Bio 11 H -Evolution test

what do all living things contain

DNA

Linnaeus contribution to evolutionary theory

system for classifying specias, naming species (taxonomy)

Who is Cuvier, what is catastrophism

studied fossils of extinct plants/animals

evidence that extinction occurs and species disappear overtime

catastrophism: differences in fossils found in rock layers were caused from catastrophic events such as floods /droughts not because of evolution

what did Hutton propose

Gradualism

whats Gradualism

earth changes slowly and gradually overtime

it takes millions of years to create major changes ex lakes,mountains

what did Lyell propose

Uniformitarism

whats Uniformitariarism

rates and effects of geological processes remain uniform and balance out overtime

ex erosion wears away rock, geological processes will create new landforms overtime

what hutton and lyells ideas, darwin concluded that…

the earth must be very old and slow processes can produce substantial change

whos is Malthus

economist → looked at how human populations changed due to famine, war, diseases lead to scarce and limited resources

darwins view: saw that humans changed over generations through selective breeding → species could be the same

What do we use in farming

artifical selection → choose to breed certain plants or animals with specific traits

ex corn →breed the biggest seed→big corn

Gradualism

changes is slowly and gradually overtime

Punctuated Equilibrium

long periods of stability followed by periods of rapid change

What did Lamark do? What does “use and disuse” mean

use and disuse→ use it or lose it

use the trait or lose it

→adaptations a parent developed in their life could be passed down to offspring

ex. giraffe long necks to reach tall trees→ passing down trait to offspring

his explanation was INCORRECT

darwin suggested: natural selection leads to evolution overtime

why was lamarks theory wrong -giraffe example

he thought that since giraffes necks get longer through its lifetime, that that trait would be passed down to offspring.

however, traits(giraffes long neck) an organism develops during its lifetime usually aren't passed down to its offspring through its gene

Giraffes naturally had different neck lengths because of inherited genetic variation.

whats natural selection

natural process where fitter organisms survive to reproduce, passing those traits to their offspring

ex.peppered moths

fitness meaning

physical traits or behaviours allowing organisms to survive and reporduce

adaptation meaning

an inherited trait that helps organisms to be better suited to its environment to survive and reproduce

evolution definition

gradual change in inherited traits of a population over generations

leads to new and different forms of organisms better adapted to their environment

darwins view: descent with modification summarizes….

darwins view of life and education

darwins view: all living organisms are related through…

descent from a common ancestor

descedants of the ancestral organism spread to…

different habitats, those organisms adapt and get modifications(adaptations) tailored to their environmetns

traits change over generations causing…

populations to come different from their ancestors

explain the 3 points of darwinian view: descent with modification

-all living organisms are related through descent from a common ancestor

-descendants of the ancestral organism spread to diff habitats, which then those organisms adapt and get modifications(adaptations) tailored to their environments

-traits change over generations, causing populations to become different from their ancestors

What is the process of speciation

Development of NEW species

What is reproductive isolation

populations of the same species are SEPARATED

what does reproductive isolation lead to

speciation

why does reproductive isolation lead to speciation

they cant physically get together to mate/no viable offsprings

example of speciation learnt in class

darwins finches

what are the different types of speciation

geographical, behavioural, reproductive

what is geographical isolation

when a species gets sepereated to two different islands so they develop new traits due to mutation/natural selection over time to suit the different enviornments

what is behavioural isolation

things such as mating calls

what is reproductive isolation

dna mutations

what does the types of speciation lead to

speciation!

what is a gene pool

all available gene (alleles) in a population

are gene pools often unstable or stable

often stable for long periods of times (equilibrium)

can gene pools change

yes they can change suddenly, frequency of alleles can be altered because they favour some alleles over others

what is genetic drift

when an allele for trait becomes more/less common by chance (found mainly in small population

chance , luck

what is Gene Flow

the addition of a immigrant (new) alleles to a population

what is gradualism

evolutionary change that happens slowly over time

punctuated equilibrium

a long period of equilibrium followed by a rapid period of change

what can a punctuated occur from

isolation of population, dramatic change(meteor impact leads to mass extinction)

Non Random Mating

individuals with specific traits favoured for mating (e.g. male bird feathers

natural selection

favours “fitter” organisms to survive and reproduce! (e.g. peppered moth)

peppered moths is a good example of..

natural selection

Artificial Selection

human modifications of traits by selectively breeding individuals in a population

ex. certain dog breeds wouldnt survive without human care

Adaptations

result of natural selection

traits better suited to environments

features can allow for increased fitness

cant always be passed down to offspring

Heritable Traits

traits are linked to genetics of populations

changes to traits happens in DNA gene level

can always be passed on to offspring

Homologous

structures in different species that have similarities in traits resulting from a common ancestor, but may have different functions

