Evolution Flashcards
Why women keep getting prettier (info)?
Hormones can have a very large effect on women and their pregnancies and relationships. Their BMI index, weight is a big component that women have to care for in order to be the apparent “beautiful standard” to men. Cultures and many different people find beauty standards different.
Where did the word evolution come from?
Evolutio- ‘to unroll’
It has early embryological meaning.
What is the historical perspective of evolution?
Pre Darwin: Development of an individual from preformed representation in the embryo to the final organism.
Darwin’s Time: Progressive development of life from simple to complex.
Post Darwin: Genetically based on heritable change in one or more characteristics in a population or species through time.
What is evolution NOT?
- Progress
- Goal determined change
- Pre-determined
Who is Francesco Redi?
He conducted an experiment using maggots and meat
Who is Lazzaro Spallanzani?
He wanted to disprove spontaneous generation and set up the flask experiment
Who is Louis Pasteur?
Similar experiment to Spallanzani but he allowed air flow into both flasks
Who is Carl Linnaeus?
He was the founder of modern classification and systematics
Who is Georges-Louis Leclerc Comte de Buffon?
He looked after royal gardens in France. Formulated a species concept based on interbreeding
Who is Jean-Baptiste Lamarck?
He was a firm believer in the fixity of species. Network idea instead of the normal chain idea. Spontaneous generation experiment.
Who is Charles Lyell?
Very religious geologist. Assumed consistency of natural laws (except in the origin of species, too vague).
Who is Charles Darwin?
Was born in England. At 16 he studied medicine and at 18 he went to become a minister. He was an unpaid naturalist on the Beagle.
What was Darwin’s experience on the Beagle like?
Was on it for 5 years. Spent most of his time investigating the geology and life of the islands. Observed plants and animals.
What are Darwin’s finches?
He studied the finches on the mainland vs the Galapagos island. Finches adapted to the island and could eat things like seeds, worms, fruit and leaves.
Who is Thomas Malthus?
Malthus was widely believed to have demonstrated that population growth would outstrip the food production unless population growth was put in check.
Who is Alfred Wallace?
He was the main competitor! Him and Darwin has similar theories and were planned to publish a similar time. Darwin knew Wallace had more credibility than he did so he wanted his paper published alongside Wallace’s.
What points did Darwin make in the origin of species?
- All species of living organisms on Earth today are descended from ancestral species
- The mechanism that causes species to change over time is natural selection
What is decent with modification?
When species moved around many many years ago and had to adapt to the land and environment around them.
What is natural selection?
Natural selection is a process where:
- heritable traits allow and organism to survive
- organisms can successfully reproduce
- traits become more common within the regular population
What does natural selection require?
- Reproduction
- Heredity
- Variation in population
- Fitness differences associated with variation in population
What is fitness?
Probability to survive and reproduce. Average number offspring produced by a single genotype relative to number offspring produced by another genotype. Fitness is the relative reproduction success as measured by selection in a particular environment.
What is macroevolution?
- Large amounts of change
- Give rise to new species
- Difficult to design experiments to test for this
- Time scale is one of the biggest problems
What is microevolution?
- Changes in gene or allele frequency
- Changes within a species, between populations
What is speciation?
The origin of a new species
What is extinction?
The disappearance of a species
What are the three speciation types?
Allopatric – different homelands with no gene flow between them
Parapatric – side by side homelands
Sympatric – same homelands
What is allopatric speciation?
- Major type of speciation in vertebrates
- Geographic isolation
- The bigger the barrier the more extreme the segregation
What is parapatric speciation?
- Adjacent population with a hybrid zone
- Heavy metal tolerance in grasses
What is sympatric speciation?
- Within the same population area
- May not be important in motile animals
- Evolution of wheat
What info do we know about arthropods?
- Throughout their history, arthropods have invaded new geographic areas and habitats
- Successfully invaded new ecological niches
- Around for more than 500 million years and are still evolving
What is the evidence of evolution?
- Geographic distribution
- The fossil record
- Comparative anatomy
- Comparative development
- Molecular biology
- Artificial selection
- Antibiotic resistance in bacteria
What is the fossil record?
Demonstrates evolutionary changes do occur. Almost all fossils are in sedimentary rock. The disadvantage of the fossil record is that it is generally difficult to determine the selective forces that may have contributed to these changes
The advantage of the fossil record over present day observations of evolution is that higher order evolutionary changes may be tracked
What is artificial selection?
Occurs when humans selectively breed organisms for their own benefits. Examples includes horse breeder, cat breeder and dog breeder.
What is heritability?
One of the most important qualitative genetic properties. Predicts the response to selection and expresses the reliability of the phenotype in determining the breeding value.
What are the three types of artificial selection?
- directional selection
- stabilizing selection
- disruptive
What is genetic drift?
A chance event can cause a change in allele frequency
