Unit 1: Evolution Flashcards
Seven Characteristics of Life
Metabolism
Respond to Stimuli
Growth and Development
Reproduction
Evolve and adapt
Composed of cells
Homeostasis
all living organisms obtain and use energy to grow, develop, repair damage, and reproduce
homeostasis
What do producers do?
produce their own food (from CO2, H2O, and the sun) upon which the entire ecosystem depends
producer examples
plants and other photosynthetic organisms
What do consumers do?
obtain nutrients and energy from consuming the food made by producers
consumer examples
animals
process of building up complex substances from simpler substances
anabolism
examples of anabolism
building up cells and cellular components
photosynthesis
process of breaking down complex substances into simpler substances to release energy
catabolism
examples of catabolism
digestion
cellular respiration
all chemical reactions occurring within an organism
metabolism
anabolism + catabolism = ?
metabolism
something a living thing reacts to
stimuli
examples of stimuli
light
temperature
odor
sound
gravity
heat
water
pressure
to get bigger in size
growth
a change in the physical form or psychological make-up of an organism
development
the process of producing new organisms of the same type
reproduction
a single parent organism reproducing by itself
asexual reproduction
two different parent organisms contribute genetic information
involves the combination of male and female sex cells
sexual reproduction
what do all organisms pass along?
hereditary traits
carry hereditary information
are composed of DNA
genes
why do children resemble their parents?
hereditary!
changes DNA code and can be passed from generation to generation
mutations
how do living things evolve
through adaptation
how can the unity and diversity of organisms be explained?
through the mechanisms of evolution
a process that enables organisms to become better suited to their environment
adaptation
how do species obtain adaptation
through evolution over great periods of time
example of evolution and adaptation
desert plants have succulent, waxy leaves and stems to store water and reduce water loss, as well as prickly leaves
what are organized to form cells?
organic molecules
Life’s basic units of structure and function
cells
entire organism is made up of one single cell
unicellular organisms
examples of unicellular organisms
bacteria
protists
organism is made up of many cells
cells have specialized functions within the organism
multicellular organism
ability of an organism to maintain relatively constant internal conditions
homeostasis
examples of homeostasis
water balance
temperature regulation in humans
all _______ systems contribute to homeostasis
organ
animals could come from non-living sources
abiogenesis (spontaneous generation)
what does abiogenesis need for it to work
the atmosphere “active principle” needed to act on the non-living substance
did experiments with rotting meat to disprove abiogenesis
francesco redi
what did critics say about redi’s experiment?
lack of active principle
used meat broth flask to prove abiogenesis
john needham
why was john needham’s experiment faulty?
there was a loose seal
disproved needham’s experiment by boiling the flasks longer and sealing them shut, eventually doing timed boilings
lazzaro spallanzani
critiques of lazzaro spallanzani’s experiment
boiled too long
sealed the flask which means active principle wont work
used swan-necked flask to completely squash abiogenesis completely
louis pasteur
hypothesized that life began in the oceans on early earth between 3.9 to 3.5 billion years ago
alexander oparin
how is life created through alexander oparin’s hypothesis?
simple organic molecules containing carbon formed
energy from sun, lightning, and earth’s heat triggered chemical reactions to produce small organic molecules
molecules were organized by chance into complex organic molecules that are essential to life
complex organic molecules that are essential to life
carbohydrates, nucleic acids, proteins
attempted to prove alexander oparin’s hypothesis
stanley miller and harold urey
an experiment attempting to simulate early earth conditions
miller-urey experiment
proposed the endosymbiont theory
lynn margulis
explains origin of eukaryote cells and prokaryote cells
endosymbiont theory
explain endosymbiont theory
prokaryotes entered a host cell and the cells become mutually beneficial
prokaryotes eventually become organelles in the eukaryotic cell
evidence of endosymbiont theory
look at the organelles of mitochondia and chloroplasts
like prokaryotes they:
contain their own DNA
have ribosomes that resemble
reproduce by fission
observed “cells” in cork. coined the term cell
robert hook
credited with the first microscope development
anton van leeuwenhoek
concluded that all plants are made of cells (1838)
matthias schleiden
concluded that all animals are made of cells (1839)
theodore schwann
concluded that all cells come from pre-existing cells (1855)
rudolf virchow & robert remak
cell theory…go!
