Bio 1 AAC QUIZ 1 evolution

evolution

change in the heritable characteristics of a population over time; process by which modern organisms have descended from ancient organisms

Linnaeus

1700s Swedish Botanist;
created a classification system for organisms grouped by similarities that reflects evolutionary relationships
rejected belief: organisms not changing over time

Buffon

1700s French naturalist
species share ancestors rather than evolve separately (correct)
suggested Earth older: most believed 6000 years old

Erasmus Darwin

1731 doctor and poet, Darwin's grandfather
believed all living things descended from common ancestor
believed more complex forms developed from less complex

Lamarck

1809 French naturalist
believed: environment change leads to behavior change, then use or disuse of a structure and these changes were passed on
idea: use or disuse (wrong)

Cuvier

french zoologist
believed: species could become extinct, fossils in deep layers of rock are different from fossils in upper
proposed: catastrophism

catastrophism

natural disasters shape landforms & cause mass extinctions

Hutton

1700s Scottish geologist
believed: earth older than believed
proposed: gradualism

gradualism

changes in landforms due to slow changes over long period

Lyell

1830s English geologist; wrote Principles of Geology
proposed: theory of uniformitarianism
greatly influenced Darwin

uniformitarianism

prevailing geologic change theory: geological processes are constant and ongoing

Thomas Malthus

1798 British philosopher and economist
believed: If all offspring are able to survive, there won't be enough space or food
on a graph, the population: exponential, increase; food: linear

Alfred Wallace

1858: writes to Charles Darwin about natural selection
1859: Charles Darwin writes "The Origin of the Species" and acknowledges him

Charles Darwin

born 1809 England
most contributed to understanding evolution
traveled world on HMS Beagle as a naturalist seeking a scientific explanation for diversity of life
hypothesis: way life changes over time; led to evolution theory

Darwin's observations

numerous species populate: differences exist within one
each organism suited to their environment
found fossils extinct organisms wondered why they resembled modern animals
variation, or difference in physical traits: some allow survive and reproduce more
"Tree of Life" Idea
wondered if different animals once belonged to the same species

adaptation

inherited feature that allows organisms to better survive in environment; arose over many generations

artificial selection

process by which humans select traits through breeding

natural selection

inherited adaptations: more offspring with existing traits
results: changes in inherited characteristics; increase fitness for survival

principles of evolution

variation, overproduction, adaptation, descent with modification

descent with modification

the idea that species change over time, give rise to new species, and share a common ancestor

adaptive compromise

some structures take on new functions (panda's thumb)

heritability

ability of trait to be passed to offspring

fitness

the measure of survival ability and ability to produce more offspring (survival of the fittest)

differential survival

when some in population have a phenotypic advantage (camouflage)

selective pressure

when changing environments favor some phenotypes over others

fossils

remains of organisms that lived long ago; specific conditions needed

permineralization

minerals carried by water deposited around hard structure

natural cast

flowing water removes original tissue, leaving an impression in the rock

trace fossils

record the activity of an organism (footprints)

amber preserved

organisms trapped in tree resin; hardens after tree is buried

preserved remains

organism becomes encased in material (ice)

radiometric dating

estimate age of fossils by calculating the decay of unstable isotopes

half life

amount of time it takes for the isotope to decay to half its original value

relative dating

estimates time which organisms lived; compares fossil placement in rock layers; scientists can then infer order species existed

index fossils

determine relative rock layer age; existed during specific time, large geographic areas: include fusulinids & trilobites

evolution evidence

fossils, geography, developmental similarities, vestigial structures/structural patterns, homologous structures, data

vestigial structures

remnants of organs/structures from early ancestors that no longer function in an organism

homologous structures

similar structure, different function, indicate common ancestor

analogous structures

different structure, similar function, no evidence of common ancestor