Evolution

species

A group of similar organisms that can breed and produce fertile offspring.

Evolution

The gradual change in a species over time

Variation

Any difference between individuals of the same species.

Overproduction

organisms produce more offspring than can survive

Adaptation

A trait that helps an organism survive and reproduce

homologous structures

similar structures that related species have inherited from a common ancestor

Fossil

The preserved remains or traces of an organism that lived in the past

Law of Superposition

The geologic principle that states that in horizontal layers of sedimentary rock, each layer is older than the layer above it and younger than the layer below it.

half-life

length of time required for half of the radioactive atoms in a sample to decay

radioactive dating

A technique used to determine the actual age of a fossil on the basis of the amount of a radioactive element it contains

cast

A type of fossil that forms when a mold becomes filled in with minerals that then harden

mold

A type of fossil formed when a shell or other hard part of an organism dissolves, leaving an empty space in the shape of the part.

Unconformity

A break in the geologic record created when rock layers are eroded or when sediment is not deposited for a long period of time.

petrified fossil

a fossil in which minerals replace all or part of an organism

relative dating

Method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock

Sedimentary

Rock formed when layers of sediments were pressed and cemented together. Most fossils found in this type of rock.

survive and reproduce at a greater rate than other organisms.

Organisms with traits well suited to the environment will

helpful variations accumulate among surviving members of a species.

How does natural selection lead to evolution?

They evolved from a common ancestor

If two organisms look very similar during their early stages of embryological development, this shows...

A dead organisms becomes buried in sediment.

How most fossils form

Having hard parts like shells or bones

What makes a good fossil?

geographic isolation

How can a new species form?

geographic isolation

form of reproductive isolation in which two populations are separated physically by geographic barriers such as rivers, mountains, or stretches of water

branching tree diagram

A diagram that shows probable evolutionary relationships among organisms and the order in which specific characteristics may have evolved.

vestigial structures

remnant of a structure that may have had an important function in a species' ancestors, but has no clear function in the modern species.

Genes

DNA segments that serve as the key functional units in hereditary transmission.

relative age of rock

age compared with ages of other rocks

Law of Cross-Cutting Relationships

An igneous rock, fault, or other geologic feature must be younger than any rock across which it cuts.

radioactive decay

the process in which a radioactive isotope tends to break down into a stable isotope of the same element or another element

Precambrian

Name for the time in Earths early history that accounts for ninety percent of earth's time, but only cellular organisms lived. Single celled anaerobic prokaryotes.

Paleozoic Era

the part of geologic time 570-245 million years ago ; invertebrates, fishes, amphibians, reptiles, ferns, and cone-bearing trees were dominant

Mezozoic Era

251-65 mya, coral reefs, dinosaurs, flowering plants and insect diversified

Cenozoic Era

era that began about 66 million years ago, known as the "Age of Mammals"

Petrification Fossil

minerals replace wood or organism to create petrified wood or mineralized fossil. it replaces both hard and soft parts to cell level sometimes

Buried in sediment

Most fossils form this way

Does evolution allow for adaptation to the environment?

Yes over time, the best traits suited for an environment tend to survive and thrive and produce offspring with those favorable traits. Eventually it could lead to a change in the appearance of an organism and we call that speciation.

For which animals was Darwin known in the Galapagos?

Finches-mostly their beaks

How do absolute and relative dating differ?

Relative- determining whether a fossil is younger or older based on the layer of rock it is found, absolute- calculating the ratio of unstable atoms to stable atoms within a rock or fossil

What does the fossil record show?

They show a physical representation of what organisms looked like throughout Earth's history. It gives us clues as to how organisms evolved over time.

How is the age of a fossil estimated?

It is aged to be the same as the rock layer that it is found within. Rock age can be determined relatively by being older/younger than surrounding rock or by absolute dating. By measuring the unstable elements in the rock that holds the fossil and the fossil itself and comparing the decay to the known rate of decay of the elements.

How old is the Earth?

4.6 billion years old

In addition to Natural selection, what is also taken into account when explaining evolution?

Genetic inheritance

In what kind of rock do fossils form?

Sedimentary

petrified remains (fossils)

the process of turning living organic material into stone. This process takes place when the molecules in an organism are replaced with the molecules of a mineral.

Carbonaceous fossil

thin film resembling a silhouette/made from the soft tissues of an organism. is an organism outline of a fossil. It is a type of fossil found in any rock when organic material is compressed, leaving only a carbon residue or film.

molds (fossil)

a fossilized impression made in the substrate - a negative image of the organism

Casts fossils

formed when a mold is filled in

Original Remains Fossil

unchanged remains of plants and animals

trace fossil

various tracks, trails and burrows. They range from worm burrows to dinosaur footprints. They give us information about what the animal did while it was alive. For example, we can learn how animals moved or fed.

List some evidence for evolution

embryological similarities, Similarities in DNA, similar skeletal structures, fossil record, vestigial structures, homologous structures

Under what conditions do fossils form?

A trace or imprint of living things that preserved in rock or amber /Organism must be preserved, hard parts are best, soil must quickly cover the organism

What are the 4 parts of Natural selection?

Overproduction of offspring, genetic variation, struggle to survive, successful reproduction. When the individuals in a population have traits that give them a competitive edge over other population members, they are more likely to survive.

What is a half-life?

The time it takes for half of a radioactive sample to decay

What is a mutation?

A change in a gene at the DNA level

What is a species?

A group of organisms that can mate and have fertile offspring

What is adaptation?

a change or the process of change by which an organism or species becomes better suited to its environment.

What is evolution?

The process by which organisms change over time by passing traits to their offspring

What is our best guess as to how evolution takes place?

Natural selection

What is speciation?

Formation of a new species by separation, adaptation and division. Normally to begin speciation, a newly formed mountain, canyon or lake may occur.

What major organisms lived during the Cenozoic Era?

flowering plants, age of mammals

What major organisms lived during the Mesozoic Era?

Plants, fish, dinosaurs

What major organisms lived during the Paleozoic Era?

Ferns, corals, primitive vertebrates

What major organisms lived during the Precambrian Era?

Precambrian, anaerobic prokaryotic cells (don't use oxygen and don't have a nucleus)

What is an unconformity?

Rock layers that has been lost due to erosion

What is the principle of superposition?

States that oldest layers of rock are laid down below younger layers in horizontal layers

What are the time divisions from broadest to most specific

Eon🡪era🡪 period🡪 epoch

What are some types of major extinctions

Catastrophic methane release (Holocene), huge volcanic eruptions for many years( Permian-Triassic/Triassic-Jurassic)), climate change

( Ordovician-Silurian/Devonian), impact of asteroid (Cretaceous-Paleogene)

What is an intrusion?

states that the geologic feature which cuts across another is the younger of the two features. It is a relative dating technique in geology. Diagonal or vertical are dykes and horizontal are sills.