Test concepts Flashcards
5 principles of natural selection
1] variation exists within population
2] some variations favor the survival of an organism
3] overpopulation leads to competition
4] survivors may pass down favorable traits
5] long period of time allow for small changes to accumulate & contribute to survival adaptation
Charles Darwin + his voyage
English naturalist that proposed the theory of natural selection
His voyage on the HMS Beagle to the Galápagos Islands suggested that species were related but varied differently after being isolated on different islands
Principle of use/disuse
States that the part that is used more is more accentuated and the part not used becomes less defined and may ultimately disappear
Catasrophism
Sudden death of certain species from a natural disaster and new species move in
Lamarck
Parts adapt to suit their circumstances and in then pass those certain adaptations down to their offspring
- wrong because there is not a 100% chance they will pass down the trait
Fossil record
Collective record of the earths organisms
- showed how certain organisms and structures changed over time
Major influences on Darwin
- Lyell- principles of geology
- Malthus- essay on human population
- Voyage on HMS Beagle
- Collected specimens/domestic breeding
Lamarck’s idea of inheritance of acquired traits
Species will adapt and then pass on those traits to their offspring
B/w theory and hypothesis
Theory- collection of proven hypothesis
Micro evolution
Changes/varieties within a given type
Macro evolution
Evolutionary change on a grand scale
- apes to humans
Biogeography
Distribution of modern organisms and fossils support descent with modification
Anatomy
Studies of structures after birth
Homologous structures
Different organisms share similar body parts/structures of a common ancestor
Results from DE
Divergent evolution
Individuals of a certain species may respond in different ways to selective environmental pressures causing then to vary in natural selection
Analogous structures
Similar structures in organisms that had a different ancestry
- result if CE
Convergent evolution
Unrelated ancestral lines exhibit similar evolutionary changes caused by environmental selective pressures
- results in similar body plans/structures
Vestigial structures
Organs that don’t have an fund took in an organism but did have function in that organism’s ancestors
Taxonomic levels
KINGDOM PHYLUM CLASS ORDER FAMILY GENUS SPECIES
Artificial selection
Selective breeding
If done consistently the individual Witt the favored traits will eventually outnumber the others
Prezygotic isolating mechanisms
Prevent formation of a zygote
Temporal isolation
Species have different breeding seasons
Geographic isolation
Species physically separated
- no opportunity to hybrid
Ecological isolation
2 species in the same area but different portions of habitats
- do not encounter each other
Behavioral isolation
Courtship and mating rituals differ and keep species distinct
Mechanical isolation
Structural differences prevent mating
Gamete incompatibility
Union of gametes may be prevented
- if gametes fail to attract one another or function properly
Postzygotic isolating mechanisms
Prevent proper development of functioning of zygotes after they are formed
Post IMechanisms
- developmental problems
- reduced fitness
- reduced fertility
5 assumptions for hardy Weinburg
- no mutation
- no input of new alleles
- large population size [100]
- random mating
- no natural selection
Hardy Weinberg
P+Q=1 then (p+q)^2 = p^2 +2pq + q^2
Directional selection
Selection against one phenotypic extreme
Stabilizing election
Selection against both phenotypic extremes
•most common type of selection b/c it is associated w/ the adaption to the environment
Disruptive selection
Selection for both phenotypic extreme
•most responsible for divergent evolution
•process that leads to speciation
Bottleneck effect
When an event or a catastrophe drastically reduces the # of organisms in a population
•variations and allele frequency may be reduced
•severe reduction in total genetic diversity of the original gene pool
Founder effect
Combinations of alleles occur at a higher frequency in a population that has been isolated from a large population
Gradualism
Slow steady change over time
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/Punctuated equilibrium
Steady periods w/ great changes
[natural catastrophe]
\_\_\_ | \_\_\_ |
Hominid characteristics
•bipedal [foramen magnum]
•skull attaches inferiorly
-spinal cord is more curved and exits from the bottom of the skull
•broader bowl-shaped pelvis
•lower limbs are longer than the upper limbs
•spine S-shaped
•femur angled in
•absent sagital crest
•high cranial capacity
•small canine teeth
•absent brow ridgePongid characteristics
•evolved walking knuckle-walking •spinal cord exits posteriorly -skull attaches posteriorly •long narrow pelvis •upper and lower limbs both bear the body's weight •walk on all fours •spine slightly surged •very prominent sagital crest •lower cranial capacity •large canine teeth •prominent brow ridge Tetrapods [foramen magnum]
Mutualism
Both organisms benefit
Commensalism
One organism benefits
One organism is unaffected
Parasitism
One organism benefits
One organism is harmed
Predation
One organism benefits
One organism is killed
Timeline of human evolution
A A R hE H nC S
A. Afarensis
A. Africanus
H. Rudolfensis - H. Habilis
H. Erectus
H. Heidelborgensis
H. Sapien cromagnum
- H. Neanderthal
H. Sapien Sapien
