Biology Unit 3: Evolution
What is a scientific theory?
An explanation for a body of evidence
What are changes that occur to organisms over a period of time called?
Adaptations
What are mutations?
A method of causing change within an organism
What helps lead to variation within a species?
Mutations
True/False: Mutations can only be harmful.
False. Mutations can be harmful, neutral, or beneficial
What is artificial selection?
Parents are chosen so the offspring will have particular traits
What is another name for artificial selection?
Selective breeding
Who was the key contributor to the idea of evolution?
Lamarck
What were Lamarck's major suggestions?
All species evolve overtime, species evolve and become better adapted in response to their environment, and changes are passed from generation to generation.
What is the study of fossils?
Paleontology
What did Georges Curvier note from his study if fossils?
Simple fossils are found much deeper than complex fossils
Who proposed the idea of catastrophism?
Cuvier
What is catastrophism?
The suggestion that fossil patterns could be explained by a series of catastrophes that wiped out most species on earth
Who suggested uniformitarianism?
Charles Lyell
What is uniformitarianism?
The suggestion that earth has been changing slowly and gradually and is very old
What is biogeography?
The geographic distribution of organisms based on loving species and fossils
What are homologous features?
Features that have common evolutionary origin but serve different functions
What are analogous features?
Structures that have similar function but different origin
What are structures that no longer serve a purpose called?
Vestigial features
Why might there be competition within large populations of a species?
Limited availability of food
What is natural selection?
The way in which nature favours the reproductive success of some individuals over others
What are the four different types of natural selection?
Directional, stabilizing, disruptive, and sexual
What type of natural selection favours more extreme variations of a trait?
Directional selection
What type of natural selection favoura the average variation of a trait?
Stabilizing selection
What is the type of natural selection that favours two or more variations of a trait?
Disruptive selection
What type of natural selection favours a trait or behaviour during the selection of mates?
Sexual selection
What is a result of evolutionary change without selection?
Reduced genetic diversity within a population
What is genetic drift?
The random change of allele frequency in a small population
What is the bottleneck effect?
When a large population is suddenly and drastically reduced in size
What is the founder effect?
When a small number of individuals separate from a larger population to form a new population
What is genetic equilibrium?
A population whose genetic and fenotype frequencies do not change from generation to generation
What is the Hardy-Weinberg Principle?
The idea that in large populations, in which only random chance is at work, allele frequenct will stay the same
What is the equation for allele frequency?
p+q = 1
What is the equation for genotype frequency?
p^2 + 2pq + q^2 = 1
Any factor that causes allele frequency to change leads to what?
Evolutionary chnage
What 5 conditions result in evolutionary change?
Natural selection, small population, mutation, immigration/emmigration, and horizontal gene transfer
What is a horizontal gene transfer?
Gaining new alleles from different species
What is microevolution?
The small changes that occur within a species
What 3 things determine a species?
Similar characteristics, interbreeding hnder natural causes, and their offspring are fertile
What are biological factors that prevent interbreeding called?
Reproductive isolating mechanisms
What are the two different catagories of isolating mechanisms?
Prezygotic and postzygotic
What type of isolation can be described as different courtship to find a mate?
Behavioural isolation
What type of isolation can be described as different breeding times?
Temporal isolation
What type of isolation can be described as different habitats?
Ecological isolation
What type of isolation can be described as different morpholgical features?
Mechanical isolation
What type of isolation can be described as unrecognizable gametes?
Gametic isolation
What type of isolation can be described as a zygote that can not develop properly?
Zygotic mortality
What type of isolation can be described as a organism that dies before birth or does not make it to maturity?
Hybrid inviability
What type of isolation can be described as healthy offspring that are unable to reproduce?
Hybrid infertility
What is allopatric speciation?
The formation of a new soecies due to changes following a period if geographic isolation
What is sypatric speciation?
The formation of a new species within an existing population die to disruptive selection
What type of speciation can also result from polyploidy?
Sympatric speciation
What is adaptive radiation?
The rapid evolution of a single species into many
What is divergent evolution?
The large scale evolution of a group into many different forms
What is convergent evolution?
The formation of similar traits in distantly related species
What is coevolution?
When one species evolves in response to another species evolving
What is macroevolution?
The large scale evolutionary changed that result in species formation
What is abiogenesis?
The origin of life from non-living matter
What is cladistics?
A method of mapping evolutionary relationships based on recently evolved traits
What is gradualism?
The theory that suggests evolution is slow and gradual
Who suggedted the ideo of punctuated equilibrium?
Niles Eldridge and Steven Jay Gould
What did pucturated equilibrium suggest?
New species evolve rapidly in evolutionary time, speciation occurs in small isolated populations, and after the initial bursts of evolution, additional changes are very slow