True or false: All species are temporary
- This is true, extinction is as much a part of nature as is the origin of species
What was Darwin’s definition of evolution?
- Evolution is descent with modification. Populations change over time
What is the current definition of evolution?
- Evolution is a change in allele frequencies in a population over time
What were George Cuvier’s contributions to the study of evolution?
- He was a leading and comparative anatomist and palaeontologist of his time
- Found that many species have gone extinct and that the number of species are declining
- Showed that large bones in USA belonged to extinct msatudon, not modern elephants
What were Charles Lyell’s contributions to the study of evolution?
- Stated that landforms were not fixed, but changed slowly as a result of geological processes that can be observed today (i.e., not caused by biblical catastrophes)
- Earth was much older than the accepted age at the time since the landforms that existed must have formed over more than a few thousand years
What were Jean-Baptiste Lamark’s contributions to the study of evolution?
- Beieved that species changed over time and he called it transmutation
- Lamarckism - acquired traits can be inherited, lost through disuse (epigenetics has somewhat supported this idea)
What were Thomas Malthus’s contributions to the study of evolution?
- Human population can increase faster than food supply, leading to competition and survival of the fittest
- The idea of there being limited resources
- Individuals who can’t compete will be unable to produce offspring
What were the three big ideas that can be taken from Darwin’s “The Origin of Species”?
- The idea that variation in traits such as size, colouration, etc., influence natural selection which leads to differences in fitness among individuals, and those who are able to produce the most offspring pass on their traits through inheritance
- The struggle for existence due to limited resources causes favorable variations to be preserved and passed on to the next generation while unfavorable ones tend to be destroyed
What were Darwin’s 4 postulates?
1) Individuals within a species vary
2) Some variation is inherited
3) More offspring are produced than can survive and reproduce
4) Survival and reproduction is not random, but related to phenotypic variation
True or false: Alfred Wallace copied his ideas from Darwin
- This is false
- Wallace came up with ideas similar to Darwin independantly, but it did spur Darwin to publish his own work on the subject
In Darwin’s ideas, what is the function of natural selection in evolution?
- Natural selection is the main mechanism in biological evolution
- Natural selection could be considered the driving force of biological diversity in different environments
What is the definition of endemic?
- Something that is native and restricted to a certain place
- Ex. The endemic finches of the galapegos islands will share different characteristics between their separate populations
What’s adaptive radiation?
- A process in which organisms diversify rapidly from an ancestral species into many new forms
- Increases biological diversity
True or false: Natural selection without heritability can occur, but evolution by natural selection cannot
- This is true, you cannot have a species evolve without the future generations inheriting the favoured traits
What are vestigial structures?
- Useless body parts that must have functioned in ancestral organisms. Demonstrate that organisms do in fact change.
- Ex. the human appendix
What are homologous structures?
- Organisms that appear similar between different species (i.e., they have homology) because they share a common ancestor
- Ex. the limbs of cats and humans have homology
- May or may not have the same structure but have completely different functions
True or false: Selective breeding in various types of organisms was an idea that developed during the beginning of the 19th century.
- This is false
- Selective breeding in plants and animals has been around for thousands of years
- Selective breeding = artificial selection
True or false: Individuals can evolve within their lifetime
- This is false, individuals cannot evolve within their lifetime
What is the role of mutations in evolution?
- Mutations supply the raw material for natural selection to work with
- While mutations are a source of variation, they do not determine the path of evolution
What’s the definition of generation time?
- The average difference in age between a parent and its offspring
What are analogous structures?
- Physical structures that share similar functions between organisms but aren’t necessarily similar in shape
- Ex. The wings of bats vs. the wings of birds
- They evolve independantly (i.e., not from the same origin)
