Evolution Flashcards
Adaptation
A structure, behaviour, or physiological process that helps an organism survive and reproduce in a particular environment.
Variation
Differences between individuals, which may be structural, functional, or physiological.
What determines whether a variation is positive or negative for the individual organism?
Interaction with the environment
Describe mimicry
A type of structural adaptation. Harmless species physically resemble a Harmless species. Predators avoid the harmless species as much as they do the harmful ones
What is selective advantages?
It is a genetic advantage that improves an organisms chances of survival in terms of both survival in a changing environment and reproduction.
Where does selective advantages arise from?
Arises from a mutation that has became beneficial, even if it was a disadvantage at first.
Natural selection
The characteristics of a population of organisms change over time. This occurs because individuals survive and pass their genetic information on to their offspring.
Selective pressure
Environmental conditions that select for certain traits of individuals and select against other traits.
Key points about natural selection
-no purpose -no direction -doesn’t produce “better” individuals -it’s situational -wheat her or not a trait is favoured depends on the environment at that time.
Fitness
How well an individual can pass on their genetic information to offspring that will survive long enough to reproduce.
Artificial selection
Selective pressure exerted by humans to produce desirable traits in populations.
Biotechnology
The use of technology to control and determine the traits in organisms.
Charles Darwin
-natural selection -survival of the fittest -the preservation of favoured races in the struggle of life
James ussher
October 23 4004 B.C
George Buffon
Living things change through time
Mary anning
Discovered fossils of a plesiosaur, one of the first aquatic reptiles discovered.
George Cuvier
Catastrophism (violent events have changed the earth)
Charles Lyell
Cuviers catastrophism theory is wrong. Slowly progresses over time. Earth very old, the same natural process for shaping the land occurs today as it did year ago. Creates uniformitarism with Hutton
James Hutton
Uniformitarism, current geological processes occur at the same rates today as they did in the past. “The presents the key to the past”
Erasmus Darwin
Suggested evolution of life
Jean baptiste Lamarck
Acquired traits
Fossils
Evidence for the history of life
Fossils
Evidence for the history of life.
Transitional fossils
Represent links between one organism to another.
Vestigial features
Limbs that still excise from when an animal transitioned from land to water or opposite.
Biogeography
Study of past and present geographical distribution of species population
What is the evidence of evolution we have?
Fossil record, biogeography, from anatomy, from DNA.
Homologous structures
Structures that have the same physical parts but may have different analogous structures.
Analogous structures
Structures that preform common tasks but don’t share an evolutionary ancestor.
What are the factors affecting change of allele frequency?
Mutations, gene flow, non-random mating, genetic drift, natural selection
Mutations
Random changes in the sequence of DNA through unrepaired changes, chromosome breakage and rejoining.
Gene flow (migration)
The movement of alleles from one population to another through the movement of individuals or gametes.
Non random mating
This occurs when mates are selected over others
Inbreeding
Part of non random mating. Self fertilization (plants) or mating with closely related individuals. (This can create negative effects, increases homozygous genotypes).
Genetic drift
Changes the allele frequency as a result of chance.
The founder effect
Part of genetic drift. New populations formed by a few individuals leaving the old population (founders).
Bottle neck
A dramatic, temporary, reductionism population size resulting in significant genetic drift.
What are the four types of natural selection?
Stabilizing selection, direct selection,disruptive selection, sexual selection.
Species
Consists of members of interbreeding groups or populations that are reproductively isolated from other groups and evolve independently.
Reproductive isolating mechanisms
Any behavioural, structural, or biochemical trait that prevents individuals of different species from reproducing successfully together.
What are some behavioural isolation for reproductive isolating mechanisms that prevent mating?
Habitat isolation, temporal isolation, and behavioural isolation.
What are mechanical isolations that prevent fertilization?
Mechanical isolation and game tic isolation
What are the modes of speciation?
Allopatric Speciation, and Sympatric Speciation
Allopatric speciation
The creation of new species due to a physical barrier.
How can new species be created from the allopatric speciation?
Populations at the periphery or edge of the population can split off. Natural selection can also create new species when they are separated if the environment is different from the old.
Sympatric speciation
Populations can split into two separate gene pools and remain in the same geographic area.
How can Sympatric speciation occur?
Due to chromosomal changes (plants) and non-random mating (animals) that alter gene flow.
What is an example of how Sympatric speciation can happen?
Dolyploidy in plants (have one or more diploid number) can create plants with 3 sets of chromosomes. This can create gametes with the diploid #. If two diploid gametes fuse, they will create a tetraploid individual. This can create 2 seperate species.
Divergent evolution
The process by which a species evolve into 2 or more descendent or different forms.
Convergent evolution
The appearance of apparently similar structures in organisms of different lines of descent.
