Test #2 (Semester 2) Flashcards
Natural Selection
process by which individuals that are better suited to their environment survive and reproduce most successfully; also called survival of the fittest
Common Ancestor
the shared ancestor of new, different species that arose from one population
Evolution (descent with modification)
change in a kind of organism over time; process by which modern organisms have descended from ancient organisms
Fossils
some sort of preserved remain of a life form (extinct or still alive)
Types: petrification, amber (sap), tar, ice, sedimentary rock)
petrification (mineralization)
when a structure trapped in sediments is replaced by minerals
relative dating
estimates the age of a fossil based on its placement in a layer of rock
radiometric dating
uses mathematical formulas to study the amount of radioactive isotopes in a fossil
why do isotopes decay?
they are unstable because they have the wrong number of neutrons
where are radioactive isotopes found
natural processes like solar radiation and star formation
half life
the amount of time it takes half a radioactive isotope to decay into a new stable element
C-14/U-238
C-14: carbon 14; becomes N in 5,730 years (used to study recent bones)
U-238 becomes Pb in 4.5 billion years (used to study petrified fossils)
John Baptiste Lamarck
Proposed that by using or not using certain body parts, an organism develops certain characteristics. He thought that these enhanced characteristics would be passed on to offsprings. “INHERITANCE OF ACQUIRED TRAITS”
ex: kangaroos didnt used to have big legs, giraffes stretched to get food
Why was Lamarck wrong?
Because the characteristics would have modified the DNA in order to be inherited and there is no evidence of this
Darwin
Father of EVolution
noticed that the plants and animals throughout the continent all had a definite South American character. They were distinct from the species of Europe. Even the fossils he found were unique. Some fossils were gigantic versions of modern day animals. His observations supported the idea that species living in SOuth America today were descended from ancestrial species on that continent
upbringing: men were doctors, interested in natural theology
gradualism
the slow processes of mountain building and erosion suggested an Earth that must be very old
these slow and gradual processes occurring over vast spans of time could cause enormous change on earth
Lyell
influenced Darwin greatly
gradualism
Galapagos
the islands Darwin went to
Thomas Malthus
essay explains how human suffering was due to the fact that populations grow faster than resources can be produced
All life must struggle/compete to exist
adaptation
a trait that allows an organism to survive in its environment
- help survive
- help attract a mate
homologous structures
similar structure found in more than one species that shared a common ancestor
vestigial structures
remnant of a structure that may have had a larger function in a species ancestors but has a lesser function today.
ex: whale hip bones, snakes leg bones
peppered moths
the dark moths live better in the dark forest/places with polution; the light moths live better in the ligh forest
pesticide resistant
if the bugs survive being sprayed with a pesticide, they will reproduce and have babies who are resistant to the pesticide
antibiotic restistance
the germ is resistant to medicine so it wont die and it will reproduce
