Honors biology 2 ch22

What is allopatric speciation

speciation by geographic separation (without father)

What is simpatric speciation

with father, same location

what is vicariance

a geologic event that causes speciation

what is an example of vicariance

a river changes course or continents break apart

what is dispersal

organisms move to a new location

what is microevolution

populations that change allele frequency over time

what are examples of microevolution

genetic events, environmental factors, and sexual selection

how did Darwin Contribute to the discovery of phylogeny

his observations led to him theorizing that species are modified descendants of earlier ones

how are these species become multiple descendant species

distinct populations separate and diverge over time leading to multiple species

what are phylogenies

hypotheses of evolutionary relationships

what are sister groups

groups on a phylogenetic tree that are more closely related to each other than either is to anything else

what is a paraphyletic group

a group that includes an ancestor and some, but not all of its descendants

what is a polyphyletic group

a group that does not include common ancestors

what is a monophyletic group

a group that includes a common ancestor and all its descendants

what is a monophyletic group

a group that does not include the common ancestor

what is an explanation/hypthesis

a way to make sense of individual observations

how were organisms grouped before evolution

by shared characteristics that are not always biologically accurate, or culture, such as wings being based off other parts on bats and birds

why were these classifications problematic

there were same names for different organisms or different organisms, such as a moose/elk

Why are scientific organism names important

similar or different cultural names may cause confusion in research

what are the order of hierarchy of taxa

Domain, Kingdom, Phyhlum, Class, order, family, genus, species

what is binomial nomenclature

the genus and the species

what is a character

a feature found in an organism

what are homologous characters

characters present in groups descended from a common ancestor

what are analagous characters

characters that arose due to similar selective environments, convergent evolution (ex. bird and bat wings)

what are synapomorphies

shared derived characters that arose from a common ancestor

where do monophyletic groups originate from

synapomorphies, as they are the basis for recognizing taxa in phylogenetic hypotheses and taxonomic classifications

what is parsimony

choosing the simpler of two or more hypotheses

how is molecular data used to identify common ancestors

the amount of changes of each taxa is identified in a DNA strand

what is true when evolutionary rates are constant

A and B become closer together than they are to C

what is true when evolutionary rates are not constant

distance based phylogeny is impossible due to different rates of change

what is a practical use of phylogenetic trees

they can be used to track carriers of a disease back to its origin point i.e. AIDS

how do fossils form

A hard part of an animal dies in a certain location, resisting decay

what is in the oldest level of fossils

slopes made from mud in the seafloor containing early arthropods

what occured in middle layers

limestone accumulated about 335 million years ago, burying and preserving marine animals

What occured in upper layers

white beds containing tracks of vertebrates occur

what is the geologic timescale

the series of time divisions that mark Earth’s history based on evidence to show how life on earth evolved

What is radioactive decay

the process of radioactive isotopes decaying into other elements, i.e. Uranium or Carbon-14

what is the advantage of a fossil record

they show evidence of extinct species, as well as the time period and environmental context that help us understand ancestors of said organism

how do fossils help with phylogeny

they fill in gaps in phylogenetic trees

How is the history of earth discovered

sedimentary rocks show changing state of earth, its environment, and live have changed over time

what are plate tectonics

tectonic plates that move around the earth, causing land to move and oceans or mountains to form

what is an example of plate tectonics

central Pangea was arid, resulting in continents splitting, and similar species being found in South America and Africa

what are mass extinctions

rare extinctions where large numbers of important species groups, resulting in new opportunities for evolution

what was the cretaceous extinction

an event that eliminated dinosaurs and resulted in the age of mammals

what was the permian extinction

the most devestating mass extinction event which occurred 252 million years ago with more than 90% of ocean life disappearing

what is the definition of phylogeny

the evolutionary history and relatedness of a group of organisms

what is a phylogenetic tree

a branching diagram representing a hypothesis about the evolutionary relationships among groups of organisms

what is a node

the point where a branch splits, representing the common ancestor from which the descendant species diverged

what are taxa (taxon)

another word for a group, such as a species, genus, or a family

what is a clade

a monophyletic group

what is a genus (genera)

a group of closely related species

what is a family

a group of closely related genera

what is an order

a rank of closely related families

what is a class

a rank of closely related orders

what is a phylum

a group of related classes

what is a kingdom

a group of related phylums

what is a domain

one of the three largest groups of life

what is a character

an anatomical, physiological, or molecular

what are character states

the observed condition of a character, such as the presence or absence of lungs

what does homologous mean

characters that are similar in different species because of descent from a common ancestor

what is a homology

a similar character in different species (noun)

what is an analogy

similar characters that independently evolved from each other

what are cladistics

phylogenetic reconstruction on the basis of shared evolutionary changes in characters

what is an outgroup

a group of organisms that have an older common ancestor than the common ancestor of the group of interest

what is radiometric dating

dating ancient materials using the decay of radioisotopes

what is a half-life

the amount of time it takes for a substance to reach half its original value

what was the Cambrian Explosion

a phase of rapid animal diversification that took place appoximately 541 million years ago by the Burgess Shale

what is a good method to remembering organism classifications

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