Unit 1: Evolution (ch.16,17,18) Flashcards
The study of patterns in the geographic distribution of species and communities is known as what?
Biogeography
The scientific study of similarities and differences in body plans of organisms.
Comparative Morphology
who was the scientist that developed the Theory of Catastrophism?
Georges Cuvier
Who was the scientist that stated environmental pressure caused changes in the needs of organisms living in that environment which in turn changed their behavior?
Jean-Baptiste Lamarck
What scientist proposed that gradual everyday geological processes (such as erosion) shaped the Earth’s surface?
Charles Lyell
What is Uniformitarianism?
the idea that gradual repetitive changes over time shaped the Earth
what is fitness?
Degree of adaptation to an environment
what are different forms of a gene?
alleles
What requires the measuring of radioisotope and daughter element content?
Radiometric dating
Who is the scientist that co-discovered the process of evolution with Charles Darwin?
Alfred Wallace
where do you find the oldest fossils in sedimentary rock?
the deepest layers in the formation are the oldest
What is a population?
All the organisms of the same species or group that live in a specific area and are capable of breeding among themselves
What is a gene pool?
all alleles of all genes in a population; a pool of genetic resources
What is microevolution?
Allele frequency that changes over time
What is genetic equilibrium?
It is the theoretical state in which an allele’s frequency never changes and maintains a stable state so long as the 5 conditions are met.
What is the primary formula for Hardy-Weinberg formula?
p^2+2pq+q^2=1.0
What is Directional Selection?
a form of a trait at one end of a range of variation is adaptive.
What is Stabilizing selection?
an intermediate form of a trait is adaptive, and extreme forms are selected against.
What is Disruptive Selection?
forms of a trait at both ends of a range of variation are favored, and intermediate forms are selected against.
What are the three modes (types) of natural selection?
Directional, Stabilizing, and Disruptive
What are the three types of Speciation?
Allopatric, sympatric, and parapatric
What is allopatric speciation?
A physical barrier interrupts gene flow between populations
What is Sympatric Speciation?
Genetic changes lead to reproductive isolation within a single population.
What is Parapatric Speciation?
Where populations in contact across a shared border become different species.
what are the names of the main two super continents?
Pangea and Gondwana
the Theory that Earth’s outermost layer of rock is cracked into plates, the slow movement of which conveys continents to new locations over geologic time.
Plate Tectonics theory
how many major extinction events have there been?
5
What are mass extinctions represented by?
Periods
Characteristic time it takes for half of a quantity of a radioisotope to decay.
Half-life
A mutation that has no effect on survival or reproduction
Neutral Mutation
A mutation that alters the phenotype so drastically that it causes death.
Lethal Mutation
abundance of a particular allele among all copies of the gene in a population’s gene pool
allele frequency
What is balanced polymorphism?
Maintenance of two or more alleles of a gene at high frequency in a population.
Individuals of one sex (often males) are more colourful, larger, or more aggressive than individuals of the other sex.
sexual dimorphism
What is genetic drift?
Change in allele frequency due to chance alone
what is genetic flow?
the movement of alleles in to and out of a population.
reduction in population size that is so severe that it reduces genetic diversity.
Bottleneck
What does it mean when an allele becomes fixed?
an allele that all members of the population are homozygous for.
what is the founder effect?
After a small group of individuals found a new population, allele frequencies in the new population differ from those in the original.
The emergence of a new species (as a result of one lineage splitting into two)
speciation
The end of gene flow between populations
reproductive isolation
What is macroevolution?
evolutionary change in taxa above the species level.
The evolutionary history of a species or a group of species
Phylogeny
A quantifiable, heritable trait
character
what is a clade?
A group whose members share a defining derived character
what is a derived character?
a trait shared by all members of a clade but not in any of the clade’s ancestors
a group including an ancestor in which a derived character evolved, together with all of it’s decedents.
monophyletic group
what is cladistics?
making hypotheses about evolutionary relationships among clades.
what are analogous structures?
similar body structures that evolved separately in different lineages (via convergent evolution)
What is convergent evolution?
Morphological convergence. Macroevolutionary pattern in which similar body parts evolve separately in different lineages.
what is divergent evolution?
Morphological divergence. Evolutionary pattern in which a body part of an ancestor changes in its descendants.
What is a molecular clock?
a method of comparing the number of neutral mutations in the genomes of two lineages to estimated how long ago they diverged.
