classifies organisms (taxonomy)

Carolus Linnaeus

how did Carolus Linnaeus develop taxonomy?

started naming things based on phenotypes, used common phenotypes as genus and determined common ancestry

are aquired characteristics inherited?

no they are not inherited

what is epigenetics?

the study of noninherited factors that affect genes

Why is darwin’s voyage important?

because he observed biodiverse animals with different phenotypes surviving in different areas

what three major areas of studies provided insight for darwin?

Geology and fossil records

• studying geology (new at darwins time)

• earth was older than originally thought

• looks at fossils

geographic and distribution of species

• travel was rare so they usually only saw one phenotype for an animal

comparitive morphology of species

• people paid to shoot animals for museums for people to see different animals

What information did earths geology and the fossil records give?

• change in the earths lay out (marine fossils found on mountain)

• species CAN go extinct

• and fossils showed things could evolve

what is biogeography ?

studies of the world distribution of plants and animals

What are vestigial structures?

useless parts observed today- must have functioned in ancestral organisms

What is homology

the study of likeness (inherited by a common ancestor)

what is homoplasy?

similarities but not inherited by a common ancestor just due to similar environment (ex. sharks and orcas)

What is coevolution

where organisms evolve with the environment

What was darwins conclusion?

all organisms are related by a common ancestor but have changed or evolved over time

How many years did darwin wait to publish his findings and why?

12-14 years and he waited because he was worried about backlash

Who had an idea similar to darwins?

Wallace

Why did darwin finally publish his findings?

because Wallace sent him a letter with the same idea so darwin rushed to publish it

What was Malthus influence on Darwin and Wallace?

stated that gains in agricultural technology cant keep up to allow proper food supply if populations grow exponentially, this influenced Darwin and Wallace idea of competition

What is carrying capacity?

the number of resources able to support a specific number of individuals

true or false humans can artificially increase the carrying capacity until a certain threshold

true

What is evolution?

the change in allele frequency over time

How many factors affect evolution and what are they?

4:

1. natural selection

2. drift

3. migration

4. mutation

What is the primary mechanism of evolution

natural selection

true or false mutations play a bigger role in evolution than was once believed

False, mutations play a smaller part in evolution than was one believed

What were darwin’s original 4 postules

1. individuals within populations are variable

2. the variables among individuals are at least in part passed from parents to offspring

3. in every generation, some individuals are more successful at surviving and reproducing than others

4. survival and reproduction of individuals is not random

What are the semantics of natural selection?

darwinian fitness and adaption

What is darwinian fitness?

the ability of an individual to survive and reproduce in its environment

is darwinian fitness a relative measure?

yes

What is adaption?

trait or characteristic of an organism that increases its fitness relative to individuals without the trait

Did darwin study darwin finches?

no, they were just named after darwin

How long have they been studying the fitness of darwin finches on the island?

since 1973

What is sexual dimorphism?

a size difference due to sex

What is sexual chromatism

a different colour due to sex

What would be the trendline of a variable trait if it was not due to inheritance? why?

flat because there would be no relationship between the parents and the kids

what is the gene responsible for coding for beak size?

BMP4

is the survival and reproduction random for darwin finches?

no it is nonrandom

Is natural selection forward looking?

no it is not looking forward, natural selection is adapted to previous environments and may or may not help depending on if that environment has changed

is natural selection nonrandom

yes it is not a random process despite mutation being the source of variation

what is an example of evolution due to mutation?

bullet in the car analogy

is fitness circular?

no its not, the fitness is reliant on variations that survive and reproduce, the theory defines favorable as the ability to survive and reproduce. only requirement is the variant needs to be heritable and not random

does natural selection act on populations?

no, natural selection acts on individuals and is not for the good of a species just for the ability to survive and repopulate

does natural selection need to perfection?

no it does not.

What were the original roadblocks for evolution

1. how was variability generated in populations

2. how were “variations” passed onto the offspring

3. age of the earth (Lord Kelvin’s calculations)

what two propositions does modern synthesis rely on

• gradual evolution results from small genetic changes that are acted upon by natural selection

• the origin of a species and higher taxa (macroevolution) can be explained in terms of natural selection acting on individuals (microevolution)

how is darwins first postule (individuals within populations are variable) now read?

(now that genetics are understood) it is read as a result of mutation creating new alleles and segregation and independent assortment shuffling alleles into new combinations, individuals within populations are variable for traits

How is darwins second postule (the variations among individuals are atleast in part passed from parents to offspring) now read

individuals pass their alleles onto their offspring intact (discrete units; one from mom one from dad)