Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/79

Click to flip

79 Cards in this Set

  • Front
  • Back
  • 3rd side (hint)
Evolution
-Genetic change in a lineage over time (generations)
-change in allele frequencies = evolution has occured
-first convincing case put forth by Charles Darwin ("father of evolution"
Natural Selection
survival of the fittest
-"fit"= the ability to survive AND reproduce
ie: goddamn British Peppered Moth (industrial melanism)
Artificial Selection
evolution due to an unnatural factor
ie: breeding of dogs
-cross breeding of plants to produce superior offspring
Vestigial Structures
structures (ie:bones) that have no funtionality
-supports the idea that all living organisms evolved from another structurally diff. ancestor
ie: whales have bones thought to be leftover leg bones
Charles Darwin
-Naturalist, sailed on HMS Beagle in 1831
-Galapagos Islands
-his book, Origin of Species, published 1859
Origin of Species
-written by Charles Darwin in 1859
-argued two main points:
1. Evolution explains the unity & diversity of life... descent w/modification
2. Natural Selection is the main cause of evolution (survival of the fittest)
*differential reproductive success leads to adaptation
Microevolution
evolution on a small scale
-a population is the smallest unit that can evolve
*individuals do not evolve
Speciation
the creation of a new species
-a new species is created with the evolution of reproductive barriers
Reproductive Barriers
any barrier that impedes two individuals from producing fertile hybrids
What are the two categories of Reproductive Barriers?
*prezygotic (zygote will not form)

*postzygotic (zygote forms, but does not survive)
Types of Speciation
1. Allopatric Speciation
2. Sympatric Speciation
Allopatric Speciation
a speciation event in which the initial block of gene flow is caused by a geographic barrier that physically isolates the populations
Sympatric Speciation
formation of a new species within the rage of the parental population
-no physical geographic barrier
-much less common than allopatric speciation
Macroevolution
Origin of taxonomic groups higher than the species level
-evolutionary change substantial enough to view its products as new genera, families or phyla
*Has a random component
What do Macroevolutionary Biologists study?
-major evolutionary changes
ie: bird feathers, insect wings
when did these features evolve?
-evolutionary trends (why certain changes came about over time in a specific species)
ie: extinctions and radiations
Pace of evolution
the rate at which evolution occurs...
consists of two theories
1. gradualism
2. punctuated equilibrium
theories
Gradualism
one of the theories of the pace of evolution
-change that slowly accumulates over time
Punctuated Equilibrium
one of the theories of the pace of evolution
- change consisting of periods of stasis, followed by periods of rapid change
Radiations
a period of time where many species evolve
-an increase in biodiversity over a relatively short period of time
-usually occurs after extinction
Ecology
the study of how organisms interact with each other and with their environment
-ecology drives evolution
Levels of Ecological Organization
-populations
-communities
-ecosystems
general... basic levels
Populations
groups of individuals of the same species living together in one area
Communities
populations of different species living together in one area
Ecosystems
communities and the non-living parts of the environment with which they interact
Population Structure
Key aspects:
Population Size
Population Density
Population Dispersion
Population Size
a count of the total number of individuals that exist
-Affects populations ability to survive
-small populations - more likely to go extinct
Population Density
Number of individuals per unit area
-low density can be a problem for that population (harder to come in contact w/each other in order to mate)
Population Dispersion
Spacing of individuals within the population
*Random, uniform or clumped
3 types
Clumped Dispersion
Clumped dispersion is when individuals aggregate in patches.
ie: schools of fish
Uniform Dispersion
uniform dispersion is when individuals are evenly spaced.
- usually due to territoriality
Random Dispersion
In random dispersion, the position of each individual is independent of the others.
Overall, dispersion depends on resource distribution.
Survivorship Curves
Graphical representation of the survivorship (opposite of mortality) at each age
Type I, Type II & Type III
definition and 3 types
Type I Survivorship Curve
increased risk of dying when old
ie: humans
Type II Survivorship Curve
equal chance of dying at all ages
ie: hydra
Type III Survivorship Curve
increased chance of dying when young
ie: shellfish (oysters, clams, etc.)
-due to lack of parental care
Biotic Potential
the rate a population would grow at with no limits
*represented by "r"
an intrinstic rate of increase
has to do with population growth
Two Models of Population Growth
1. Exponential Growth ( J-curve)
2. Logistic Growth (S-curve)
-growth rate slows as carrying capacity is reached
Carrying Capacity
populations eventually reach a limit to their growth
*number of individuals that the environment can support (represented by the letter "k")
has to do with population growth
Limits to Population Growth
-resource limitation (not enough food, etc)
-predation (get eaten, ha.)
Community Ecology
interactions among populations
Niche
-a species/population's place in the ecosystem
-total of all the ways an organism uses resources in its environment
-food consumption, space utilization, temp range, etc...
Community Ecology
Habitat
physical location of a species
-the environment in which it resides
Community Ecology
Definition of Competition
the struggle between organisms to utilize the same resource when the resource is limited
-niches overlap and resources are limited
Types of Competition & their definitions
1. Interference Competition
-"fighting" physical interaction between individuals

