Chp 25

Question 1

evolutionary changes that create new species and groups of species- concerns the diversity of organisms establishes over time through evolution and extinction of many species

Answer 1

macroevolution

Question 2

a group of organisms that maintains a distinctive set of attributes in nature

Answer 2

species

Question 3

have one or two traits that are somewhat different

Answer 3

subspecies

Question 4

usually members of a species adapted to a particular environment

Answer 4

ecotypes

Question 5

likley to be similar and considered the same species

Answer 5

short time

Question 6

more likely to show unequivocal differences

Answer 6

long time

Question 7

most common characteristics used to identify a species

Answer 7

morphological traits- based on physical characteristics
reproductive isolation- prevents one speceis from successfully interbreeding with other species..4 problems
molecular features- compare DNA sequences within genes and so on
ecological factors- variety of factors related to an organism’s habitat
species concepts- way to define the concept of a species and or provide an approach to distinguish one species from another

Question 8

species is a group of individuals whoe members have the potential to interbreed with one another in nature to produce viable, fertile offspring but cannot successfully interbreed with members of other species

Answer 8

biological species concept

Question 9

species should be defined based on the separate evolutionary lineages

Answer 9

evolutionary lineage concept

Question 10

each species occupies and ecological niche, which is the unique set of habitat resources that a species requires, as well as its influence on the environment and other species

Answer 10

ecological species concept

Question 11

mechanisms that prevent interbreeding between different species
these are consequences of genetic changes as species adapts to its environment

Answer 11

reproductive isolating mechanisms

Question 12

when 2 species do produce offspring

Answer 12

interspecies hybrid

Question 13

prevent formation of zygote

Answer 13

prezygotic barriers

Question 14

prezygotic barriers

Answer 14

habitat isolation- geographic barrier prevents contact
temporal isolation- reproduce at diff times of the day or year
behavioral isolation- important in mate choice
mechanical isolation- size or incompatible genitalia prevents mating
gametic isolation- gametes fail to unite successfullly

Question 15

block development of viable, fertile indiv

Answer 15

postzygotic barriers

Question 16

postzygotic barriers

Answer 16

less common in nature more costly in terms of energy and resources used
\hybrid inviability- fertilized egg cannot progress past an early embryo stage
hybrid sterility- interspecies hybrid viable but sterile
hybrid breakdown- hybrids viable and fertile but subsequent generations have genetic abnormalties

Question 17

formation of a new species (macroevolution)

Answer 17

speciation

Question 18

underlying cause of speciation

Answer 18

accumulation of genetic changes that ultimately promote enough differences so that we judge a population to constitute a unique species
1) abrupt events or 2) adaptation to diff ecological niches

Question 19

division of a species into 2 or more species

Answer 19

cladogenesis

Question 20

occurs when some members of a species become geographically seperated

Answer 20

allopatric speciation

Question 21

single species evolves into array of descendants that differ greatly in habitat, form or behavior

Answer 21

adaptive radiation

Question 22

zones where two populations can interbreed

Answer 22

hybrid zones

Question 23

occurs when members of a species that are within the same range diverge into two or more diff species even though there are no physical barrier to interbreeding

Answer 23

sympatric speciation

Question 24

organism has more than 2 sets of chromosomes (plants) can occur through nondisjunction

Answer 24

polyploidy

Question 25

chr from same species

Answer 25

autoploidy

Question 26

contain chromosomes from 2 or more diff species

Answer 26

alloploids

Question 27

certain females prefer males with one color pattern, while other females prefer males with a diff color pattern

Answer 27

sexual selection

Question 28

genetic changes leads to adaptions to the environ (diff niches) leads to reproductive isolation

Answer 28

summary of speciation

Question 29

each new species evolves continuously over long spans of time (neo-darwinism)
large phenotypic differences that produce new species are due to the accumulation of many small genetic changes

Answer 29

gradualism

Question 30

species in equilibrium for long periods and then short rapid bursts of changes

Answer 30

punctuated equilibrium

Question 31

compares the development of diff organisms in an attempt to understand ancestral relationships between organisms and the developmnetal mechanisms that bring about evolutionary change

Answer 31

EVO DEVO- evolutionary developmental biology

Question 32

development of a specific body pattern

Answer 32

pattern formation

Question 33

homeotic genes in vertbrates (encodes transcription factors that act as master control genes) proteins to direct the formation of particular regions of the body; usually in clusters on a part. chr.

Answer 33

hox genes

Question 34

increase in the number of hox genes may have led to

Answer 34

genetic complexity in body structures

Question 35

3 lines of evidence that hox genes are involved in evolution

Answer 35

hox genes are known to control fate of regions along the anteroposterior axis
general trend for more complex animals to have more hox genes and hox clusters
comparison of hox gene evolution and animal evolution bear striking parallels