Geology Unit 2

Evolution

Change throughout time

Biological Evolution

accumulation of changes in DNA thu generations of offspring that is observable thru physical traits

What does evolution explain

the fossil record

microevolution

change in gene frequency on a small scale that is not observable to geologists and not in fossil record

macroevolution

accumuation of microevolutionatory changes observable thru new species, body fossils, and trace fossils

body fossil

remains of an organism

trace fossils

preserfed evidence of animal activity

fossil

evidence of life that is older than 11,000 years

biological species

members of a population that can breed and produce fertile offspring

What did Alfred Russel Walllace and Charles Darwin agree upon

natural selection as the way evolution happens

what does mechanism mean

the cause or process that explains how something happens

natural selection

organisms with helpful traits survive and reproduce more so those traits spread through the population

proccesses that drive evolutionary change

1. genetic mutations

2. gene miggration

3. genetic drift

4. natural selection

Genetic Mutation

caused by errors in replication whether good or bad

Gene migration

movement of genes between populations when organisms move and reproduce in a new place

genetic drift

chance( random events) changes how common certain genes are in a population

Natural selection processes include

sexual and artifical selection and adaption

sexual selection

use physical traits to choose mates

artificial selection

purposfully choosing inviduals for reproduction

adaption

individuals who are gentically prepared for the enviroment will survive

What are fossils sometimes called

figured stones

who coined the term fossils

Leonardo da Vinci

When where fossils recognized in building stones and mountains

15th centruy

where were fossils commonly found in the 15th centruy

building stones and mountains

What was one early explanation for fossils

Global deluge(flood)

Early belief about fossils?

they were divinely created miracles

Who was Nicholas Steno

danish scientish known as the father of geology

What did Steno first show about fossils?

fossils are the remains of once living organisms

what are tounge stones

fossils that Steno proved are shark teeth

How does a shark tooth become a fossil?

exists in a livng shark, then gets buried by sediment and becomes a fossil over time

What did people belive about tounge stones before Steno?

They were natural rock formations, fell from the moon, or objects with magical emdical properties

what studies did the ID of fossils lead to ?

Classification schemes a evolutionary studies

Who is Linneaus

Scientist who develoepd the 1st classification system

What were the three original groups in classifcation system?

Animals, plants, and minerals

What type of non living things are included in Linneaus classification system?

rocks, minerals and fossils

what is classifcation system?

process of organizing organisms inton groups based on similarities

what is nested hierarchy

system where organisms are grouped into levels with larger groups.

how did Linneaus orgnaize organisms?

based on shared physical characteristics

who is George Cuvier

scientist who studied fossils and ancient life

How did Cuvier view fossils?

as evidance of life

How did Cuvier contribute to classification?

he included plants and animals

What major idea did Cuvier argue for?

exctinction

What did Cuvier study that led him to the idea of exctinction?

Megafauna (giant mammals)

why is the fossil record inherintley biased?

only a small percentage of organisms actually get fossilized

why dont most organisms become fossils?

challanges in preservation

what happens to soft parts of organisms after death

they decay quickly

which part of an organism is most likely to fossolize?

hard parts like bones and shells

What enviromental factors can destroy remains before fossolization?

scavangers and high energy enviroments

what is needed for fossils to form

rapid burial

under what conditions can soft parts be fossilized?

low oxygen and rapid sedimentation

what is the principle of fossil successin?

fossils appear in consistent order in rock layers overtime

what can fossils succesion be used for

to reconstruct the story of life on earth

what does fossil succesion help scientists assign?

relative ages of rock layers

what does fossil succesion show about species?

how species evolve overitme step by step

what are evolutionary patterns

ways that species change voer time

example of fossil used in fossil succession

trilobites

what type of fossil is a trilobite

palezoic index fossil

what are index fossils used for?

determining age of rocks as they are widespread, easy to identify, and lived for a short period of time

what does it mean evolution goes in one direction?

species change over time adn do not revert back to earlier forms

why must index fossils have lived for a short time?

so they help pinpoint a specific time period

transitional fossils

fossisl that show characteristics of both ancestors and descendents

paelrobiogrogrpahy

the study of grographic distrubution of organisms in the past

what determins the geographic distrubution of organisms?

the enviroment to which they have adapted

how are fossils used in paleobiogeography

they help reconstruct plate tectonics

what are homologous structures?

structures that are the same in orgin but have diffrent functions

what do homologous structures show?

that organisms shared a common ancestor

what does similar developmental biology suggest?

that organisms develop the same structures from a common ancestor

what type of organisms are huamns calssified as?

tetraoids

what do humans share with fish and amphibians

similar structural features (bones)

What does “same bones, diffrent organization and use” mean

structures come from a common ancestor but are adapted for different functions

what are analogous structures?

structures that evolved independeantly but have similar functions

what is similar in analogous structures?

their function

what is diffrent in analogous structures

their structure and orgin

example of anlogous structures

the wings of a bat, bird, and butterfly

Vestigial structures

features inherited from ancestors that have little or no function today

where do vesitigal structures come from

ancestors

example of a vestigial structure in a whale?

pelvic bone

example of vestigial structure on a penguin

wings

speciation

formation of a new species from an ancestral form

phylogeny

the evolutionary history of organisms (tree of life)

what is phylogeny based on?

shared characteristic and common ancestors

cladogenesis

type of speciation where once species splits into two or more species

clade

group of organisms that share common characterists and a common ancestor

punctuated equilibrium

pattern of evolution where species reamin stable for long periods then rapidly change

when do rapid changes occur in punctuated equilibirum?

during short periods of enviromental change

what happens during stable enviorments?

little to no evolutionary change

anagenesis

evolution within a single species without splitting

what happens to the orginal species in anagenesis

it gradually changes into a new species

cladogenesis

evolution where one species splits into two or more species

exctinction

permenant termination of a species

what is background excttinction?

normal ongoing rate of exctinction

what is mass exctinction?

a rapid widespread loss of many species

percent of organisms that are exctinct

99%

how long do species typically exist?

about 50,000 to 11million years

how long have humans(homosapies exsited)

300,000 years

what is the 5 mass exctinction

spike of exctinction rate in 40% or more

how does excitiction affect evolution?

leads ti soecuatuin as it opens up enviroments, food sources, and habitats

What was the atmosphere like on early earth

no oxygen so life couldnt survive

when did the oceans form on earth?

4.3 billion years ago

what are hydrothermal vents

openings on the ocean floor that release hot mineral rich water that were a safe refuge where early life could form and survive