2. Exploitive Competition
- consuming shared resources (no physical interaction, one community uses up all the food, the other dies)
2 types
Interspecific competition
between individuals from different species
Intraspecific competition
between individuals from same species
Competitive exclusion
-no two species can occupy the same niche indefinitely
-one species will be outcompeted and may be driven to extinction locally
Interspecific competition
What can niche overlap lead to?
resource partitioning (results in species coexisting, territories for feeding)

-character displacement (species develop diff. traits to allow them to use diff resources, ie: galapagos finches)
there are two diff results
Predation
Predator uses prey for food
-prey evolves defenses, predator evolves adaptations to overcome (coevolution)…arms race
Plant defenses against herbivores:
morphological (physical structures) -thorns, spines, plant hairs
chemicals - secondary compounds
Animal defenses against predators:
-Behavioral defenses include fleeing, hiding, self-defense, noises, and mobbing.
-Camouflage includes cryptic coloration, deceptive markings.
Mechanical defenses include spines & shells.
Chemical defenses include odors and toxins – may get them from the plants they eat (ex: monarch butterfly & milkweed)
Aposematic coloration
is indicated by warning colors, and is sometimes associated with other defenses (toxins).
ie: poison dart frogs
Animal defenses against predators:
Batesian mimicry
is when a harmless species mimics a harmful one.
ie: certain species of caterpillar mimics a snake (behaviorally & physically)
Animal defenses against predators:
Müllerian mimicry
is where two or more unpalatable species resemble each other.
ie: yellow jackets, wasps, etc. all look similar, predators know not to eat anything that looks like them
Keystone species
-a species that regulates other species in a community
ie: sea stars pick off mussels in rocky intertidal zones, allow less dominant species to thrive there as well
*a community structure is greatly affected if keystone species are removed ie: kelp- sea urchins-sea otters-orcha
predation
Coevolution
refers to reciprocal evolutionary adaptations of two interacting species.
-When one species evolves, it exerts selective pressure on the other to evolve to continue the interaction.
Systematics
The study of biological diversity in an evolutionary context
-encompasses both taxonomy and phylogeny
Taxonomy
The science of the classification of organisms into species
-also to classify species into higher taxonomic levels
*Species that appear to be closely related are grouped into the same genus.
Taxonomic System
-classification system
Domain Eukarya
Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Primates
Family Hominidae
Genus Homo
species sapiens
did King Philip....
Phylogeny
Evolutionary history of a group
represented graphically in phylogenetic trees
*time goes from the bottom up
read from bottom up, NOT LEFT TO RIGHT
branch “length” = the number of changes
Monophyletic Group
- a single ancestor gave rise to all species in a particular taxon
phylogeny
Homology
= likeness due to common ancestry
Analogy
= likeness due to convergent evolution

ie: flippers on whales and penguins
Evidence used to reconstruct phylogenies on a molecular level
-Protein comparisons (since protein codes for DNA)
-DNA comparisons
DNA-DNA hybridization, restriction mapping, DNA sequencing
The rule of Parsimony
used when mapping phylogenies
-"simplest is best"
Cladistics
a school of taxonomy
-uses shared derived characteristics to classify organisms
concerned with branching order, not with morphological similarities
Kingdoms of Life
Archaebacteria
Eubacteria
Protista
Plantae
Fungi
Animalia
there are 6
Domains
(above kingdoms)
Domain Bacteria (Bacteria)
Domain Archaea (Archaebacteria)
Domain Eukarya (Eukaryotes)
there are 3
Kindom Archaebacteria
-one of the branches of Monera
-prokaryotic
-live in extreme enviroments (ie: hot springs, extreme cold, salty) as well as typical environments
-considered to be molecularly more similar to the eukaryotes
-very abundant
-important decomposers and symbionts
all characteristics
Kingdom Protista
-eukaryotic
-very diverse and controversial kingdom
-origianlly consisted of all unicellular eukaryotes
-now split into as many as 20 kingdoms
-characteristics used to classify protists: mode of locomotion, nutrition, overall body form, pigments etc.

ie: seaweed
Kingdom Plantae
-eukaryotic
-multicellular
-autotrophic
-cell walls present
Kingdom Fungi
-eukaryotic
-mostly multicellular (exception: yeast)
-heterotrophic (nonphotosynthetic)
-cell walls present
-decomposers, some cause disease
-acquire nutrients through absorption (digest outside the body)
Kingdom Animalia
-eukaryotic
-multicellular
-heterotrophic
-no cell walls
Kingdom Eubacteria
-one of the branches of Monera
-prokaryotic
-very abundant
- cell walls made of peptidoglycan (molecule)
-genome in nucleoid region
-single major chromosome (one double stranded DNA molecule forms ring)
-plasmids present
characteristics
Common shapes of Prokaryotes
cocci- round
bacilli- rod-shaped
helical- spiral shaped
3 distinct shapes
Endosymbiotic Theory
-theory that mitochondria & chloroplasts were once free living cells, taken in to form eukaryotic cells
Hyphae
-thin threads of tubular walls surrounding cell membranes & cytoplasm
-form an interwoven net called the mycelium
fungi body form
Mycelium
-an interwoven net of hyphae
-part of the fungi body
fungi body form
Fungi Reproduction
-spores are produced either sexually or asexually
-hyphae and spore nuclei are haploid
*except for a brief diploid stage that occurs during sexual reproduction
(opposite of human reproduction)