Chapter 18 Flashcards
1
Q
adaption
example: a platypus’s webbed feet are an adaption for swimming
A
heritable trait or behavior in an organism that aids in its survival and reproduction in its present environment
2
Q
What do mutations create in the DNA?
A
They create changes in the DNA
3
Q
When does evolution occur?
A
It occurs in generations, not the lifetime of an organism
4
Q
The scientific definition of evolution?
A
A change in the genetic composition of a population from generation to generation
5
Q
Aristotle
A
- Made the ladder of nature which is organisms based on observed traits, paced humans on the top of the ladder
6
Q
Carl Linnaeus
A
- Made the nested classification system, also known as taxonomy. Group similar species in increasing general categories.
- Created system for naming plants and aniamls, which is known as the binomial system.
7
Q
What is the species and domain of humans?
A
Homo Sapiens
8
Q
James Hutton
A
Hutton proposed that geological features are from slow continuous processes also known as gradualism
9
Q
Charles Lyell
A
Lyell expanded Hutton’s ideas and proposed that the same geological processes are happening today as in the past at the same rate, which is called uniformitarianism
10
Q
Erasmus Darwin
A
Wrote the idea that “forms minutes” slowyl acquired complexity over time. First person to form the theory of evoultion, his theory was that life revolves around a nautral ancestor
11
Q
What is a naturalist?
A
They are experts in natural history
12
Q
Lamarck
A
He came up with the idea the theory of adaptions, which linked evolution to adaption.
13
Q
Lamarckism example
A
When a giraffe’s daddy streched its neck longer to eeat, then passed this longer neck on.
14
Q
Theory of inhertiance
A
“Acquired” characteristics through “use and disuse”
- Parts of the body that are used regualry are strogner compared to the body parts that are barely used, they slow disingerate.
15
Q
What is Charles Darwin’s book called?
A
Origin of Species made in 1859
16
Q
Where did Charles Darwin go to research?
A
- He was invited on the HMS Beagle, and he travled to mostly South America and the Galapagos Islands
- He collected plants, wildlife, fossils, and observed species geographic locales and adpations
- studied local geology
17
Q
Alfred Wallace
A
He was the man who wrote a letter to Darwin to confrim his theories he had about evoultion, except he did his reasearch in the Malay Archipelgo
18
Q
What did Darwin’s book, Origin of Species basically explain
A
- Descent with modification: a phrase Darwin used to say that meant many species are descendants of ancestoral species
- Natural Selection: “survival of the fittest” is the reproduction of individuals with favorable genetic traits that survive environemntal change because of those traits, leading to evolutionary change and to greater adaption of the population to its local environment
19
Q
Who sketched the first phlogenetic tree?
A
Darwin did in 1837, a phylogenetic tree is a diagram used to reflect evolutionary relationships among organisms or gorups of organisms
20
Q
True or False: Acquired characteristics do not change our genetic combination
A
True
21
Q
“Natural Selecton is the mechanism for Evolution”- said Darwin, what did he observe to come up with this statement?
A
- Observation 1: Heritable variation exists in most species
- Observation 2: All species produce more offspirng than the environment can support (based on Maithus’ work)
- Observation 3: many offspirng die before maturity
22
Q
What are Darwin’s conclusions?
A
- Inference 1: unequal reproductive success among individuals, those with the best traits leave more offspring than others
- Inference 2: Those heritable, favorable traits (adpations) accumalte over vast time, matching the species to its environment
Example in slides: darker color beetles can escape the predators compared to the lighter ones
23
Q
Theory of evolution by natural selection
A
- explains both diversity and unity of life
- accounts for much of form and function
- can predict the outcome of environmental change
- genetic variation is essential for evolution by natural selection
24
Q
Evidence of evolution
A
- Fossil Record
- Homology
- Convergence
- Biogeography
- Molecular Biology
25
What does fossil record entail?
Many extinct species; no trilobites and dinosaurs exist today; happening ever since life started
Fossil intermediates: Seems to be an evolutionary transition between two groups of organisms
## Footnote
Example:
archaeopteryx (contains claws and teeth from dinosaurs, but also feathers and wings from birds)
Tiktaalik ( represents the transition from water to land; fishes and land vertbraes; bones in its fins were similar to human hands and wrist
26
What does Homology entail?
Homology means forms related by common ancestry
27
What are homologus structures?
Structures derived from a common ancestor (but may be modified)
## Footnote
Mammal forelimbs are homologus: the human, cat, bat, and whale
28
What are vestigial structures?
Remnants of ancestoral structures with no present adaptive function
## Footnote
Example: blind cave salamanders have eyes, wings on flightless birds, and levaes on cactus plants
29
What are homologus structures a result of?
Divergent Evolution
30
What does convergence entail?
Unrelated have similar adaptions (analogus structures) under similar environemntal conditions
Convergent evolution, which is when natural selection acted in the same way under the same conditions
Similar phenotypes will evolve in distantly related species due to the same evolutionary process
## Footnote
Example: torpedo shape for swimming, sharks, dolphins, and seals
31
What is a phenotype?
Set of observable characteristics of an organism
32
What is Biogeography entail?
It is the distribution of species that corresponds to geographic history
## Footnote
Example: isolated austrailian marsupials
33
How did Alfred Wallace contribute to biogeography?
