Species and Speciation

Question 1

define speciation

Answer 1

origin of new species is at key point where microevol intersects macroevol

Question 2

What causes the formation of new species

Answer 2

repro isolation

Question 3

define species

Answer 3

repro compatible and cannot interbreed wit other pops

Question 4

what allows repro compatability

Answer 4

gene flow

Question 5

what causes repro incompatability

Answer 5

dec gene flow btwn pops so pops can diverge in allele freq by drift or NS or both and become repro isolated

Question 6

define repro isolation

Answer 6

bio factors/barriers that keep 2 species from producing viable and fertile offspring

Question 7

what is the bio species concept

Answer 7

groups of actually or potentially interbreeding pops which are repro isolated from other such groups and produces viable, fertile offspring…absence of gene flow between pops

Question 8

mechanisms of isolation

Answer 8

temporal/habitual, ethological/behavioral/sexual selection, mechanical, incompatability, hybrid inviability, hybrid sterility, hybrid breakdown

Question 9

which mechs of isolation are prezygotic

Answer 9

temporal/habitual, ethological/behavioral/sexual selection, mechanical, incompatibility

Question 10

which mechs of isolation are post-zygotic

Answer 10

hybrid inviability, hybrid sterility, hybrid breakdown

Question 11

which mechs of isolation are pre mating

Answer 11

temporal/habitual, ethological/behavioral/sexual selection

Question 12

which mechs are post mating(mating is attempted)

Answer 12

mechanical, incompatibility, hybrid inviability, hybrid sterility, hybrid breakdown

Question 13

habitat isolation

Answer 13

live in/on diff habitats
flies on apple vs flies on peach
potential mates, but do not meet

Question 14

temporal isolation

Answer 14

mate in diff seasons/time of day

potential mates but do not meet

Question 15

behavioral isolation

Answer 15

diff courtships shows…mates not chosen by females

Question 16

mechanical isolation

Answer 16

mating attempted, but physically can’t do it. 2 snails having diff chirality..genital openings don’t match up

Question 17

gametic isolation

Answer 17

incompatible egg and sperm molecularly

lock and key for species-species interaction

Question 18

define prezygotic barriers

Answer 18

impede mating, or hinder fert, or prevent attempted mating

Question 19

define postzygotic barriers

Answer 19

after a zygote is formed and fert is successful

Question 20

reduced hybrid viability

Answer 20

fert occurs but hybrid offspring is weak, sickly, can’t rlly survive well

Question 21

reduced hybrid fertility

Answer 21

vigorous but sterile

mules–> able to survivie fine but can’t mate with other mules

Question 22

hybrid breakdown

Answer 22

F1 hybrid are fine, but a backcross w/ organisms of 1 or other parental species causes recess alleles to be homozygous so less fit and sterile in F2
only affects F2 and later

Question 23

limitations of bio species concept

Answer 23

doesnt apply to fossils or asexual organisms

Question 24

morphological species concept

Answer 24

body shape and structural features w/o taking into account repro isolation
used for fossils alot
subjective

Question 25

ecological species concept

Answer 25

ecological niches, ex. polar bears and grizzlies

Question 26

phylogenetic species concept

Answer 26

defines species as smallest group of indiv that share a common ancestor forming 1 branch of the tree of life based on dna seq

Question 27

define sympatric speciation

Answer 27

subset of a pop forms a new species w/o geographic separation... still living in same region

Question 28

define allopatric speciation

Answer 28

more common | pop forms a new species while geographically isolated from its parent pop

Question 29

what are the 2 types of allopatric speciation

Answer 29

vicariance and dispersal patterns

Question 30

vicariance

Answer 30

barrier is being formed while speciation occurring | population preexists and occupied both areas before but smth like a road or river intervenes and separates the two areas

Question 31

dispersal

Answer 31

2 diff islands, 1 large pop on one island, some migrate to other island and distance acts as barrier if no more migration

Question 32

how is speciation maintained in sympatric pops

Answer 32

habitat diff polyploidy sexual selection

Question 33

habitat diff

Answer 33

apple maggot flies on domestic apples and on smaller native fruits...flies emerge and return to fruit they were born in

Question 34

autopolyploidy

Answer 34

both chromosomes from same species if all indiv in original pop are diploid, if cell div error occurs now tetraploid tetraploid produces diploid gametes and if gametes mate then form a new species that is 4n tetraploid isolated from diploid

Question 35

allopolyploidy

Answer 35

chromosome sets are derived from diff species fertile w/ each other but sterile to other species exhibit characteristics of both parents...a blend new species has diploid chromosome number equal to the sum of diploid chromosome number from each parent diploid 2n=6 + diploid 2n = 4 --> offspring 2n = 10 that is viable and fertile

Question 36

sexual selection

Answer 36

fish with red and blue backs

Question 37

define hybrid zones

Answer 37

regions where diff species w/ incomplete repro barriers mate and produce hybrids yellow and fire bellied toads enables us to study the process of speciation and mech of repro isolation repro barriers are incomplete

Question 38

when hybrids don’t become repro isolated from parent species....what are the 3 possible outcomes

Answer 38

1. reinforcement 2. fusion 3. stability

Question 39

reinforcement

Answer 39

NS favors indiv of 1 species to mate w/ indiv of same species....eventually limit hybrid zone keeps 2 distinct species

Question 40

fusion

Answer 40

speciation starts but stops | collapse of repro barrier

Question 41

stability

Answer 41

formation of stable hybrid zone occurring cont

Question 42

key points on speciation

Answer 42

bio species concept emaphsizes repro isolation speciation can take place w/ (allopatric) or w/o (sympatric) geographic separation hybrid zones reveal factors that cause repro isolation and insight in speciation process speciation can occur rapidly or slowly speciation can occur through mutation (polyploidy), drift (geo iso), and/or selection speciation can result from changes in few or many genes

Question 43

all organisms are related to each other via tree of life

Answer 43

trueeeee

Question 44

what does tempo of speciation depend on

Answer 44

lineage and env