Evolution Flashcards
What is Evolution?
- is the process of biological change over time
What are variations? (Evolution)
- structural, functional, or physiological differences between individuals
What are structural adaptations? (Evolution)
- physical features an organism has
What are functional adaptions? (Evolution)
- special biological processes that an organisms body might perform to be well suited to its environment
(Ex: when we get hot, we sweat so that when it evaporates, we cool down)
What are physiological adaptations? (Evolution)
- an internal change that animals / plants go through to ensure their survival in their environment
What are some sources of genetic variation? (Evolution)
- through DNA mutations
- provide new alleles
- if the mutation changes the DNA in a gamete, it be passed on to the future generations
What are adaptations? (Evolution)
- structure, behaviour, or physiological process that helps an organism survive and reproduce in a particular environment
(Mimicry is a type of structural adaptation)
What are examples of structural adaption? (Evolution)
- polar bears
- hummingbirds
- camels
What is an example of a behavioural adaption? (Evolution)
- hibernating during the winter
What are examples of physiological adaptations? (Evolution)
- temperature regulation
- release of toxins or poisons
What is selective advantage? (Girafe example) (Evolution)
- genetic advantage that improves an organisms chance of survival
Ex: because giraffes have long necks, it will be easier for them to survive if the leaves are high up as they can reach and adapt to that
What is natural selection? (Evolution)
- a mechanism of evolution in which living organisms adapt and change
- nature selects!
Who developed natural selection? (Evolution)
- Charles Darwin
What is fitness? (High fitness) (Low fitness) (Evolution)
- the ability to survive and reproduce, advantageous alleles to the offspring
- high fitness: organism can survive and reproduce to make offspring that can then survive and reproduce
- Low fitness: organism cannot survive or has few or no viable offspring
Why does natural selection occur? (Evolution)
- selective pressure: an abiotic or biotic environmental condition that selects FOR or AGAINST a certain characteristic
What is the difference between natural selection and artificial selection? (Evolution)
natural selection:
- nature selects!
- variation in population
- traits must be heritable
artificial selection:
- humans selects!
- variation in population
- traits must be heritable
What are the consequences of artificial selection? (Example with the bulldog) Evolution)
- often decreases genetic diversity - makes the population less fit
- increased risk of genetic diseases (mutations)
Ex: English bulldogs suffer from respiratory problems as they have flat faces
What is selection? (Evolution)
- process where traits are selected FOR or AGAINST and becomes MORE or LESS abundant
How does natural selection occur? (Evolution)
- genetic mutations that are beneficial to an individual’s survival are passed on through reproduction
What is selective pressure? (Example with the tree and the moths) (Evolution)
- the thing that causes the other thing to adapt!!
Ex: dark tree and dark moth. Dark moth blends in as the white moth stands out. Dark tree is the selective pressure as the dark moth has to adapt to survive.
What was Charles Darwin’s contribution to the theory of evolution? (Evolution)
- he believed organisms to change over time
- new species come from pre - existing species
- all species share a common ancestor
What is the definition of fossil evidence? (Evolution)
- any ancient remains, impressions, or traces of past life
What is the importance of chronological order? (Evolution)
- to show the movement of time or steps in a process
- from beginning to end
What are transitional fossils and organisms? (Evolution)
- shows the link between past and present groups of organisms
What are vestigial structures? (Evolution)
- structures that have no apparent function and appear to be residual parts from a past ancestor
What are examples of vestigial structures found in humans? (Evolution)
- wisdom teeth
- tailbone
- appendix
- tonsils
- pinky toes
What is the definition of homologous vs. analogous structures? (Evolution)
Homologous: similar origin BUT different function
Analogous: similar function BUT different origin
What is the definition of biogeography and its importance? (Evolution)
Definition: the study of the distribution of plants, animals, etc. (Location)
Importance: provides information about how and when species may have evolved.
What is the definition of embryology and its importance? (Evolution)
Definition: the study of early forms of life before birth. (pre - birth)
Importance: important to understanding a species’ evolution
What is the importance of DNA / molecular evidence? (Evolution)
- species with similar DNA shared a common ancestor
What is gene pool vs. allele frequency? (Evolution)
Gene pool: complete set of all alleles contained within a species or population
Allele frequency: how common an allele is within a population
What are the 5 factors of microevolution? (Just name!) (Evolution)
- Mutations
- Gene Flow (migration)
- Non-random mating
- Genetic drift
- Natural selection
What are mutations? (Effect) (Evolution)
- mutations are random changes in genetic information, introducing new alleles
Effect: mutations in gametes can be passed on and can affect evolution
What is gene flow? (Effect) (Evolution)
- gene flow (migration) is the net movement of alleles from one population to another as a result of the migration of individuals
Effect: increase the genetic variation of the population
What is non-random mating? (Example) (Evolution)
- mating among individuals on the basis of selection for particular phenotype or due to inbreeding
Example: male caribous will use their antlers to fight each other and compare for mates. The male with the stronger antlers (favourable phenotype) will be able to meet with a female
What is genetic drift? (Founder effect vs. Bottleneck effect) (Evolution)
Founder effect: when a small group of individuals leaves a population to create a new isolated population (occurs on islands)
Bottleneck effect: when the gene pool rapidly changes due to a rapid decrease in population size (can be caused by starvation, disease, natural disasters)
What is natural selection? (stabilizing, directional, disruptive, sexual) ~graphs~ (Evolution)
Stabilizing: selection favours the intermediate (most common) phenotype
Directional: favours the phenotypes at one extreme over the other
Disruptive: when extreme phenotypes are favoured over the intermediate phenotypes
Sexual: natural selection based on mating, competition between males and choices made by females
Species vs. Hybrid: (examples) (Evolution)
Species: is population that can produce viable fertile offspring
Hybrid: offspring of two different species. Often sterile or will produce sterile offspring.
Ex: mule, liger, zonkey
What is speciation? (Allopatric vs. Sympatric) (Evolution)
Allopatric: when a species separates into 2 separate groups that are isolated from one another
Sympatric: the splitting of an ancestral species into 2 (or more) reproductively isolated groups without geographical isolation of those groups
What are the 2 reproductive isolating mechanisms? (Evolution)
- Pre-zygotic
- Post-zygotic
What are the pre-zygotic isolating mechanisms? (Explain) (Evolution)
- Behavioural: differences in behaviours prevent individuals from breeding
- Habitat: two species live in the same general area, but in different habitats
- Temporal: timing barriers prevent mating (different time,season, or year for mating)
- Mechanical: anatomical differences between mates prevent mating
- Gametic: sperm and egg do not meet to form a gamete
What are the post-zygotic isolating mechanisms? (Explain) (Evolution)
- Hybrid inviability: prevents development of the zygote
- Hybrid sterility: hybrid zygote develops, but is sterile
- Hybrid breakdown: first generation of hybrids is viable and fertile, but the next generation is either sterile or weak
What’s the study of the pre-birth stage of life? (Evolution)
- embryology
What is the definition of micro evolution and macro evolution (Evolution)
- Microevolution: the process by which organisms change in small ways over time
- Macroevolution: refers to larger changes that result in new species
What is the definition of pre-zygotic and post-zygotic? (Evolution)
Pre-zygotic: pre-fertilization barrier
Post-zygotic: egg is fertile but zygote does not develop into viable, fertile individuals
What was Darwin’s theory of Natural Selection? (Just name!) (Evolution)
- Overproduction
- Variation
- Selection
- Adaptation