all living things are made up of cells
cells are the basic units of structure and function in an organism
new cells are produced from existing cells
ocular and objective lenses for compound maginification
uses light to pass through image
compound microscope
produces 3D images
uses electrons to pass through image
electrons have shorter wavelengths than light, therefore scatter less and create a clearer image
scanning electron microscope
produces 2D images
uses electrons to pass through image
transmission electron microscope
why is oil used with microscopes
the denser oil limited the scattering of light, providing a clear image
most powerful oil immersion lenses are capable of magnifying an image of _____
2000X
most oil immersion lenses magnify an image ______
1000X
what is required to increase magnification?
thicker lenses
what makes electron microscope have better magnification than light microscope
the 100000 times shorter wave length of the electrons is scattered less, producing sharper images
removes air molecules that absorb electrons and cause deflection
vacuum pump
what is the gold used for in a SEM
to produce a sharper image. specimen are often coated with a thin layer of it
power of ocular lens
10X
power of low objecive lens
4X
power of medium objective lens
10X
power of high objective lens
40X
regulates the amount of light passing through the specimen
diaphragm
movement under a microscope is…
opposite
what does the intial/primary magnification in a compound microscope
objective lens
what does the secondary magnification in a compound microscope
ocular lens
three domains that contain all living things
archae, bacteria, eukaryota
LUCA
last
universal
common
ancestor
shows branching patterns.
length of branch is meaningless.
order of branches shows organisms with common ancestors
cladograms
a group of organisms with a common ancestor
clade
shows branch order and lengths.
the length of branch represents the length of time organisms diverged in their lineage
phylogenetic trees
coined the term biology and invertebrae
suggested organisms acquire or lose traits based on how much they use them in their lives
jean baptiste lamarck
showed that increases in population will eventaully diminish the ability of the world to feed itself
more population = fewer resources
thomas robert malthus
came up with the theory of evolution by natural selection
worked on biogeography which provided evidence for natural selection
alfred russel wallace
proposed continents had once been connected — theory of continetal drift
identical fossil plants and animals had been discovered on opposite sides of the atlantic
Alfred wegner
Key author of the synthetic theory of evolution (humans genetically design DNA = manipulate DNA/changes in genetics); AKA Modern Synthesis of Evolution Theory
stated that evolution is defined as change in allele frequency within the gene pool
Theodosius Dobzhansky
Development of the endosymbiont theory of the origin of cells
Lynn margulis
Biologist who criticized sociobiology, offering explanations based on culture rather than on genetics and evolution
Created the theory of punctuated equilibrium
Stephen jay gould
From his study of ants, he surmised that what seems to be altruistic self-sacrifice may paradoxically promote genetic flourish “social behaviour has resulted from evolution”
E.O wilson
the process by which populations of living things change over a series of generations. Change over time
Evolution
Study of fossils
Paleontology
Represent species that have become extinct or organisms that have undergone very little change over long periods of time
fossils
parts of an organism that are most likely to be fossilized
teeth, shells, bones
some ways of fossilization
Deep freeze
Impression/imprints
Tracks made in soft mud
Fecal material
Entrapment and embedment in amber
Old tar pits
Cell cavities and intracellulaire spaces of the skeletal material of animals or plants are replaced with mineral material such as silica, calcite or iron compounds
Petrified fossil
type of rock that usually holds a lot of fossils
sendimentary rock
a relative time scale for dating rocks and fossils
Geological time scale
Eras in order from most recent to oldest
Cenozoic
Mesozoic
Paleozoic
Proterozoic
Archean
Era, period and epoch we live in
Cenozoic
Quarternary
Recent
Era of the dinosaurs
Mesozoic
Calculates the ages of rocks and fossils by measurements of the decay of radioactive isotopes more accurately
Radioactive dating
The time required for half of the atoms of radioactive substance to become disintegrated
Half-life
How old is earth?
4.5 billion years
When did life on earth first appear?