He realized that deep ocean channel separating asian islands from austrailian islands explained great variation between similar habitats just a few miles apart
## Footnote
Example: endemic species on islans are similar to nearest mainland species, tree-dwelling iguana in SA and marine iguana in GI
34
What does endemic mean?
species not found anywhere else on the planet
35
Molecular Biology
- DNA analysis supports evolution
- closely related organisms have similar DNA
- Similar DNA sequences are the strongest evidence for evolution from a common ancestor
36
What are amino acids?
building blocks of proteins
37
defintion of species
A group of organisms that can interbreed and prdouce viable, fertile
38
Definiton of speciation
Formation of two species from one original species
39
How does a new species arrive?
When the genetics between two population become different enough that it prevents gene flow
40
Definition of gene flow
the movement of alleles across a species' range
41
Definition of allele
one of a number of alternate forms of DNA sequence at a particular genetic locus (the specific physical location of a gene)
Gene variations that arise from mutations
42
What is the morphological species concept?
Organisms that have significant morphological and anatomical differences are different species
Morphology means the study of size, shape, and structure of animals, plants, and mircobes, and the relationships of their constituent parts
## Footnote
Example: sorting birds into species based on their wingspans and beak size
43
What is the biological species concept?
Organisms that are reproductively isolated from each other are different species; they share the same gene pool (there is gene flow between two populations), and are reproductively isolated from other species by natural barriers
44
Definiton of gene pool
The sum of all the genes (including alleles) in a poopulation
45
46
What are gametes?
Egg and sperm; each have 1n (23); haploid
47
Embryo
multicellular
48
# Biological Reproductive Barriers: Pre-zygotic
What is temporal isolation?
Species have different breeding schedules
49
# Biological Reproductive Barriers: Pre-zygotic
What is habitat isolation?
members of the species move or are otherwise separated
50
# Biological Reproductive Barriers: Pre-zygotic
What is gamete isolation?
differences in gamete cells prevent fertilization
## Footnote
sperm of one species may not be able to fertilize eggs of another species (many of the gametic isolation proteins are on the sperm head and are called species-specific binding proteins. These binding proteins have to hit specific receptors on the zona pellucida (covering) of an egg.
51
# Biological Reproductive Barriers: Pre-zygotic
What is mechanical isolation?
When mating is impossible between different animal species because of the incompability of sexual organs
52
# Biological Reproductive Barriers: Pre-zygotic
What is behavioral isolation?
Certain actions or behaviors (or lack of them) impact reproduction; like courtship clues
53
# Biological reproductive barriers: Post-zygotic
What is reduced hybrid viability?
embry fails to develop or is weak
54
# Biological reproductive barriers: Post-zygotic
What is reduced hybrid fertility?
hybrid survives but is sterile (or is almost so)
55
# Biological reproductive barriers: Post-zygotic
What is hybrid breakdown?
2nd generation hybrids are feeable or sterile, the 1st gen works not the 2nd
56
Problems with the biological species concept?
- fossil species; trilobite
- asexual species; bacteria
- sometimes hybrids do happen (ex. girolar bear)
57
What is allopatric speciation?
## Footnote
allo= other; patric= homeland
How geographic separation makes a new species, it involves geographic isolation for a long time
58
What is Dispersal?
When a few members of a species move to a new geographical area
59
What is vicarance?
When a natural situation arises to physically divide organisms
## Footnote
Example: river forms a new branch erosion creating a new valley
60
What are the other barriers that cause allopatric speciation?
- changes (mutations) over time or natural selection etc. lead to the groups that are no longer reproductively compatible
- internal reproductive barrier
61
What are hybrid zones?
They are areas where two closely related species interact and interbreed
62
What does reinenforcement mean?
Hybrids are less fit than either purebred species. Reproductive barriers should be strong
63
What does Fusion mean?
Reproductive barriers weaken until the two species become one. Weak reproductive barriers
64
What is stability?
Fit hybrids continue to produced. Hybrids survive or reproduce better than either parent species. Barriers remain the same, and hybridization continues
65
What is adaptive radiation?
Process in which organisms diverisfy rapidly from an ancestral species into a multitude of new forms, due to changes in the environment making new resources, niches, etc. avaliable
66
What is sympatric speciation?
It occurs in the same geographical area, other factors create isolated gene pool, very rare process espieclly in animals.
67
Chromosomal errors in sympatric speciation
- Aneuploidy results when the gametes have too many or too few chromosomes due to nondisjunction during meiosis. The resulting offspring will have 2n+1 or 2n-1 chromosomes.
- Almost all plant hybrids are sterile and do not become new species
68
What is a polyploidy?
a cell or organism has an extra set or sets of chromosomes
69
What is autopolypoidy
The source of extra chromosomes of the same species
70
What is alloploidy?
The source of extra chromosomes from different species
71
What is an allopolyploid?
polyploidy formed between two related, but separate species
72
What is an aneuploidy?
condition of a cell having an extra chromosome or missing a chromosome for its species
73
# rates of speciation
What is gradual speciation?
species diverge gradually through time with small steps
74
# rates of speciation
What is punctuated equilibrium?
species exhibit a large change in a relatively short period of time followed by long period of stasis
75
what is the gradual speciation model?
model that shows how species diverge gradually over time in small steps
