Unit 10 vocabulary Flashcards
determining the relative ages of fossils without actually determining their precise age; in other words, knowing that one fossil is older than other because it is located deeper in the rock layers
relative dating
using the known decay rate of certain isotopes (like carbon 14) to determine the age of rocks and thus the age of the fossils contained within the rock
radiometric dating
the time required for half of a sample of isotope to decay
half life
theory that explains how the large blocks of earths crust move around
plate tectonics
a system of measurement to describe the history of earth
geologic time scale
the oldest era; made up of simple, single celled organisms; 4.6bya-540 mya
precambrian
the era after the precambrian; 540 mya- 245 mya; begins with an explosive radiation of new life forms and ends with a mass extinction event that coincides with the formation of the supercontinent pangea
paleozoic
the era after the paleozoic; 245mya- 65mya; begins with an explosive radiation of new life forms (particularly reptiles) and ends with the mass extinction of the dinosaurs that coincides with a meteor impact
Mesozoic
the most recent era; 65mya- present;begins with an explosive radiation of new life forms (particularly birds and mammals) and is still going
Cenozoic
an event in the fossil record in which a large majority of the species present go extinct and are not seen in the fossil record again
mass extinction
an event in the fossil record in which a large number of new species or forms appears in the fossil record in a very short period of time
explosive radiation/ adaptive radiation
stands for billion years ago
BYA
stands for million years ago
MYA
the large continent formed at the end of the paleozoic that is made up of all of the modern continents
Pangea
change in populations over time
evolution
a well supported idea in science that explains all observations from a phenomenon; all observations, experiments, etc. support the theory; no evidence disputes the functioning of the theory
theory
wrote “On the Origin of Species by Means of Natural Selection” after taking a 5 year voyage around the world on the HMS beagle and visiting the Galapagos Islands
Charles Darwin
also developed the idea of natural selection by means of natural selectjon at the same time as Darwin
Alfred Russel Wallace
selecting desired traits for the purpose of breeding animals like dogs, cats, cattle, etc.; what caused the evolution of all the different kinds of dog breeds
Artificial selection
when organisms with a desirable variation survive, reproduce, and pass on that favorable variation to future generations
natural selection
the ability to survive, reproduce and pass on traitd to future generations
fitness
another way of thinking of natural selection
survival of the fittest
where Darwin visited and observed so many organisms that helped to shape his ideas about natural selection
Galapagos Islands
more babies are born than can survive in a population
Overproduction
all individuals in a population are genetically different (due to presence od mutations that accumalate variety in a species)
variation
any factor that results in natural selection (like a drought, a predator, competition for food, etc.)
selection pressure
those individuals that are best adapted are most fit
best adapted
over a long time
many generations
any variatjon that improves the chances of an organism surviving, reproducing, and passing on its traitd to future generations
Adaptation
an example of an adpatation in which species can blend in to their surroundings
camouflage
an example of an adaptation in which species can copy the appearance of more dangerous organisms
mimicry
a classic example of observed, documented, natural selection in action; peppered moths evolved in response to large scale enviromental changes observed in and around london after the beginning of the industrial revolution
peppered moth
another classic example of observed, documented, natural selection in action; bacteria evolve resistance to antibiotics (meaning the antibiotic no longer works and kills the bacteria) as a result of the strong selection pressure applied by treating so many bacterial infections with antibiotics
antibiotic resistant bacteria
same basic structure seen in different organisms due to their evolution from a common ancestor; all terrestrial vertebrates have the basic bone structures in their limbs
homologous structure
a structure present in a modern organism that has no mnown function but it is present because it was useful in an ancestral species; like humans having gill slits during their embryo develop
vestigial structure
a similar structure seen in different organisms due to their experienceing similar natural selection pressures (not evolved from a common ancestor); like birds and insects having wings
Analogous structure
the basic limb structure of all terrestrial vertebrates ( the same 5 digit plan)
pentadactyl limb
a single species from which multiple modern species evolve
common ancestor
the studying of embryos to understand evolutionary relationships
embyrology
the studying of DNA to understand evolutionary relationships
Biochemical evidence
a group of individuals of the same species living in the same place at the same time
population
all of the genes of a population
gene pool
how common a particular allele is in a population
allele frequency
when allele frequencies do not change in a population over time
genetic equilbrium
a permanent change in DNA; alters allele frequencies of a population by introducing new alleles to a population
mutation
a change in allele frequencies of a population due to chance events
genetic drift
a change in allele frequencies in a population due to some males reproducing more than others due to female preferences
sexual/ mate selection
resukts in a change in allele frequencies by the movement of individuals from one population to another
migration
when organisms with a desirable variation survive, reproduce, and pass on that favorable variation to future generations
natural selection
a type of genetic drift event in which a population’s allele frequencies are changed due to the settling of a new population by just a few individuals
founder effect
a type of genetic drift event in which a population’s allele frequencies are changed due to a population being reduced dramatically to just a few individuals
bottleneck
permanent and complete removal of a species from environment
extinction
the movement of genes from one population to another that results when individuals migrate
gene flow
movement of genes into a population
immigration
movement of genes out of a population
emigration
a group of individuals that can breed to produce fertile offpspring (offpspring can grow up and have babies)
species
the evolution of new species
speciation
any barrier that prevents two individuals from being able to meet up and breed (like being seperated from one another by a river, valley, canyon, etc.)
prezygotic barrier
a type of pre-zygotic barrier in which individuals are physically seperated from one another
geographic isolation
speciation that results from geographic isolation
allopatric speciation
species that results without geoegraphic isolation
sympatric speciation
any barrier that prevents two individuals from being able to create fertile offspring (like they are too genetically different and the egg can thus not be fertilized by the sperm)
postzygotic barrier
a type of post zygotic barrier in which individuals are physically unable to form fertile offspring, even if they try to mate
reproductive isolation
a speciation event that occurs in plants
polyploidy
evidence of an organism from the past; must be at least 10,000 years old
fossil
