Module 1: Processes of Change

evolution

inherited change in a group of organisms over time

no

can evolution occur in an individual?

population

all the individuals of a species that live and reproduce together

species

a group of individual organisms that can mate together and create fertile offspring

allele

different versions of a gene/genetic element that leads to different phenotypes

gene

the parts of DNA that specify a trait; new traits occurs via mutations or crossbreeding

evolutionary processes

what did biodiversity arise from?

1500

from how many species did Darwin collect specimens from?

south america

where did Darwin collect his speciemens from?

fossils, changes in the Earth, species on the mainlands vs.islands, and differences in neighboring and island species

what were Darwins main 4 discoveries?

similarities and differences between living organisms and fossils of extinct ones

what did Darwin notice in terms of fossils?

Earthquake, petrified wood, and coral reefs rising from deep in the ocean

what are some of the changes in the Earth we discussed in class?

Darwin’s finches and tortoises and shell shape

what are some examples of the difference in neighboring and island species that Darwin observed?

adaptive radiation

when a population encounters many open ecological niches, so it diversifies to fill the available ecological roles

resource limitation

what determines the number of offspring?

descent with modification

the gradual diversification of species, potentially into new species, through the mechanisms of natural selection

no

does evolution deal with the origin of species?

observations of descent with modification, geological evidence, transitional fossils, intermediate forms, and experimental evidence

what are the 5 main types of evidence we have for evolution?

species are not fixed and closely related species can have different adaptations for different niches

what do observations of descent with modification tell us about species?

measure geological processes to date evolutionary events

how can we use geological processes to get geological evidence for evolution?

transitional fossils

any fossilized remain of a life form that shares common traits with an ancestral group and its descended group; indicates gradual change in the fossil record

intermediate forms

gradual shapes between simple and complex structures; ex: the eyeball

researchers began with bacteria and placed it into a media with a bead; they then grew the bacteria and put the bead into new media to allow the bacteria that evolved to attach onto the bead surface would survive

explain the experiment we discussed in class as an example of experimental evidence for evolution

natural selection or genetic drift

through which two mechanisms can evolution occur?

resources are limited

why is exponential growth uncommon in a population?

individuals vary, some variation is heritable, there is a struggle for existence, and individuals with favorable variations survive and reproduce

what are Darwin’s 4 postulates?

heritability

the proportion of phenotypic variation that is due to genetic variation

no heritability

what does h²=0 mean?

some heritability

what does h²=0.5 mean?

strong heritability

what does h²=1 mean?

protein coding changes or expression changes

what could have caused the changes to the beaks of Darwin’s finches, relative to heritable variation?

artificial selection, homologous structures, development, common genetic code, and biogeography

where is descent with modification apparent?