Biology Exam #2

species

biological definition of ____ is a group of organisms that maintain a distinct set of attributes in nature.

Macroevolution

evolutionary changes that create new groups of species (aka speciation)

microevolution

evolutionary changes to a population gene pool

mechanism

microevolution is a _______ of macroevolution

the species concept

different ways to define a species

1.4 million

Estimated/hypothesized number of characterized species (1990) 1-100 million uncharacterized

prokaryotic

1-6 billion species on planet earth, they are mostly ________

phylogenetic species concept

members of a single species are identified by a unique combination of characteristics.

morphological species concept

if two individuals are different then they belong to different species (championed by Caroleus Linnaeus)

Flawed

The classification concepts may be _____ because where do we draw the line between same species and different ones.

Biological species concept

One or more populations of organisms whose members interbreed with each other to produce fertile offspring and do not interbreed with members of other species. (concept used in biology)

two criteria

_________ of Biological species concept

A. species have to be able to mate and produce viable offspring

B. production of hybrids (offspring of 2 diff species) do not count

No

do hybrids get scientific names

plants

Hybridization is very very rare in animals and more common in ______

Evolutionary Species concept

A species is derived from a single lineage that is distinct from other lineages and has its own evolutionary tendencies and historical fate.

Fossil records

sometimes difficult to identify species lineage due to inconsistent _______ ______

Molecular Clock

can use _____ ______ to fill in the gaps that the inconsistent fossil record leaves.

ecological species concept

Species are defined by the ecological niche (set of requirements needed to stay alive) they fill. most helpful in distinguishing bacterial species that do not reproduce sexually. individuals that compete with eachother are likely to be of the same species.

red queen

_________ hypothesis: species evolve in response to other species, evolve or die.

reproductive isolation

have to have mechanisms in place to maintain unique genetic distinctiveness

prezygotic mechanisms

prevent the formation of a zygote, no fertilization no individual

habitat isolation

occurs when a geographical barrier blocks populations from eachother

temporal isolation

differences in timing of mating season, mating in the fall v.s. mating in the spring

behavioral isolation

differences in mating and or courtship behavior ensures that reproduction between species does not occur.

mechanical isolation

also called disjunction is anatomical differences between species stop copulation from occurring, genitallia do not match up.

gametic isolation

gametes will not unite to form a zygote. body rejects sperm that is from other species.

post zygotic

isolating mechanisms that prevent gene flow once fertilization has already occurred.

hybrid inviability

zygote is formed but mitotic conditions are not met, therefore, the individual does not form an example of post-zygotic isolating mechanisms and an interspecific hybrid

hybrid sterility

the hybrids that are produced are sterile ex:mule, example of post zygotic isolating mechanism, is a type of interspecific hybrid

hybrid breakdown

produces hybrids that are partially fertile, however their offspring are at a disadvantage due to physical differences between species chromosomes. think developmental abnormities. examples can be found in corn or cotton plants.

mechanisms for how new species

2 proposed ______ ___ ____ ___ _____ form:

1. Species evolve as a consequence of adaptations to different ecological niches. (darwin’s finches and the shape of beak they had)

2. sexually reproducing organisms arise via reproductive isolation. ( if pop. A and pop. B of the same species can never meet, they will go down different evolutionary pathways)

Both of these things can happen at the same time

Anagenesis

when one species turns into another species via selective pressure. species A is gone and species B now exists instead.

cladogenesis

one species branches in a multitude of ways to produce new species. Species A evolved into new species while continuing to exist.

Allopatric

geographic isolation can promote_______ speciation

allopatric speciation

populations that are separated by geographical barriers are under different selective pressures caused by things like mountains flattening (slow change) or icebergs collapsing (fast change) example of this is the pork fish.

founder effect

_____ _____ can also lead to allopatric speciation or adaptive radiation

adaptive radiation

when a founder starts a new population there will be rapid diversification of one ancestral species to many new species, the founder effect leads to this. example Hawaiian honeycreepers (plant)

hybridization

can also occur if reproductive isolation between two populations is incomplete.

hybrid zones

areas where the geographical isolation of two different species overlap . reproductive isolation breaks down here and creates hybrid swarms. hybrid swarms occur in areas where pop A and pop B can meet.

sympatric speciation

“same country” speciation without geographic isolation (occurs often in the plant kingdom). can occur suddenly and it is relatively common in plants via altercations in chromosome numbers. (miotic condition)

autopolyploidy

polyploids with multiple chromosome sets from a single species. 1 parent species, happens due to miotic error.

tetrapolidy

a chromosome doubling.

allopolypoidy

arises from different species. 2 different parent species but they are similar.

