Organisms and Ecosystems 1

species

a group of organisms with the same traits that can successfully breed and produce fertile offspring

variation

there is always some of this within a species

monozygotic twins

identical twins

variation

even monozygotic twins have this within their genes

distinct

when two species are able to create a hybrid, it suggests that the species are not

genus and species

what scientific name is made up of

binomial nomenclature

two name naming system creating the scientific name of a species that involves the genus and species of an organism

uppercase

in binomial nomenclature, is genus uppercase or lowercase

lowercase

in binomial nomenclature, is species uppercase or lowercase

domain kingdom phylum class order family genus species

taxonomic hierarchy

population

a group of organisms of the same species living in the same area

interbreed

what populations are unlikely to do if they live in different areas

divergence

can happen to species that no longer interbreed

speciation

the creation of a new species

gradual

pace of speciation

mitosis

how asexually reproducing organism create offspring

clones

how similar offspring of asexually reproducing organisms are to their parents

asexual reproduction means the clones cannot interbreed with each other, horizontal gene transfer

difficulty with biological species concept

genome sequencing

has revealed that separation between species is not always complete

conjugation

a temporary union of two bacteria for the purpose of DNA transfer

horizontal gene transfer

when genes are transferred between species

diploid

polyploidy of most animals

diploid

an organism that has two sets of chromosomes

chromosome number

what about chromosomes is unique to species

karyogram

karyotype

the number, size and shape of chromosomes in an organism

karyogram

an image showing the chromosomes of an organism

46

human number of single chromosomes

23

human number of paired chromosomes

48

chimpanzee number of single chromosomes

24

chimpanzee number of paired chromosomes

chromosomes 2A and 2B in chimpanzees joined together

how chromosome 2 in humans evolved

remnants of second centromere on human chromosome 2

proof of theory of how chromosome 2 in humans

chromosome

the entire base sequence of each of the DNA molecules

single-nucleotide polymorphism (SNP)

when a single nucleotide is replaced with another

SNP

much of what makes variations in a species

very diverse

genome size in eukaryotic organisms

similar

the closer related species are, the more their base sequences are

genome sequencing

offer insights into an organism's health, ancestry, and potential future medications

investigation of evolutionary relationships, re-classification of species

uses of genome sequencing

controlling/ preventing bacteria through there genome sequence, creating personalized medical treatments

potential uses of genome sequencing

dichotomous key

used to identify individual species of organisms using characteristics

DNA barcoding

a method of environmental sampling where a sample is taken from nature (such as soil) and put through a computer to identify what DNA is present in the soil and therefore what species are present there

organizing species better, gives a common language scientists can identify species by, allows us to quickly categorize organisms, allows us to see evolutionary relationships

need for classification of organisms

taxon

a classification group

taxa

plural of taxon

homologies

physical structures

physical structures

what organisms were originally group on

arbitrary

specificity of where to put organisms in taxa

species were originally classified by physical structures, arbitrary rules

challenges of hierarchy of taxa

genetic analysis

species are now classified using

uses genetic analysis, reflects on evolutionary relationships, can be used to make predictions about characteristics of organisms, helps us understand the diversity of life on Earth

advantages of current system of classification

clade

clade

a group of organisms that share traits and a common ancestor

DNA base sequence analysis or amino acid sequence analysis

best evidence to group species

morphological traits

physical characteristics of an organism

accumulation of sequence differences

estimation of when clades diverged from a common ancestor

mutations

what differences base sequences in amino acids and DNA come from

population size and intensity of selective pressure

why mutation rate can vary

molecular clock

differences in DNA and amino acid base sequences accumulate over time

mutation occurs at a constant rate

the assumption regarding the rate of mutation

can only give an estimate

how accurately the comparison of base sequences can give the time since 2 species diverged from a common ancestor

parsimony

the most likely explanation is usually the simplest one

the most likely one

the least complicated cladogram is usually

morphology only

if extinct species are featured in a cladogram, information must be given regarding whether the cladogram is

distant their relationship

the more nodes between species, the more

figwort

family reclassified with the arrival of genetic sequencing that caused five species to be relocated

bacteria, archaea, and eukaryotes

three domains

rRNA analysis

how two different domains consisting of bacteria and archaea were created

evolution

the passing on of heritable traits within a species in an attempt to evade natural selection over time

heritable

characteristics of an individual may change over time but this does not make the changes

yes

do populations evolve

no

do individuals evolve

natural selction

evolutionary force that acts on individuals

passed on

traits that are more favorable are

changes in the sequence of genes, the more closely related species are the more traits they share, homologous structures, analogous structures, selective breeding

evidence for evolution

HOX gene family

gene family that occurs in a wide variety of animal genomes

homologous structures

when organisms have body parts different in function but similar in structure

divergent evolution

what kind of evolution homologous structures are an example of

analogous structures

when organisms have body parts that are similar in function but different in structure

convergent evolution

what kind of evolution analogous structures are an example of

selective breeding

when humans mate individuals with desirable characteristics in order to produce more favorable selection

artificial selection

what selective breeding is an example of

they will evolve different ways

if two populations become separated so they cannot interbreed and natural selection acts differently on both of them, then

reproductive isolation

not being able to interbreed with members of a different species

differential selection

evolution acting differently on two different species

allopatric speciation

the formation of new species in populations that are geographically isolated from one another

sympatric speciation

the formation of new species in populations that live in the same geographic area

temporal isolation

reproductive isolation due to breeding at different times

behavioral isolation

reproductive isolation due to different styles of courting and mating

geographical isolation

reproductive isolation caused by species being separated by a geographical feature

temporal, behavioral, and geographical isolation

isolating mechanisms that lead to reproductive isolation

bonobo and chimpanzee speciation

famous example of allopatric speciation where a species was separated by the Congo river and neither side could cross the river to mate with the other species

adaptive radiation

an evolutionary pattern in which many species evolve from a single ancestral species in order to minimizes species competition so they can coexist

islands

where adaptive radiation usually occurs

hybridization

combining two different species to create a new one that is reproductively isolated from the parent species

prezygotic

before conception

postzygotic

after conception

behavioral isolation

prezygotic prevention of hybridization

reduce viability of the zygote, reduce viability of the young to live to adulthood, decrease fertility of the hybrid

postzygotic prevention of hybridization