lesson 5 - origin of species

Question 1

speciation

Answer 1

process by which one species splits into two species over time

ex: group of birds get split onto two islands, they adapt to their different environments, eventually the two groups change so much they can’t mate anymore - now they are two different species.

Question 2

microevolution

Answer 2

changes in allele frequency

ex: colour of bird changes

Question 3

macroevolution

Answer 3

evolutionary changes (development of new plants or animals)

Question 4

what is reproductive isolation?

Answer 4

biological barriers that prevent two species from producing fertile offspring
KEY: reproductive isolation is central to speciation

Question 5

pre zygotic barriers

Answer 5

barriers that occur before feritlization

Question 6

examples of pre zygotic barriers

Answer 6

habitat isolation, behavioural isolation, temporal isolation, mechanical isolation, and gametic isolation

Question 7

habitat isolation

Answer 7

one lives on water, one lives on land

Question 8

temporal isolation

Answer 8

one mates in summer and one mates in the winter

Question 9

behavioural isolation

Answer 9

different mating calls, signals, dances

Question 10

mechanical isolation

Answer 10

body parts do not fit together

Question 11

gametic isolation

Answer 11

can not form zygote

Question 12

what is allopatric speciation

Answer 12

speciation that occurs when geographic barriers isolate populations (separated by mountains)

Question 13

what is sympatric speciation?

Answer 13

speciation that occurs within the same geographic area

Question 14

define polyploidy

Answer 14

the presence of extra chromosomes sets due to cell division errors

normal number of chromosomes is 2n, but, polyploidy has division error and becomes 4n

Question 15

autopolyploid

Answer 15

all extra chromosomes come from the same species (not mixing with another species)

Question 16

allpolyploid

Answer 16

species with multiple sets of chromosomes derived from different species

Question 17

what are hybrid zones?

Answer 17

regions where two species meet and produce hybrids, with three possible outcomes: reinforcement, fusion, or stability

Question 18

what is another word for “hybrid”?

Answer 18

offspring

Question 19

two species become more different over time, reducing hybridization

Answer 19

reinforcement

Question 20

two species merge into one species

Answer 20

fusion

Question 21

hybrids keep being produced consistently, and the species that created the hybrids stay separate but still interact

Answer 21

stability

Question 22

what information do we need to classify a species concept?

Answer 22

morphological, biological, phylogenetic, ecological

Question 23

morphological species concept

Answer 23

defined by anatomical features

Question 24

ecological species concept

Answer 24

decide if animals are same or different based on where they live

Question 25

post zygotic barriers

Answer 25

problems that occur after fertilization

Question 26

reduced hybrid viability

Answer 26

baby does not grow up properly or dies before it can grow up

Question 27

reduced hybrid fertility

Answer 27

the baby grows up but it can not have babies of its own

Question 28

hybrid breakdown

Answer 28

hybrid can have babies, but their babies do not survive well or are weak

Question 29

two geographic modes of speciation

Answer 29

allopatric speciation and sympatric speciation

Question 30

allopatric speciation

Answer 30

populations are physically separated by barriers like tiers or mountains

Question 31

sympatric speciation

Answer 31

species evolves into new species without being physically separated (stop mating for other reasons)