Evolution Flashcards
What is evolution
Changes are n types of organisms over a period of time
What are fossils
Some remnant of an organism that proved its existence
What can fossils be of
Imprints of bacteria, leaves, insects, pollen, or flower parts
Tools, pottery shards, bones, and cave drawings
What is relative dating
Fossil age
How does fossil age work
Oldest fossils are in the deepest sedimentary rock layers.
Younger layers hold newer more complex fossils
What is absolute dating be used to determine
A precise age in years
How does absolute dating work
Uses the decay of radio-isotopes, such as carbon 14
Once an organism dies, it no longer breathes so it stops receiving carbon 14
What is the half life of carbon 14
5730 yeas
How old are the oldest fossils
3 billion years old
What are comparative studies used for
To establish evolutionarily relationships between organisms
What is comparative anatomy
Comparing specific body structures
What is are analogous structures
Similar functions, but the structure is different
What are homologous structures
Similar structures but the function is different
What is are vestigial structures
Structures are reduced in size and gave no known functions
There resemble structures in other organisms
What is comparative embryology
The comparison of embryonic development
What is comparative cytology
Observing similarities in cell structures
In comparative embryology what does the more similar the development mean
The closer the relationship between the species
What do all cells have in common
Similar organelles that preform identical functions
What organelles do eukaryotic cells and prokaryotic cells have in common
Plasma membrane, cytoplasm, and ribosomes
What does comparative biochemistry compare
Similarities involving proteins, enzymes, and nucleic acids
Through what process to all organisms share genetic codes
Transcription and translation
What do all organisms carry out the same way
Cell respiration
What to all autotrophs carry out the same way
Photosynthesis
Who were the people who contributed support for evolution
James Hutton
Charles Lyell
Thomas Malthus
What did James Hutton do
Was a geologist
Studied age of the earth
Sedimentation of rocks occur over several millennium
What did Charles Lyell
Think
Geographical events must be explained in terms of process that are observable today.
What did Thomas Malthus do
Was an economist who thought that if population growth went unchecked would lead to starvation. He included disease, war, disaster, and famine
What was J B Lamarck’s theory
Stated that organisms can change their body structures over the course of a lifetime. Also the acquired traits could be passed to the offspring
What is an Atrophy structure
Structure decreases in mass with disuse
What is a hypertrophy structure
Structure increases in mass with use
What did August Weissman do
He disproved Lamarck’s theory of use and disuse. He used mice to do so over the course of 22 generations
What did Darwin do
Came up with theory of natural selection
What are the stages of natural selection
Overproduction Struggle for existence Natural selection Variation Speciation
What is overproduction
Organism produce more offspring than can survive
What is struggle for survival
There are limited resources available
What is natural selection
Differences between groups of organisms of one species
What is directional variation
Single phenotype is favoured causing the allele frequency to continuously shift in one direction
What is stabilizing variation
When intermediate states are favoured and extreme variations become less common
(Takes out extremes)
What is disrupted variation
When both extremes are favoured and intermediate stated become less common or lost.
(only extremes)
What is speciation
Creating new species
How does speciation works
After many generations that are involved with natural selection a population may be so different that the new population can no longer reproduce with the original species.
It involves isolation
What is isolation
Anything which prevents two groups in a species from interbreeding
What is geographic isolation
A population is divided by a natural barrier
What is reproductive isolation
The differences between the isolated groups become so great they can no longer interbreed
Can geographic isolation cause a speciation event
No. It can instigate a speciation event, but genetic changes are necessary to complete the process.
What is microevolution
A change in gene frequency within a population.
Is evolution on a small scale and can be observed over shorter periods of time.
What’s industrial melanism
Changes in the colours of a population as a result of human activity
What’s macroevolution
Long term changes that make a new species.
Over a long period of time
What are the genre patterns of evolution
Divergent evolution Convergent evolution Adaptive radiation Adaptions Symbiosis
What is divergent evolution
Different groups evolve from one ancestor
What’s convergent evolution
Two or more different groups evolve so that they resemble one another strongly
What is adaptive radiation
Organisms spread into new environments and become adapted through natural selection. An example of divergent evolution
What is an adaptation
An anatomical structure, physiological process, or behavioural trait of an organism that has evolved over a period of time by the process of natural selection. It increases the expected long term reproductive success of the organism.
What’s camouflage and mimicry
Adaptations that some animals use as protection from predators
What are camouflage
An animal that looks like something in its environment
What is mimicry
Use colours and markers to look like another animal
What is symbiosis
Two species live in close association with each other and at least one member of the pair benefits while the other can be harmed, benefits, or is neither harmed or benefits
What is mutualism
Both organisms benefit
What’s parasitism
One organism benefits while the other is harmed
What is commensalism
One organism benefits while the other is neither harmed or benefits
What’s the heterotrophs hypothesis
Suggests a probable sequence in which organisms appeared.
What are the stages of the heterotroph hypothesis
NO O2 was available on old earth
First organisms were were anaerobic heterotrophs and used water for food and release CO2 as a waste product
Next organisms used CO2 for food and were anaerobic autotrophs
Next organisms used O2 and were aerobic autotrophs
What’s gradualism
Evolution occurs slowly and continuously overtime
What’s punctuated equilibrium
Evolution can occur quickly and it can be followed by long periods of little or no change at all
What are population genetics
The study of the genes in an entire population at one time
What’s a population
All the members of s species in an area
What’s a gene pool
All the alleles within a population
What’s a gene frequency
Percent of alleles for one trait for one trait that are dominant or recessive
What’s an allele
Variation of a gene
What is the hardy Weinberg law
States that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences
What does p2 mean
Dominant allele
What does q mean
Recessive allele
What does P2 mean
Homozygous dominant
What does 2pq mean
Heterozygous
What does q2 mean
Homozygous
What 5 conditions must be met for the hardy
Weinberg law to be true
Large population No migration No mutations No natural selection Random mating
What’s a large population
In small populations, alleles might be lost by the death of a few individuals
What does no migration mean
Individuals may not migrate into or out of a population
Why can’t there be mutations
Mutations change the frequency of the alleles in the population
Why can’t there be natural selection
Each member of population must survive long enough to reproduce
Why must there be random mating
Each individual in a population must have an equal chance to reproduce
Why does the hardy Weinberg law not work
Mutations occur spontaneously
Reproduction is not random
Natural selection does not occur
Why does the failure of the hardy Weinberg law is a sign that evolution occurs.
There are changes in the allele frequencies
External factors change in frequency
