Darwin And evolution Flashcards
What were Darwins three observations
- species varied globally
- species varied locally
- species varied over time (fossils)
What was Darwins most famous stop
The Galapagos islands
What did Darwin notice about the land tortoises in Galapagos islands
On each island they had different shells
What did Darwin notice what’s different in the finches on the Galápagos Islands
They had different beaks
What is Darwins influence on people’s view
The fossil record had changed most people’s views that the world was only a few thousand years old and unchanged
Who is James Hutton
He propose that the earth is shaped by geological forces that occur slowly (gradualism)
What are some examples of gradualism
Mountains weathering away and the settlement from the mountain forming a new mountain
Who was Thomas Malthus
An English economist that wrote a book stating that babies are being born faster than people were dying
What did Thomas Malthus predict
That if the birthrates continued we would run out of resources
What is carrying capacity
The max number of individuals that a population can support
-Darwin believed this applied to animals and plants
Who was Jean Baptiste Lamark
He developed a hypothesis that acquired traits could be passed from parent to offspring
What is use and disuse
If a draft reaches into a tree, it’s neck will grow longer
Who was Charles Lyell
You wrote the principles of geology
What unifomatarianism
Must explain past events with processes we can observe now
-these events caused the earth to change gradually more overtime
What are two things Darwin learned from these men
If the earth changes the living things might change as well
If living things do change, it will take a long time
Who was Alfred Wallace
He sent Darwin a report explaining evolution that was nearly identical to Darwins theory
What was the origin of species
- A book published by Darwin which was his theory of evolution
- He wrote that organisms change over time as a result of natural selection
- he knew about artificial selection
What are two things required for natural selection
No two organisms are exactly the same and no to organisms are equal
What are adaptations
Any heritable characteristics that allows the organism to survive and reproduce
What is dissent with modification
The idea that each living species has descended with changes from other species overtimeand that they are linked by a common ancestor
What are the three types of natural selection
Stabilizing selection, directional selection, and disruptive selection
What is stabilizing selection
When the environment chooses the intermediate form of a trait
-birth rate
What is directional selection
When the environment chooses one extreme form of a trait
-woodpecker beak length
What is disruptive selection
When the environment Tuesday is both extremes of a trait
-lizard body size
What is the Hardy Weinberg principle
It assumes that evolution is not occurring (genetic equilibrium)
What are the conditions that must be met in order to be in genetic equilibrium
- Random mating
- large population
- no migration
- no natural selection
- no mutations
What is the equation for the Hardy Weinberg principle
P^2+2pq+q^2=1
P+Q=1
What do all the letters mean in the Hardy Weinberg principle
P=Frequency of allele A Q=frequency of allele a P^2=Frequency of individual AA Q^2=Frequency of individual aa 2PQ=Frequency of individual Aa
What is a mutation
It must occur in a germ cell and is spontaneous
Genetic drift
- When chance events alter allele frequency
- AKA bottleneck effect–
- effects smaller populations because of the gene pool being small
What is the founder affect
After disaster occurs, the few remaining are the founders
- founders rebuild ovulation
- founders survive by chance
Migration
Gene flow-genes flooring in and out of a population
One evidence of evolution
Fossil record
Geographic distribution
Pangaea
Vestigial organs
Structures that serve no function I E the appendix
Homologous structures
Structures that have different mature forms but develop from the same embryonic tissue
Analogous structures
Similar function but did not evolved from a common ancestor
Evolve due to similar habits
I.e. wings
Embryology
Swag
Molecular biology
Similar DNA sequences suggest evolutionary relationships
I.e hox genes
What is speciation
The process by which a new species is formed due to reproductive isolation
Behavioral isolation
- courtship rituals keep from interbreeding
- ex frog sex
Geographic isolation
Separated by physical barrier
Temporal isolation
- reproducing at different times
- ex nocturnal and diyurnal or wood frogs and leopard frogs
Adaptive radiation
Occur when a single species evolve into many different species do to natural selection
Derwin’s finches
Divergent evolution
Convergent evolution
- unrelated species evolve to look similar due to similar habits
- EX dolphins and sharks
Co-evolution
Two species evolve in response to changes in each other overtime
Ex. Flowers and pollinators or flower toxins and insects
What is gradualism
Species evolve at a slow steady rate overtime
What is punctuated equilibrium
Species stay the same for a long period of time and then undergo rapid change
Molecular evolution
- molecular clock: uses mutation rates in DNA sequences to estimate the time that to species have been evolving independently
- neutral mutations accumulate in DNA overtime at about the same rate and all species
- by comparing DNA sequences of two species, we can estimate when they shared a common ancestor
Where did all these genes come from
- copying jeans that can occur due to unequal swapping of DNA during crossing over
- modification of existing genes
Hox genes in evolution
- they determine which part of the embryo will become what
- can result in changes in adult species
- ex insects and crustaceans
Who is Charles Darwin
He is a man that took a job as a ship naturalist on the HMS Beagle for five years he traveled around the world cataloging all organisms he saw