Taxonomy

the branch of biology that is concerned with naming and classifying all living things and extinct organims

15,000

discovering ______ new species a year so we need to classify them.

Carolus Linnaeus

credited with inventing binomial nomenclature ( two names) wrote Species Plantarum, which catalogs all of the world’s plants. also published systema naturae; 10 volumes based on hirachry

polynomial

naming system, prior to Linnaeus a Latin naming system was used that described species an long sentences that described the organism.

binomial nomenclature

each name consists of two parts ( all names are latin)

generic name

refers to a group of organisms that are closely related to each other (genus)

species name

specific epithet (characterizing name) that tells you exactly what species it modifies. ( acts like an adjective)

latin, underlined, capitalized, genus

rules of binomial nomenclature

1. all names are ____ names

2. scientific names are always _______ and captialzed and species are lowercase ( most of the time)

3. generic names are _____ and species are lowercase ( most of the time)

4. note plural forms of phylum, ____ , and species

most , least

domain is the ____ inclusive and the species is the ___ inclusive

classification system

(biggest) domain, kingdom, phylum, class, order, family, genus, species. (smallest)

Plantae, Animalia

350 BC to mid 19th century —> organisms were divided into 2 kingdoms ______ & _____

Protista

1866 —> earns Haeckel recognized kingdom _______ ( now have 3 kingdoms)

Eukaryotic, Prokaryotic

1937 —> Edouard Chatton classified organisms as ________ / _______

monara, fungi

1969 —> R.H. Whittaker added two new kingdoms _____ & _____

Bacteria, Archaea, and Eurkarya

late 1970s carl woese proposes six kingdoms to be classified into 3 domains ______, _______, & _______

protista, fungi, plantae, and animalia

domain eukarya has 4 kingdoms, name them:

Bacteria, archaea

domains archaea and bacteria have kingdoms ___ & ____ under them

common characteristics 3 domains:

• all from a shared common ancestor

• DNA is the genetic material

• all species use the same genetic code

• mRNA encodes the information to produce proteins

• tRNA and ribosomes are necessary to produce proteins

• certain basic metabolic pathways are shared by all living organisms

Archaea, Eukarya

similarities between _____ and _____

• initiator tRNA methionine

• promoters of structural genes - ‘TATA’

Bacteria, Achaea

similarities between ______ and ______

• circular DNA

• chromosome segregation by fission

• no protein coding

• 70s ribosomes

• has operons

• does not have organelles

bacteria, eukarya

similarities between ______ and ______

• membrane lipids and ester-linked

zoological nomenclature

animal species are named by using the international code of ______ __________ (1758)

botanical nomenclature

plants are named using the international code of ______ _______ (1753) published with species planatrum also governs the naming of fungi and cyanobacteria

nomenclature of bacteria

bacteria are named using the international code of _____ __ _______ (1980)

protists

some protists are named using the plant nomenclature v.s. bacteria, though the international society of _______ want to name them. (1947-2005)

systematics

the study of biological diversity and evolutionary relationships

reconstruct phylogenetic trees

goal of systematics is to _______ _______ _____

monophyletetic

single common ancestor

paraphyletic

contains members that share the same common ancestor but not all descendants are in the same group

polyphyletic

group includes species with different ancestors

assumptions about phylogenetic trees

• evolution is a linear process

• evolutionary novelties arose once and obey the principle of parsoimy

• we know characteristics are homologous (same ancestor diff functions)

  • molecular clock is constant, know when mutations will occur

principle of parsimony

evolution takes place with the least amount of steps, more parsimonious trees are usually the most correct

shared derived characteristics

traits that are found in 2+ taxa that first appeared in their most common recent ancestor

shared primative characteristics

traits that are found in 2+ taxa that were present in distant ancestors

horizontal gene transfer

also called lateral : bacteria gave rise to mitchocondria and chloroplasts; aka traits are shared between groups

molecular systematics

______ ______ is changing our view of taxonomy; finding major mistakes in Linnaean classification and reclassifying.

systematics

the science of _______ is a constantly a “evolving” science that is based on new evidence that appears constantly