Exam 4 Flashcards
What did Charles Darwin do for 5 years
a voyage through Southern Hemisphere
Who founded paleontology
Georges Cuvier
What is paleontology
the study of fossils
Catastrophism
explains appearance of new forms as replacing old forms due to local catastrophe
explains appearance of new forms as replacing old forms due to local catastrophe
catastrophism
not supported
people who were blinded in an accident would have blind children
people who were blinded in an accident would have blind children
not supported
modern genetics
pheonotypics changes accquired during the lifetime do not result in genetic changes that can passed to offspring
pheonotypic changes accquired during the lifetime do not result in genetic changes that can passed to offsprings
modern genetics
Biogeography
study of the distribution of life-forms on earth
study of the distribution of life-forms on earth
biogeography
speciation
formation of a new species- occured because the isolated population evovled independently of the mainland population
formation of a new species- occured because the isolated population evovled independently of the mainland population
speciation
fitness
reproductive success of an individual relative to other members of the population
reproductive success of an individual relative to other members of the population
fitness
artificial selection
humans choose particular traits
humans choose particular traits
artificial selection
what is the theory of evolution
that all living things have a common ancestor, but each is adapted to a particular way of life
archaeopteryx
fossils intermediate between reptiles and birds
adaptations
any characteristics that makes an organism more suited to its environment
any characteristics that makes an organisms more suited to its environment
adaptations
Vestigial structures
anatomial features that are fully developed in one group of organism but reduce and nonfunctional in other similar group.
most birds have well-developed wings; ostriches do not.
whales and snakes have remnants of hip bones and legs.
humans have a tailbone.
Presences explained by common descent hypothesis.
anatomial features that are fully developed in one group of organism but reduce and nonfunctional in other similar group.
most birds have well-developed wings; ostriches do not.
whales and snakes have remnants of hip bones and legs.
humans have a tailbone.
Presences explained by common descent hypothesis.
Vestigial structures
Homologous structure
anatomically similar structures are explainable by inheritance from a common ancestors.
all vertebrate forelimbs contains the same set of bones organized in similar ways despite dissimilar functions.
anatomically similar structures are explainable by inheritance from a common ancestors.
all vertebrate forelimbs contains the same set of bones organized in similar ways despite dissimilar functions.
homologous structure
analogous structures
structures serve the same function but are not constructed similarly- bird and insect wings
Homology
shared by vertebrates extends to their embryological development
shared by vertebrates extends to their embryological development
homology
what is Cytochrome c
a molecule used in the election transport chain of all organisms
a molecule used in the election transport chain of all organisms
Cytochrome c
Natural Selection
the process resulting in adaptation of a population to the biotic (living) and abiotic (nonlinving) environments
the process resulting in adaptation of a population to the biotic (living) and abiotic (nonliving) environments
Natural Selection
Variation
the members of a population differ from one another
Inheritance
many of these differences are heritable genetic differences
Increased fitness
individual that are better adapted to their environment are more likely to reproduce, and their fertile offspring will make up a greater population of the next generation
Stabilizing Selection
- Occurs when an intermediate phenotype is favored
- extreme phenotypes selected against
- individuals near the average favored
- most common form of selection b/c the average individual is well adapted to its environment
- swiss starlings lay four to five eggs b/c this method has the highest survival rate for their young
Directional Selection
- occurs when an extreme phenotype is favored
- distribution curve shifts in that direction
- can occurs when a population is adapting to a changing environment
- industrial melanism
- drug resistance in bacteria
- pesticide resistance in insects
- Malaria: Plasmodium becoming resistant to chloroquine and mosquitoes resistant to DDT
- Equus adapting from foret conditions to grassland conditions
Disruption Selection
- two or more extreme phenotypes are favored over any intermediate phenotype
- British land snails are found in fields and forest
- in fields, thrushes eat the snails with dark shell that lack light bands
- in forests, thrushes feeds mainly on snails with light-banded shells
Maintenance of variations
-populations always shows some genotypic variations
- population with limited variation may not be able to adapt to changing environmental conditions
-forces promoting variation constantly at work
>mutations, recombiination, independent assortment, and fertilization create new combinations
>gene flow
> natural selection favors certain phenotypes, but other remain
expressed
caused phenotypic differences
Balanced polymorphism
when natural selection favors the ratio of two or more phenotypes in generation after generation
what is malaria caused by
parasite that invades and destroys normal red blood cell
Microevolution
small measurable evolutionary changes within a population from generation to generation
gene pool
the various alleles at all the gene Ioci in all individuals of a population
What does Hardy-Weinberg principles states?
states that an eqilibrium of allele frequencies in a gene pool will remain in equilibrium as long as five conditions are met:
- no mutations
- no gene flow
- random mating
- no genetic drift
- no selection
Genetic Mutations
- ultimate source for allele differences
- without mutation there would be no new variations among members of a population for natural selection to act on
- adaptive value of mutation depends on current conditions
Gene flow
- also called gene migration
- movement of alleles among populations by migration of breeding individuals
- can increase variation within a population by introducing novel alleles from another population
- continued gene flow reduces differences among populations- can prevent speciation
Nonrandom mating
-selection of mate according to genotype or phenotype (not chance)
-assortative mating- tend to mate with individuals with the same phenotype
=>homozygotes increases in frequency
-sexual selection- favors characteristics that increase the likelihood of obtaining mates
Genetic drift
- refers to change in the allele frequencies of a gene pool due to chance
-allele frequencies “drift” over time depending on which members die, survive, reproduce
-more likely in small populations
-more likely to lose rare alleles
-two types:
=> bottleneck effect
=> founder effect
bottleneck effect
-species suffers a near extinction and only a few survivors go on to produce the next generations
=>infertility due to inbreeding
Founder effects
- rare alleles occur at a higher frequency in a population
- alleles carried by founders are dictated by chance alone
- Amish- 1 in 14 carries recessive allele for unusual form of dwarfism compared to 1 in 1000 in most population
photosynthesis
transforms solar energy into chemical energy of carbohydrates
producers
feed themselves and all of the consumers (most other living organisms on Earth
Chloroplast
-double membrane surrounds stroma
-third membrane forms thyrakoids
=>Grana- stacks
- thylakoid space
-chlorophyll and other pigments reside within thylakoid membrane
-pigments absorb solar energy
-carbon dioxide will be reduced in the stroma into carbohydrates
-glucose in the chief organic energy source for most organisms
light reaction
- occurs in thylakoid membrane
- chlorophyll absorbs solar energy and energizes electron
- water is oxidized, releasing electrons, hydrogen ions, and oxygen
- ATP produced in electron transport chain
Calvin cycle reactions
- occurs in stroma
- CO2 taken up
- ATP and NADPH used to reduce CO2 to a carbohydrate
Photosynthetic pigments
most photosynthesizing cells have chlorophylls and carotenoids
