Div I Exam 1

variation at all levels of biological organization

biodiversity

types of biodiversity

genetic, ecological, organismal

species-level biodiversity

organismal biodiversity

the largest scale of biodiversity, ecosystem-level

ecological biodiversity

the smallest scale of biodiversity

genetic diversity

diversity on a local scale; within a particular area/ecosystem 

alpha diversity

turnover rate between ecosystems, involves the count of species that are unique to just one of the two ecosystems

beta diversity

overall regional diversity; large-scale

gamma diversity

hierarchical filing system that organizes all organisms

Linnaean hierarchy

how biodiversity is studied, mostly using evolutionary lines

systematics

simplified visualization of a taxon's evolutionary history, typically shows progression from ancestral to most evolutionarily derived 

cladogram

newly derived character state shared by all members of a taxon, chosen by distinctive morphological traits 

synapomorphy

a group all derived from a common ancestor

clade

includes most recent common ancestor and all its descendants (clade) 

monophyletic group

includes a common ancestor and some, but not all, of that ancestor's descendants 

paraphyletic group

grouping derived from more than one common ancestor (better to refine these into monophyletic groups)

paraphyletic group

a taxon that serves as a reference group for other taxa in a cladogram; relatively closely related, but not too closely 

outgroup

applied, goal-oriented science that focuses on protecting and restoring Earth's biodiversity and natural ecosystem

conservation

____ for conservation are economic benefits from consuming or experiencing a resource; includes timber, medicinal plants, ecotourism 

use values

____ for conservation are values associated with natural resources that does not concern human use or economic benefit

non-use values

conservation "in the wild," includes establishing protected areas and restoring ecosystems

in situ

conservation in captivity/controlled environment; includes seed banks, zoos, and culture collections

ex situ

when a species is only found in a single limited area 

endemism

endemism ___ from poles to equator

increases

endemism peaks on ____

remote islands

alpha, beta, gamma are ____ of biodiversity

spatial patterns

number of species in a given area

species richness

abundance of each species in a given area

species evenness

percentage of described extant species that are vertebrate animals

2-3%

percentage of described extant species that are plants

18-20%

percentage of described extant species that are invertebrate animals

66%

percentage of described extant species that are fungi

8%

percentage of described extant species that are bacteria

<1%

total count of described extant species on Earth

1.5-2.5 million

singular reference specimen for a species

holotype

identical specimen collected at same time and place as holotype 

isotype

identical specimen collected at different time or place than holotype 

paratype

ecological principle stating that larger geographic areas contain a greater number of species

species-area relationship

method of measuring biodiversity that uses patterns of description to estimate cumulative unknown species 

patterns of species description

one can use ____ where species number is well known to estimate biodiversity over larger areas 

well studied areas

quantitative measures of diversity using richness, evenness, and dominance as core components

diversity indices

measures uncertainty or entropy in predicting the species identity of a randomly chosen individual, factoring in both richness and evenness

shannon-wiener index (H’)

the first person in Western science to create a formal system for grouping and organizing living things, introduced early versions of genus and species, divided organisms into plants vs. animal

aristotle

first to organize like organisms in genera

greeks and romans

period during which the polynomial system was invented, when people began using Latin to record names (AD 500-1500)

Middle Ages

descriptive terms added to genus name to refer to a particular organism, could become very long

polynomial system 

modern system for describing a particular organism using two words (genus species)

binomial system

developed the binomial system

carolus linnaeus

holotype, isotype, and paratype are all types of ____, which are deposited when describing a new species

type specimens

first step to describe a new species, in order to document evidence

take photos and DNA samples

second step to describe a new species, in order to document analysis

observe morphology and record a description

third step to describe a new species, in order to ensure the species has not already been described

check field guides

fourth step to describe a new species, in order to consult others with your findings

send description, photos, and samples to experts

fifth step to describing a new species, after receiving confirmation that the species is not already described

deposit a type specimen

sixth and final step to describe a new species

publish name and description in a peer-reviewed journal

shows the evolutionary relationships and history among different species or groups of organisms

phylogenetic tree

lines connecting the nodes and tips of a phylogenetic tree that show the amount of genetic change or time passed

branches

the endpoints of the branches on a phylogenetic tree that represent the specific species, organisms, or taxa being studied (leaves)

tips

the places where branches on a phylogenetic tree split, representing a common ancestor shared by the connected lineages (branch points)

nodes

the single ancestral lineage at the base of a phylogenetic tree that connects all organisms on the tree, representing their most recent common ancestor

root

largest division of geologic time, spanning hundreds of millions to billions of years

eon

four eons of Earth’s history

Hadean, Archean, Proterozoic, Phanerozoic

subdivision of an eon, lasting tens to hundreds of millions of years; typically separated by major changes in Earth's life forms, climate, and geology

era

subdivision of an era, lasting tens of millions of years.; characterized by specific rock systems and significant biological or regional events

period

subdivision of a period, lasting from several million down to tens of thousands of years; describe finer environmental and evolutionary shifts

epoch

age of Earth

4.5 billion years

Earth’s second eon: low oxygen environment, rock formations rich in iron, first life forms during this time, 4.5-2.5 billion years ago

precambrian archaean eon

Earth’s third eon: great oxygenation event and the evolution of the first eukaryotes occur during this time, 2.5 billion-570 million years ago 

precambrian proterozoic eon

chemoautotrophic prokaryotes, the first life on Earth and the first photosynthesizers on the planet

cyanobacteria

Earth’s fourth eon: 542 million years ago-present, commenced with the Cambrian Explosion, a rapid diversification of multicellular life and shelled organisms

phanerozoic eon

most major animal phyla appear, Earth dominated by marine life

cambrian explosion

Earth’s current period, marked by repeated ice ages, climate fluctuations, and the eventual rise of human civilization

quaternary period

oppositions to maintaining biodiversity

economic growth, resource extraction, cost and resource allocation

reasons to maintain biodiversity

ecosystem services, medicine/health, ethics, aesthetics, balance

the five extinction level events

end ordovician, late devonian, permian, end triassic, cretaceous-tertiary

Earth’s first and second most severe extinction event; happened in two distinct phases that wiped out about 85% of marine species, global cooling and massive glaciers formed, followed by a rapid warming and sea-level thaw

end ordovician

Earth’s second mass extinction event; oceans lost oxygen on a global scale (anoxic events), turning large areas into toxic dead zones; roughly 75% of species vanished, heavily impacting reef-building organisms and tropical marine life

late devonian

Earth’s third and most deadly extinction event; massive volcanic eruptions in Siberia triggered extreme global warming and made oceans acidic, killed 96% of marine species and 70% of land vertebrate species

permian

Earth’s fourth extinction event, volcanic activity tied to the breakup of the supercontinent Pangaea caused intense global warming and carbon dioxide spikes, 76% to 80% of species went extinct which allowed dinosaurs to become dominant

end triassic

Earth’s fifth extinction event, massive asteroid struck the Chicxulub region in modern-day Mexico, triggering wildfires, earthquakes, and blocking out the sun with dust, killing all non-avian dinosaurs

cretaceous-tertiary

Earth’s potential sixth extinction event, the ongoing, human-driven loss of plant and animal species across the globe

Anthropocene/Holocene Extinction

period of fungal and plant colonization that occurred 470 million years ago

ordovician

three eras of the Phanerozoic eon

paleozoic, mesozoic, cenozoic

the hadean, archaean, and proterozoic eras are considered ____

precambrian

two major causes of extinction events

changes in atmospheric makeup, volcanic eruptions

caused by excess O₂ in atmosphere

freezing

caused by excess CO₂ in atmosphere

heating