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

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


Play button


Play button




Click to flip

46 Cards in this Set

  • Front
  • Back
What is the current population of humans on earth?
6.4 billion and rising
How many new people are added every second?
3 people every second
What are the 3 patterns of dispersion?
random, clumped and uniform
What is an age structure?
An age structure divides into segments of 3 nations (# of individuals in each of several age categories)
What are the 3 components of age structure?
pre-reproductive, reproductive, post-reproductive
What is a type 1 survivorship curve?
Type I: Humans have a good change of living past age 50
Type 2 survivorship curve?
Type II: (linear line) mortality and survivorship are constant; age has no effect on survival or death (rodents, song birds, etc)
Type 3 survivorship curve?
Type III: inverse of type I; survivorship low in the beginning (anything that spawns; oysters, etc.)
What is the exponential growth model?
what would happen to population in ideal conditions (a quantity increasing by a fixed percentage of the total in each specified interval); G=rN
N=# of organisms (population size); G=growth; r= growth rate (dN/dt)
What is the logistic growth model?
shows how carrying capacity can affect population size
G=rN [(K-N)/K)]
What is carrying capacity?
the maximum number of individuals of a population that a given environment can sustain indefinitely (how many individuals can be supported in a habitat)
What is an ecological footpring?
How much average human takes up on the earth; average number is 24 acres
What can be done to decrease the ecological footprint?
Recycle, use other forms of transportation other than cars or airplanes, eat locally grown foods, less meat, use fuel efficient cars
About how many species live on earth?
1.7 million species have been described; 5-30 million are still out there unnamed
What species is most abundant?
insects 750,000 species named
What is the correct way to write a species name?
Canis familiaris
What did Linnaeus do?
(1707-1778) founder of taxonomy and binomial nomenclature (the two name, naming system)
In this order: Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species
theory of evolution in 1809
 Transformism
 Need-based
 Inheritance of acquired characteristicsexample/if you lose 2 fingers accidently, your children will be born without those 2 fingers; Arnold bodybuilding example
(1797-1875); Developed Uniformitarianism (1830), whatever forces that are on earth, they are uniform (volcanoes, earthquakes, etc.)
 Take home messages
• The earth is very old (much older than 6000 years accepted at the time via biblical reference)
• Slow and subtle processes over long periods of time can cause huge changes
(1726-1797) developed Gradualism (1795), the earth gradually, slowly changes
Had a unique ability to think along a geological time scale (if the earth were a year old; 2 ½ months prokaryotic life forms, 11 ½ months vertebrates develop, at 9:15 Homo sapiens evolve, I’ve been around about .13 seconds; Darwin’s observations; Most species produce more offspring than the environment can support; Environmental resources are limited; Most populations are stable in size; Individuals vary greatly in their characteristics (phenotype); This variation is heritable (genotype); Natural selection is the mechanism of evolution; 1859 published On the Origin of Species by Means of Natural Selection
also developed a theory of natural selection at the same time and collaborated with Darwin
first to test the abiotic synthesis hypothesis; he placed water, methane, hydrogen, and ammonia inside a reaction chamber. He kept the mixture circulating while zapping it with sparks to simulate lightning. In less than a week, amino acids and other small organic compounds had formed
What is biogeography?
Study of patterns of distribution of species.Animals of a given continent resemble the country more than any other country; Example/ Australia is dominated by marsupials
What is biological species?
is based on interfertility rather than physical similarity (the definition of species is based on its reproductive isolation)
What is a population?
localized group of individuals of the same species
What is a gene pool?
total sum of alleles in a population at one time. The genetic possibilities/diversity of a population
What is an allele?
an alternative form of a gene
What is natural selection?
a population of organisms that can change (adapt) over time as a result of individuals with heritable traits leaving more offspring than other individuals
What is genetic drift?
random changes in the gene pool of small population due to chance alone
What is stabilizing selection?
ex/ human birth weight; Intermediate forms of a trait in a population are favored and alleles for the extreme forms are not. Can counter mutation, gene flow, and genetic drift. It preserves most common phenotypes (pg 250)
What is directional selection?
selected force that forces in another direction
 Ex/ a new mutation that benefits individuals also may cause a directional shift (pg 248)
What is diversifying selection?
selecting against the average; Could eventually lead to 2 species; Occurs through error in meiosis usually
What is sexual selection?
a form of natural selection in which the genetic winners are the ones that outreproduce others of the population; Ex/ flashy colored male birds
What is the bottleneck effect?
a drastic reduction in population size brought about by severe pressure or a calamity.
What is the founder effect?
occurs when a new population arises from only a few individuals; Ex/ only a few fish are introduced into a lake; Ex/ only a few birds make it to an island
What is gene flow?
addition or removal of alleles due to individuals entering or leaving a population from another population through immigration and emigration; Ex/ blue jays keep genes flowing between separate oak populations
What is genetic variation a product of?
Sexual reproduction (genetic recombination); Mutations; Provide alternative alleles that may or may not be useful with changes in environment; This creates the substrate for adaptation to work with
What is allopatric speciation?
“geographical speciation”; Physical barrier that separates a species into two populations, until eventually they are so different that they cannot interbreed; Scale and type of movements, migrations, and dispersal can be key factors
What is sympatric speciation?
less common, form own new special species
What is exaptation?
evolutionary novelties are modified versions of older structures. Ex/ birds and flight; ex/ vocal cords lower down; can’t breathe and drink at the same time
What is paedomorphosis?
adults retain features that were juvenile in ancestors. Ex/ adult tadpole had characteristics (gills)
What is heterchrony?
ex/ head size and proportions. Head larger as child, something on our body that grows at different rates
What is homeosis?
spatial changes in developmental plan
How old is the earth?
4.55 billion years old
How old is the universe?
14-16 billion years old