Evolution Flashcards
Catastrophism
Earth’s features developed suddenly to due violent and short lived events
Uniformitarianism
Dis by HUtton and Lyle. Whatever formed the earth in the past are ongoing
Theory of evolution
Characteristics of species change from generation to generations
Natural Selection
What organism is best for survival out of all organisms for a specific environment
Key Idea 1: Variation within species
- Members within a species vary one another in important ways.
- Example: Height of giraffe, thickness of fin…
Key Idea 2: The struggle for existence
High birth rates and shortage of life’s basic resources causes competition among and within species.
Key Idea 3: The inheritance of traits
Characteristics exhibited by one parent are passed down to the next generation
Survival of the fittest
The ability of an organism to survive and reproduce in its specific environment is fitness
Adaption
Characteristics that improve the chance of survival (inherited characteristics)
Fitness
the ability of an organism to survive and reproduce in its specific environment
Descent with modification
All species have descended with changes over time from other species
Variation
Different combinations of alleles that create variation
Mutation
a permanent change in genetic material of an organism and is the only source of new genetic variation (Happens during crossing over)
Selective advantage
a genetic advantage that improves an organisms’ chances of survival, usually in a changing environment
Adaptation
a process that helps a living thing survive and produce in a certain environment
Structural Adaptation
physical features that help with survival
Behavioral Adaptation
things organism do to survive
examples: bird calls, migration, raising offspring, herd behaviour
Physiological Adaptation
changes or chemical reactions that occur within an organism
(things that happen in the inside)
- Example: hibernation, being poisonous or venomous bite are some examples
Development
Environmental conditions: Determines if variation is positive negative or neutral
Positive: survival & reproductive success
Negative: Challenges that limit survival
Neutral: Nothing happens
Evidence from the Fossil Record
Found in sedimentary rocks which shows the remaining of past life (bones)
Fossil Record: every fossil found on earth
Fossils in young layers are more closer to modern animals
Evidence from Anatomy
The study of anatomy provides evidence of evolution, as similarities in body structure point to a common ancestor
Homologous Structures
structures are similar in structure but different in function
Analogous Structures
structures are similar in function but differ in structure (does not show common ancestry)
Vestigial Structures
remnants of organs or structures that had a function in an early ancestor, but no longer serve a purpose
Evidence from Embryology
The study of early, pre-birth stages of an organism’s development
Similarities in the embryos of fish, birds, and mammals provide evidence of evolution of species from a common ancestor
Evidence from Biogeography
The study of past and present geographical distribution of organisms
- Areas that are geographically close are populated by related species
- Animals found on islands often closely resemble animals found on the closest continent
- Fossils of same species found on coastlines of neighbouring continents
Evidence from DNA
Closely related organisms will have similar DNA, RNA and protein sequences.
Species Extinction
- George Cuvier
- Species can and gone extinct (found as fossils)
Acquired characteristics
- Jean Baptiste Lamarck
Creatures adapt to their environments by altering their bodies for offspring
The struggle for existence
There will be self-restraint or external factors which limit the population
Selective pressure
environmental factors/changes that are not good for organisms
Camouflage
species blend to environment
Mimicry
mimics other organisms in order to survive