3.5 billion years
in an undisturbed sequence of rocks, the oldest rocks will be on the bottom, with successively younger rock on top of these
Law of superposition
A relative time scale that divides the earth history into a number of sections based on geological and biological events
Geological time scale
Comparing one thing to another to determine relative age. It doesn’t give an exact age
Relative dating
the study of similarities of embryos between different species
Embryology
Same origin but different functions
Homologous structures
Examples of homologous structures
Flipper of a seal, leg of a pig, wing of bat, human arm all have the same bone structures but different functions
Similar functions and appearance but not the same origin
Analogous structures
Examples of analogous structures
Wing of a bird and butterfly are both used for flight but their make up is different
Functional make up between organisms can be quite similar
Physiological evidence
Example of physiological evidence for evolution
Hormones in sheep and pigs can be injected into humans
Chemical makeup between organisms can be quite similar
Biochemical evidence for evolution
Example of biochemical evidence for evolution
Organisms in the same genes share similar DNA and proteins
Vestigial features:
Ridges of nose, appendix, tailbone
An organism that could be an evolutionary link between groups of different organisms
Intermediate species
Examples of intermediate species
Archaeopteryx
Platypus
One super continent
Pangea
Continents shifted apart. Explains why certain organisms are only found in specific continents
Continental drift
example of continental drift
Marsupials
Narrow strips of land that connected certain continents and this is why animals were able to migrate from one continent to another
Land bridges
Examples of land bridges
Moose are found in both Europe and North America
How animals got to the island
Island biogeography
Examples of island biogeography
Fly
Swim
Ice or land bridges
Rafting on vegetation or ice flows
Why rock formations and botany are similar between continents
Continental drift
Charles Darwin’s voyage:
At age 22 he joined the “HMS Beagle” as the ships naturalist in a 5 year voyage
What island did Darwin make a discovery
Galapagos Islands
Which bird did Darwin take note of
Finches
What did he notice about the birds?
There were 14 different species based on beak shapes
Beaks had adapted to feeding habits
What assumption did Charles Darwin make about the birds?
The different species had evolved from one common ancestor
Who concluded that species evolve by natural selection
Charles Darwin
Alfred Wallace
Thomas Malthus
Name of the book Charles Darwin published about natural selection
On the origin of species
4 principles about natural selection
Variation
Adaptation
Overproduction
Reproductive advantage / descent with modification
Heritable differences that exist in every population are the basis for natural selection
Variation
A trait that helps and organism survive and reproduce
Adaptation
The number of offspring produce by a species is greater than the number that can survive. Competition is key
Overproduction
Those that are best adapted to their environment are better able to compete, survive, and reproduce to pass on their traits
Reproductive advantage / descent with modification
Belgian blue is?
A type of cow
Selectively chosen trait was more muscle
Who was Secretariat?
A race horse who between 1973 and 1989 was used for breeding in the hopes that his genes would be passed on to future generations
Example of vegetables that resulted from selective breeding to produce what we have today.
Large, dark orange carrots.
Which bird has provided a number of different bird varieties
Pigeon
Which plant produces cabbage, broccoli, cauliflower, kale and kohlrabi through artificial selection
Wild mustard
Banana result of artificial selection
Less seeds than wild bananas
Corn result of artificial selection
Tesosinte is wild corn that humans have selectively bred to produce larger cobs with more kernels
Why are chicken artificially selected?
An 8 week growth period can vary drastically in the organisms size. Selecting the faster growing organism so that we can benefit from its products sooner.
What are dogs descendants of
Grey wolf (canis lupus)
Why were wolves artificially selected?
They would eat carcasses from hunting kills
Those that were aggressive were killed off and milder ones were not
Breeding the mild mannered dogs led to domesticated dogs
Size, skulls and coloration to create different varieties
Dangers of artificial selection:
Putting animals at health risk
Inability of some species to give birth naturally
Basset hound has problem with excessive skin
Daschund has a higher risk for paralysis
Boxer has difficulty breathing and one of the highest cancer rates
St. Bernard has large amount of skin and fur making them unable to work without becoming too hot
Faster horses means breeding for longer and thinner bones. Weaker and more susceptible to breaking.
a change in allele frequencies due to chance
Genetic drift
A trait of an organism
Allele
A genetic drift that occurs after an event greatly reduces the population
Bottleneck effect
Example of bottleneck effect
The overhunting of northern elephant seals during the 1800s.
By 1990s, population was 20 seals
These seals did not represent the genetic diversity of the original population. Now, population is 100000 seals after hunting ended. However, it has little genetic variation. Certain alleles have become fixed while others have become completely lost from the gene pool.
