Evolution Flashcards
Name of Charles Darwins book that explains his findings about evolution
The Origin of Species
What is evolution?
Descent with modification by natural selection
Species are descendants of an ancestral species different from the one we see today
How is evolution both a pattern and a process?
Pattern: scientific evidence
Process: natural observed changes
Aristotle definition of evolution (384-322 BCE)
life is permanent, unchanging, and perfect
What was Carolus Linnaeus (1707-1778) known for?
He classified life according to their similarities aka based on what they looked like. Linnaean Classification of Taxonomy
Darwin’s theories were influenced by :
Fossils contained within layers of rock called strata
What did Georges Cuvier (1769-1832) observe?
There’s a difference in species between old strata and new strata because of catasyrophic events that lead to extinction
What did James Hutton (1726-1797) propose?
Earth’s geological features = slow process
What did Charles Lyell (1797-1875) propose?
Geological processes of the past are occurring at the same rate in the present
What did Jean-Baptiste de Lamarck (1744-1829) propose?
The first hypothesis for evolution
he suggested that evolutionary change explains the patterns seen in the fossils.
The use/disuse of body parts
Suggested the inheritence of characteristics
Suggested that organisms have a need to be more complex
What was the name of the ship Darwin traveled on?
The HMS Beagle
Name of the islands Darwin studied on?
The galapagos islands
Name of the birds he observed and what intrigued him?
Finches
Their beak shape changed based on their environment and food sources
What is Natural Selection?
Individuals that have certain traits tend to survive better and reproduce due to those traits
What are the three things that Darwin studied? (ECD
- How organisms are suited for their environment
- The shared characteristics of life
- The diversity of life
What is adaptive radiation?
How organisms diversity from an ancestral species into different forms.
Usually occurs after a change in environment that creates new resources
What is artificial selection?
When humans select desired traits to reproduce. ex. dog breeds
The trait must vary and be heritable
Environmental pressure
When the environment forces a change within a species in which they eventually become a separate species
Takes a long time
What are the two observations Darwin made? (IO
- Members of a population vary in their inherited traits.
(allows for natural selection to occur) - Not all offspring will be able to survive and reproduce
(Leads to the favourable traits reproducing)
What is relative fitness?
The contribution an individual makes to the gene pool compared to the rest of the population
Individuals do not evolve…
Populations do
Why can’t natural selection create the perfect organism? (PHC)
- Selection can only act on existing phenotypes
- Evolution is limited by historical constraints
(cannot create new structures, they can only arise through mutation/gene duplication)
- Adaptation are often compromises
(ex. blue footed boobies are good in water but goofy on land)
How is evolution supported by scientific evidence?
- Fossil records
- Vestigal structures
- Homologies
What are Vestigial Structures?
Structures that had a function in past species but are no longer used in a present day species
ex. tailbones and goosebumps in humans and the pelvic girdle in snakes
What homologies do all vertebrate embryos share?
- Post anal tail
- Pharyngeal pouch (gils for fish, ears for humans)
What can be seen in DNA and protein sequences?
Homologies
What is shared by ancestry?
Homologous genes
The more closely the DNA/protein sequence is…
The more closely related species are
What are homologies?
Features that are similar with different functions
