Ch 24 Bio 2 Test 1

Front 1

Speciation

Back 1

Formation of a new species

Front 2

Anagenesis

Back 2

unbranched lineage, when a species changes so drastically over time that it becomes a different species and the anchestor ceases to exsit.

Front 3

Cladogenesis

Back 3

branched lineage, when 1 or more new species devolops from an anchestral species, but the ancestor cont. to exist, (Only cladogenesis can promote biological diversity by increasing the number of species.)

Front 4

Biological species concept

Back 4

(Mayr 1942) Species are groups of actually or potentially interbreeding populations, which are reproductivly isoloated from other such groups. defines a species as a population or group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring, but are unable to produce viable, fertile offspring with members of other populations

Front 5

Biological species concept EX.

Back 5

A businesswoman in Manhattan may be unlikely to meet a dairy farmer in Mongolia, but if the two should happen to get together, they could have viable babies that develop into fertile adults

Front 6

reproductive isolation (Isolation Factors)

Back 6

The existence of biological factors (barriers) that impede members of two species from producing viable, fertile hybrids. (Maintains Integrety of purety of species)

Front 7

Prezygotic Isolating factors (Barriers)(“before the zygote”)

Back 7

impede mating between species or hinder the fertilization of ova if members of different species attempt to mate.

Front 8

Postzygotic Isolating factors (barriers) (“after the zygote”)

Back 8

often prevent the hybrid zygote from developing into a viable, fertile adult.

Front 9

Limitations of the Biological Species Concept

Back 9

the number of species to which this concept can be usefully applied is limited. For example, there is no way to evaluate the reproductive isolation of fossils or asexual organisms such as prokaryotes.

Front 10

morphological species concept

Back 10

a group of organisms that differ in some anatomical respect from all other groups. characterizes a species by its body shape, size, and other structural features.

Front 11

Limitations morphological species concept

Back 11

Gray tree frog - Hyla versicolor and Hyla chrysocelis = look the same but have different calls (One disadvantage, however, is that this definition relies on subjective criteria; researchers may disagree on which structural features distinguish a species.)

Front 12

paleontological species concept

Back 12

focuses on morphologically discrete species known only from the fossil record. We are forced to distinguish many species in this way because there is little or no information about their mating capability.

Front 13

ecological species concept

Back 13

views a species in terms of its ecological niche, its role in a biological community. For example, two species of Galápagos finches may be similar in appearance but distinguishable based on what they eat. Unlike the biological species concept, this definition can accommodate asexual as well as sexual species.

Front 14

phylogenetic species concept

Back 14

defines a species as a set of organisms with a unique genetic history—that is, as one branch on the tree of life. Biologists trace the phylogenetic history of a species by comparing its physical characteristics or its molecular sequences with those of other organisms

Front 15

sibling species

Back 15

species that appear so similar that they cannot be distinguished on morphological grounds

Front 16

Two bird species in a forest are not known to interbreed. One species feeds and mates in the treetops and the other on the ground. But in captivity, the two species can interbreed and produce viable, fertile offspring. What type of reproductive barrier most likely keeps these species separate? Explain.

Back 16

Since the birds are known to breed successfully in captivity, the reproductive barrier in nature must be prezygotic. Given the species differences in habitat preference, the reproductive barrier is most likely to be habitat isolation.

Front 17

Which species concept can be used for both asexual and sexual species? b. Which can only be applied to sexual species? c. Which would be most useful for identifying species in the field?

Back 17

All species concepts except the biological species concept can be applied to both asexual and sexual species because they define species on the basis of characteristics other than ability to reproduce. b. The biological species concept can only be applied to extant sexual species. c. The easiest species concept to apply on a field trip would be the morphological species concept because it is based only on the appearance of the organism. Additional information about its ecological habits, evolutionary history, and reproduction are not required.

Front 18

Habitat or Ecological Isolation Mechanism

Back 18

When populations live in different areas and don't interact. Ectoparasites, basking turtle, cooters

Front 19

allopatric speciation

Back 19

gene flow is interrupted when a population is divided into geographically isolated subpopulations. (Devolpment of a new species as a result of a physical barrier)
EX. Lung Fishes - South Amer., Afr., Australla -3 genera, no gene flow, contential divide cause speciation Ex. - the water level in a lake may subside, resulting in smaller lakes that are home to separated populations

Front 20

Temporal Isolation

Back 20

Occurs when mating or flowering takes place at different times of the day or different seasons. Ex. Night Blooming Catus and Day blooming Catus

Front 21

Behavioral Isolation

Back 21

different species are not sexually attracted to each other, they might have different courtship rituals and/or displays. Ex. The dancing of flys to atract.

Front 22

Mechanical Isolation

Back 22

occurs when structrial differences in genotype or flowers prevent copopulation or pollen transfer. Ex. Size of flower one big one small brid will not fit in one. Ex. Huge dog 4ft and a little dog 12inch is not going to mate even though same species

Front 23

Gametic Isolation or Physological Isolation

Back 23

When male and female gametes fail to fuss or cannot survive in the female reproductive tract of another species. Ex. Starfish. Ex pH to low or high

Front 24

hybrid Inviability

Back 24

when hybrid zygotes don't devolpe to sexual maturity. Hybrid born alive but dies afterwards. (post zygotic)

Front 25

Hybrid sterility

Back 25

when hybrids dotn produce funtional gametes. (post zygotic)

Front 26

sympatric speciation

Back 26

speciation takes place in geographically overlapping populations. (Occurs when a sub population is reproductively isolated from its parent population.) Typically how plants evolve

Front 27

Non disjunction

Back 27

acident during cell division that results in extra set of chromosome. (

Front 28

Instantaneous Speciation

Back 28

by devolpment of polyploidy, or the production of a single indivdual that for varies reasons can't interbreed with members of the species to which parents belong.

Front 29

Punctuated Equilibrium

Back 29

(Niles Eldredge, Stephen Jay Gould) fast change, species remain unchanged (stasis) for long periods of time followed by a period of "rapid change"

Front 30

Darwin vs Punctuated Equilibrium
(Darwin vs Gould,Eldredge)

Back 30

small chages over a period of time vs stasis then rapid change