A genetic drift that occurs after a small number of individuals become isolated from population
The gene pools of these populations are often very different than longer populations
Founder effect
Example of founder effect
Bird carries seeds to a new location from a diverse flower population. These seeds “found” a new population.
Alleles for the specific flower increase in the new small population through genetic drift.
Effects of genetic drift
population loses genetic variation
alleles that are lethal in homozygous individuals may be carried by heterozygous individuals and hence, become more common in the gene pool due to chance alone.
The rise of two or more species from one existing species
Speciation
Gene flow between two populations stop for any reason
Isolation
When members of different populations can no longer mate successfully. Sometimes they are not physically able to mate with eachother. Other cases, they cannot produce offspring that survive and reproduce
Reproductive isolation
The final step of becoming separate species
Reproductive isolation
Example of reproductive isolation
Fruit flies with different alleles after migrating
Isolation caused by differences in courtship and mating behaviours
(chemical scents, courtship, dances of birds, courtship, songs of frogs, etc.)
Behavioural barriers of isolated populations
Example of behavioral isolation
Over 2000 species of fireflies are isolated, this way, male and female, fire flies produced patterns of flashes to attract mates of their own species.
Physical barriers that divide a population into two or more groups (rivers, mountains, lake, beds, etc. )
Geographic barriers
Example of geographic barriers
The formation of the Isthmus of Panama created a barrier for marine species. The isolated populations become genetically different. Snapping shrimp will snap at the opposite sides of the Isthmus instead of mating. They are classified as different species.
When timing prevents reproduction between populations. Reproductive periods may change to a different time of the year or a different part of the day. Leads to speciation.
Temporal barriers in isolated populations
Example of a temporal barrier
Two tree species that grow on the Monterey peninsula in California are very closely related however, they have different pollination periods. Monterey Pine – February. Bishop Pine – April.
What cannot be predicted?
Mutations
Genetic drift
Why is natural selection not random?
Acts on genetic diversity.
Evolution towards similar characteristics in unrelated species
Convergent evolution
Example of convergent evolution
Tail fin of fish and marine mammals. Sharks and dolphins - they are seperated by about 300 million years of evolution.
When closely related species evolve in different directions, they become increasingly different
Divergent evolution
Example of divergent evolution
Red fox and kit fox. Closely related, but different appearances as a result of adapting to different environments
The process in which two or more species evolve in response to changes in eachother
Coevolution
Example of coevolution
Relationship between ant and the acacia plant. Ant lives inside hollow thorn and protects acacia by sting any potential predators.
Species responds to pressure from the other through better adaptations over many generations
Evolutionary arms race
Example of evolutionary arms race
Plants producing defense chemicals to discourage herbivores from eating them. Natural selection then favours herbivores that can overcome the effects of the chemicals. After many generations most herbivores have some level of resistance and are again able to safely eat the plant. Natural Selection then Favour’s plants that have evolved even more potent chemicals.
Elimination of a species from earth
Often occurs when a species as a whole is unable to adapt to change in its environment
Extinction
Extinctions that occur continuously but at a low rate, rough at the same rate as speciation
Background extinction
Part of the cycle of life on earth
Background extinction
Example of background extinctions
Introduction of a new predator or decrease in food supply
More intense and rare extinctions
Occur at a global level
Destroy many species even entire orders or families
Mass extinctions
Example of mass extinctions
Catastrophic event such as ice age, asteroid impact
How many mass extinctions had there been
Fossil record confirms 5 in the past 600 million years
Episodes of speciation occur suddenly in geologic time and are followed by long periods of little evolutionary change
Punctuated equilibrium
Who proposed punctuated equilibrium?
Niles Eldridge and Stephen Jay Gould in 1972
The diversification of one ancestral species into many descendent species
Usually adapted to a wide range of environments
Adaptive radiation
Example of adaptive radiation
Radiation of mammals following the mass extinction of dinosaurs.they used to coexist. Once they were gone the once nocturnal, tiny and only eating insects mammals now have evolved to a variety of mammal species.
Selection and variation that happens more gradually
Population slowly, constantly, consistently changes.
Gradualism
Change comes in spurts
Period of very little change, then one or a few huge changes occur
Punctuated equilibrium
How does Punctuated equilibrium usually occur
Through helpful mutations in the genes
