Bio Exam 1 Vocabulary/Concepts

fitness

the ability to produce viable offspring

adaptation

a heritable trait that is associated with high fitness

theory

an explanation or set of hypotheses that attempt to explain a large and pervasive phenomenon

evolution

a change in the frequencies of alleles in a population over time

genetic drift

any change that occurs in allele frequencies that is due to change

founder events

an event that can cause genetic drift when a relatively small number of individuals disperse to a new habitat and found a completely new population

genetic bottleneck

an event that can causes genetic drift when a species undergoes a large and rapid decrease in population size due to a disease epidemic, catastrophic storm, or other change

gene flow

an evolutionary process that changes allele frequencies through the movement of individuals and their alleles from one population to another - homogenizes allele frequencies among populations

maladaptive

leading to lower fitness

mutation

any change in the base sequence of DNA and thus a change in genetic information - introducing new alleles into population

speciation

the process of genetic isolation and genetic divergence that is responsible for the creation of a new species

species

an evolutionary independent unit in nature - meaning a population or group of populations that is genetically isolated from other and is thus changing under the effects of natural selection, genetic drift, and mutation independently of others

population

a group of individuals from the same geographic region that regularly mate together

fossil record

consists of any trace from an organism that lived in the past

extinction

when a species ceases to exist - there are no living members of a species left

endosymbiosis

when another organism lives inside the cells of another (inside-together-life)

mutualistic

when a relationship has provided fitness benefits for both organisms

adaptive radiation

the rapid diversification of a single lineage into a large number of species (for the purpose of adaptations that will allow the exploitation of different resources and habitats)

niche

the range of resources that a species can use and the range of environmental conditions it can tolerate

morphological innovation

a novel trait that allows individuals to exploit resources in a new way

ecological opportunity

when species thrive in regions with specific resources they are already fit to exploit and the ability to fill particular niches

alga (algae)

any photosynthetic organism that lives in an aquatic environment

protist

any eukaryote that is not a fungus, animal, or land plant

plasmid

a small, extrachromosomal loop of DNA

peptidoglycan

a structural carbohydrate found in bacterial cell walls - a lattice made of sugars linked with glycosidic bonds that have short chains of peptide-bonded amino acids protruding from them

prokaryote

bacteria and archaea - organisms whose cells lack a nucleus

microbe

viruses and any microscopic organism - including bacterial, Archaean, and eukaryotic species

primary producer

an organism that produces its own food, usually via photosynthesis

microbiome

the collection of microbes that lives in a particular location

phylogenetic tree

a graphical depiction of evolutionary history or phylogeny

homologous traits

any characteristics, ranging from a single nucleotide in DNA to body parts, that is observed in multiple species and inherited from the same common ancestor

root

the base of a tree, indicating the common ancestor of all the taxa indicated at the tips

node

a split where a speciation event occurs, so one species splits into two

branch

a species or other group changing through time

tip

the end of a branch, representing a taxon

taxon (taxa)

a named group of organisms

monophyletic group

an ancestor and all of its descendants

synapomorphy

a trait that one group has no that no one else does - defines monophyletic groups

homoplasy

similarity in traits that is no due to common ancestry but due to independent evolution

outgroup

any lineage that is not part of the monophyletic group that is the focus of a phylogenetic tree

parsimony

any criterion in logic that states the simplest explanation is the most likely to be correct

physiology

the study of systems that allows organisms to fulfill functions such as processing food and waste, reproducing, and defending against disease

proximate causation

explanations that focus on the molecular and cellular mechanisms responsible for a function

ultimate causation

explanations that focus on why structures and processes observed in an organism exist in terms of their evolutionary history and impact on fitness

cell

membrane bound structure that form the most fundamental functional unit of life

tissue

a group of cells that perform a common function within the same structure

organ

two or more tissues that create a structure with specific function