Chapter 5 (module 14 + 15) Flashcards
How many species has scientists approximately named?
2 million species
What is the majority of the species named?
insects
The number of species in a given area
Species richness
The relative proportion of individuals within the different species in a given area
Species evenness
How does it help scientists by knowing the species richness or evenness?
It helps because it gives them a baseline they can use to determine how much an ecosystem has changed.
What are 2 different measure of species diversity?
species richness and evenness
The branching pattern of evolutionary relationships.
Phylogeny
What are phylogenies based on?
The similarity of traits among species.
Indicates how different groups of organisms are related and show where speciation events occur.
Phylogenetic tree
A change in the genetic composition
evolution
evolution below the species level, a change in gene frequency in a population.
micro evolution
evolution that gives rise to new species, genera, family, classes or phyla
macro evolution
A physical location on the chromosomes within each cell of an organism
gene
The complete set of genes in an individual
Genotype
A set of traits expressed by an individual
Phenotype
A random change in the genetic code produced by a mistake in the copying process.
mutation
a genetic disorder that creates moon cells
sickle cell anemia
people with sickle cell have some genetic protection against _____
malaria
The genetic process by which one chromosome breaks off and attaches to another chromosome during reproductive cell division
Recombination
What allows new allele combinations to come together, which provides new immune defenses.
Recombination
Process that doesn’t create new genes, but brings together new combinations of alleles on a chromosome, producing new traits.
Recombination
The process in which humans determine which individuals breed, typically with a preconceived set of traits in mind.
evolution through artificial selection
unintended result of artificial selection
herbicide resistance
the process in which the environment determines which individuals survive and reproduce
evolution by natural selection
All species produce an excess amount of offspring and only the fittest genotypes will pass on their genes on the next generation
natural selection
An individuals ability to survive and reproduce
fitness
a trait that improves an individuals fitness
Adaptation
As the number of mutations accumulates in a population over time, evolution occur
evolution by mutation
the process by which individuals move from one population to another and thereby alter the genetic composition of both populations
gene flow
A change in the genetic composition of a population over time as a result of random mating
Genetic drift
evolution that can occur through random process
Mutation, gene flow, gene drift, bottleneck effect, and founders effect
a reduction in the genetic diversity of a population caused by a reduction in its size
bottleneck effect
the death of the last member of a population
extinction
a change in the genetic composition of a population as a result of descending from a small number of colonizing individuals
founder effect
what problems can low genetic variation in a population cause?
increased risk of disease and low fertility
what role is genetic drift particularly useful in?
altering the genetic composition in a small population