Homologous example

human arms, whale flippers, bat wings, cat arms → all have similar bone structure but different functions

vestigial structures

body parts that have lost all or most of their original function signifying evolution

vestigial organs example

tailbones, appendix

Adaptive radiation

one species evolves into many different forms (species) making them look different but have similar internal structure

each adapted to diff environments or ecological niches

another term for adaptive radiation

divergent evolution

Analogous

structures similar in appearance and function but came from different ancestors

another term for analogous

convergent evolution

examples of analogous

bird and bat wing

fish and whale

fish and sharks

Comparative embryology

comparison of early stages of embryo development

shows similarities in early stages

examples of comparative embryology

ex. fish, chickens, humans all have similar features during early embryonic development concluding that they share a common ancestor

Molecular Homologies

all living things use DNA and RNA for genetic code

similarities in DNA, genes, proteins between species conclude that they share a common ancestor

example of Molecular Homologies

ex. humans and chimpanzees have very similar DNA concluding they have a common ancestor

endemic species

those that are found only in specific geographic areas (nowhere else)

provides evidence for reproductive isolation leading to speciation

ex. australia, galapagos islands

Fossil record

evolutionary transitions in fossil record

→ shows how organisms changed overtime from ancestral forms into newer forms → showing features from both

ex. link between dinosaurs and birds (anchaeopteryx)

microevolution

change on a small scale to a populations alleles or inherited traits

macroevolution

change on a larger scale above the species level, including formation of new species over long periods of time

definition of population

local group of individuals that can breed and produce viable offspring

gene pool

the genes population(all alleles and traits)

whats “Modern synthesis theory”

using darwins idea of natural selection and Mendels ideas about heritability, it used ideas to generate a complete view of evolutionary theory

sudden change (ex.fire/flood) dramatically reduces population size by change

Bottleneck -type of genetic drift

Founder effect -type of genetic drift

individuals (by chance) become isolated from the larger population and starts a new population, carrying only some of the original populations genetic variation

disruptive isolation

both extremes (almost opposite) favoured as traits

both black and white are favoured, grey is decreased in population

stabilizing selection

extremes are decreased, intermediate traits are seen

grey is being favoured as the emtremes (black and white) and decreased in #

directional selection

favours traits at one extreme

white is being favored as grey and black # decrease

Sexual selection

preference towards specific traits in mates

-more mating changes=passing favored trait onto male offspring

intrasexual selection

Competition between individuals of the same sex for access to mates.

→ stronger males more successful in mating

Allopatric Speciation

most common form of speciation

→ due to geographic isolation: gene flow stops between populations, genetic differences emerge, small populations=founder effect

Sympatric Speciation

super rare

Populations in same habitat become reproductively isolated

related to polyploidy (offspring born with twice the normal num. chromosomes)

sympatric speciation is most seen in

plants

Heterochrony

change in timing or rate of development of an organism compared to its ancestors

ex. animal may retain juvenile features into adulthood as development slows down/stops earlier

Allometric Growth -Example of heterochrony

When different body parts grow at different rates as organism develops

ex. human babys head is large compared to body → body grows faster then head as children develop

Paedomorphism -example of Heterochrony

when an adult organism retains physical features that were present in its juvenile stage

ex. mud puppy(salamandar) retains juvenile gills externally

reproductive isolation

biological factors that limit members of two species from producing viable fertile hybrids

Prezygotic barriers

limit 2 species from mating or prevent fertilization from occuring

temporal isolation

species reproduce at different times

behavioural isolation

species have different mating behaviours

mechanical isolation

morphological differences prevent mating

habitat isolation

species live in different habitats →rarely meet

gametic isolation

sperm and egg cannot fuse

Postzygotic barriers

occur after fertilization, reducing the survival or reproductive success of hybrid offspring

reduced hybrid viability

hybrid offspring do not survive or develop properly

reduced hybrid fertility

hybrid offspring survive but cannot reproduce

hybrid breakdown

first generation hybrids can reproduce but their offspring have reduced survival/ fertility

hybrid offspring

offspring produced when two individuals from different species reproduce with eachtoehr

POSTzygotic barriers

AFTER zygote forms -affrects hybrid offspring

PREzygotic barriers

before zygote forms -prevents mating/fertilization

invertebrates

animals without backbone

ex.insects, octopuses, worms, jellyfish, crabs

vertebrates

animal that has a backbone (spinal column)

ex. fish, amphibians/frogs, reptiles, birds, mammals

limitations of cladograms

1. no time components

2. traits that are selected are somewhat arbitrary

3. lacking evidence other then derived traits(no fossil evidence, molecular evidence)