science unit test Flashcards
a group of similar organisms that can mate with each other and produce fertile offspring
species
finches
very different from island to island, most obvious were varied sizes and shaoes of the beaks. Each was well suited for the island it lived on.
adaptation
a trait that helps an organism survive and reproduce in its environment
evolution
the gradual change in a species over time, “Evolution by Selection means small changes in each generation
darwins conclusions about organisms on the galapagos
animals on the galapagos islands have different adapations that the animals on south america
a difference between indiviuals
variation
role of genes in variations
genetic variation: a difference between indiviuals of the same species
when organism creates more offspring that can survive
there is a struggle for existence’, or competition to survive
how does natural selecton lead to evolution
Organisms that are more adapted to their environment are more likely to survive and pass on the genes that made their success
homologous structures
similar body structures that realted species have inherited from a common ancestor,
evidence of evolution
similarities in body structure, comparative anatomy, himologous structures, fossil evdience,
fossils(how most form)
when an organism dies and becomes buried in sediment,
petrififed fossils
fossils in which minerals replace all or part of an organism, fossil tree trunks are an example of where minerals came out of a dissolved state and hardend in spaces of plant cells, thus preserving the wood
types of bodies or parts that become fossils are
Bones, teeth, shells, and other hard body parts
what is the main was species form
when animals in a species become isolated
diversity of speices because of
genetic diversity
mold
most common fossil, mold: hallow area in sediment in the shape of an organism, mold forms when hard part of organism, like a shell is buried in sediment
cast
most common fossil, solid copy of the shape of an organism, it is the opposite of a mold because minerals and sediment from water fill in the empty space of the mold
isolation
is when animals in a species get isolated from the rest
fossil age in sediment
by looking at the rocks they can tell how old the fossil is
scientific theory
a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment
natural selection
individuals that are better adapted to their environment are more likely to survive,
forelimbs of different animals
Humans, whales, lizards, and birds
sediment
fossils form in sediment, sediment is rock that helps keeps the fossils perserved,
punctuated equilibria
the idea that evolution occurs in spurts instead of following the slow, but steady path
precambrian time
the Earth formed, life arose, the first tectonic plates arose and began to move, eukaryotic cells evolved, the atmosphere became enriched in oxygen
plate tectonics
earths plates move slowly in various directions
how much movement of plates
1.5 centimeters (0.6 inches) a year
what does knowing speed of plate movement help with
helps us understand why and where events like earthquakes occur and volcanoes erupt
geologic time scale
the span of time is so great from the formation of earth to now, scientists use a type of calendar to divide history into long units of time
supercontinent
pangea
cambrian explosion on life forms
major animal groups started to appear
amphibians
any organism that is able to live both on land and in water
mass extinction of dinosaurs
asteroid impact
precambrian organisms
worms, jellyfish
why does australia have unique animals
isolation
what are two ways that continental drift could affect evoultion
species got separated by seas and oceans and speciation occurred
