Unit 9: Evolution

what are the 3 domains?

Bacteria, Archaea, and Eukarya

phylogeny

Evolutionary history of a species or a group of related species

adaptation

Inherited structures, processes, or behaviors that make organisms of a population better able to survive and reproduce increase in later generations; includes: fitness and natural selection

natural selection

Organisms with the most favorable phenotypes survive better and reproduce more in new environments, thus passing their favorable genes on to future generations

descent with modification

Populations develop different structures and live in different niches or habitats from their ancestors as they adapt to environmental changes

cladogram

Represents a hypothesis using derived characteristics to determine evolutionary relationships

nonrandom mating

Selective mating limits expression of non-favorable alleles, allowing for change over time and adaptation to the environment

fitness

a measure of how much a trait contributes to reproductive success in an environment

divergent evolution

a number of different species diverge (split-off) from a common ancestor (darwin's finches; wolves and domesticated dogs)

hardy-weinburg equilibrium

a population is in genetic/hardy-weinburg equilibrium when there is no change in allele frequency in a species

gene pool

all genes, including different alleles, of all of individuals in a population

Archaea domain's kingdoms

archaebacteria

behavioral speciation

birds don't sing the right song (mating song)

the foundation for biological evolution or descent through modification is...

changes in gene frequency in a population occur from one generation to the next

convergent evolution

different groups of organisms living in similar environments produce species similar in appearance and behavior (worm-like bodies of snakes and legless lizards)

dumb kings play chess on funny glass stairs

domain, kingdom, phylum, class, order, family, genus, species

Bacteria domain's kingdoms

eubacteria

how can fossils best help paleontologists and biologists classify organisms?

fossils allow scientists to have an idea of the time scale that traits evolved

factors that influence genetic variability within a population

genetic drift, gene flow, nonrandom mating, mutations, natural selection

gradualism

gradual changes of a species in a particular way over long periods of time (gradual trend to larger or smaller body sizes)

gradual vs mass extinction

gradual: occurs at a slow rate; mass: catastrophic event changes environment and population can't adapt

vestigial structures

homologous structures with little or no function, remnants of structures that had important functions in ancestors (tailbone, appendix, wisdom teeth)

variation

in inherited traits, affects ability to use resources and reproduce

differences in DNA, proteins, and other molecules tend to ___________ over time

increase

overproduction of offspring

more offspring increases chances some will survive

geographic speciation

mountain ranges, fault lines, etc

gene flow

movement of genes into or out of a population due to a migration of individuals, increasing variability of the receiving population

biological evolution occurs through...

natural selection

macroevolution

on a large scale; affecting changes in species across populations

microevolution

on a small scale; affecting a single population

new species form when...

organisms are isolated/separated so that the new population is prevented from reproducing w/original population

4 principles of natural selection

overproduction of offspring, variation, adaptation, descent with modification

punctuated equilibrium

periods of abrupt changes in a species after long periods of little change within the species over time (sudden change in shape or size)

reproductive speciation

physical, temporal, behavorial

what factor doesn't contribute to natural selection?

population stability

speciation

process of forming a new species through the process of evolution

Eukarya domain's kingdoms

protista, fungi, plantae, animilia

genetic drift

random change in frequency of alleles of a population over time (rare alleles will be eliminated and others will increase/become fixed)

genetic variation is __________ and ensures that each new generation results in...

random; individuals w/unique genotypes and phenotypes, leading to biological evolution

homologous structures

share a common evolutionary history/ancestry but not necessarily the same function (results from divergent evolution)

transitional fossils

show links between organisms; used to document intermediate stages in evolution

the more __________ the DNA and amino acid sequences the more recently a species diverged from a common ancestor

similar

analogous structures

similar in appearance and function due to adaptation to similar environments in different locations NOT common ancestry or evolutionary history (results from convergent evolution)

fossils provide what kind of evidence?

similarities between current/ancient species, a pattern of gradual change from past to present, a history of organisms on Earth, their relative ages, and order of divergence

phenotypic changes are more obvious in ___________ populations than ___________ ones

small; large

what did charles darwin mean when he said some organisms are "more fit" than others?

some organisms are more likely to reproduce

biochemistry

study of chemical processes (genes and proteins) in organisms

paleontology

study of prehistoric structures

While visiting the Galapagos Islands in 1835, Charles Darwin collected over thirteen different species of a type of bird called a finch. He later observed that the birds were similar in many ways but often differed in the size and shape of their beaks. What summarizes Darwin's explanantion for the different beaks he observed in these finch species?

the beaks of each finch species were a result of natural selection

the greater the diversity the greater...

the greater the chance for the species to survive during environmental changes

taxonomy

the science of naming/classifying living things

temporal speiciation

timing of reproductive event is different

physical speciation

two individuals can't mate

coevolution

two or more species living in close proximity change in response to each other - the evolution of one species affects the evolution of the other (lions and zebras; flowers and insects)

5 conditions to maintain genetic equilibrium

very large population (no genetic drift), no movement into/out of population, random mating, no mutations, no natural selection

what information can be determined from phylogenic trees?

what groups are most/least closely related; which group diverged first