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hypothesis
A hypothesis (from Greek '; plural hypotheses) is a proposed explanation for an observable phenomenon. TERM 2
theory
DEFINITION 2 a hypothesis that a consensus of community agrees is probably true because evidence supports the explanation offered and new evidence can't disprove it TERM 3
law
DEFINITION 3 universally accepted facts of the physical world TERM 4
intelligent design
DEFINITION 4 Intelligent design is the assertion that "certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection." It is a modern form of the traditional teleological argument for the existence of God, but one which avoids specifying the nature or identity of the designer. TERM 5
natural selection
DEFINITION 5 Natural selection is the process by which heritable traits that make it more likely for an organism to survive and successfully reproduce become more common in a population over successive generations. CHANGE IN ALLELE FREQUENCIES Occurs in individuals
adaption
Adaptation is the process whereby a population becomes better suited to its habitat. TERM 7
population
DEFINITION 7 individuals of the same species, living in the same area, at the same time TERM 8
descent with modification
DEFINITION 8 change over time produced modern species from ancestral species TERM 9
geological time scale
DEFINITION 9 time scale based on fossils TERM 10
vestigal trait
DEFINITION 10 Vestigiality describes homologous characters of organisms which have seemingly lost all or most of their original function in a species through evolution.
mutation
modifies allele frequencies by continually introducing new alleles TERM 17
heterozygote
advantage
DEFINITION 17 A heterozygote advantage (heterozygous advantage) describes the case in which the heterozygote genotype has a higher relative fitness than either the homozygote dominant or homozygote recessive genotype. TERM 18
directional selection
DEFINITION 18 In population genetics, directional selection occurs when natural selection favors a single phenotype and therefore allele frequency continuously shifts in one direction. TERM 19
stabilizing selection
DEFINITION 19 Stabilizing selection, also referred to as purifying selection or ambidirectional selection, is a type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait value. TERM 20
founder effect
DEFINITION 20 In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population.
population bottleneck
A population bottleneck (or genetic bottleneck) is an evolutionary event in which a significant percentage of a population or species is killed or otherwise prevented from reproducing. TERM 22
nonrandom mating
DEFINITION 22 results in inbreeding sexual selection TERM 23
hardy weinberg principal
DEFINITION 23 The Hardy-Weinberg principle states that both allele and genotype frequencies in a population remain constant-that is, they are in equilibrium-from generation to generation unless specific disturbing influences are introduced. TERM 24
biological species concept
DEFINITION 24 populations are evolutionary independent if they are reproductively isolated from each other and don't breed prezygotic and postzygotic TERM 25
morphospecies concept
DEFINITION 25 evolutionary independent lineages if they are different in size, shape, or other morphological features
sympatric speciation
In evolutionary biology and biogeography, sympatric and sympatry are terms referring to organisms whose ranges overlap or are even identical, so that they occur together at least in some places. TERM 32
polyploidy
DEFINITION 32 Polyploidy occurs in cells and organisms when there are more than two paired (homologous) sets of chromosomes. TERM 33
fusion of
populations
DEFINITION 33 gene flow occurs and may erase distinctions between the two populations TERM 34
reinforcement
DEFINITION 34 selection for traits that isolate populations reproductively TERM 35
hybrid
zones
DEFINITION 35 geographic area where interbreeding between two populations occurs and hybrid offspring are common. can lead to extinction but sometimes leads to origination of a new species
homology
traits that are similar due to common ancestry TERM 37
homoplasy
DEFINITION 37 occurs when traits are similar due to reasons other than common ancestry TERM 38
convergent evolution
DEFINITION 38 when natural selection favors similar solutions to the problems posed by a similar way of life common cause of homoplasy TERM 39
cambrian explosion
DEFINITION 39 The Cambrian explosion or Cambrian radiation was the apparently rapid appearance of most major groups of complex animals around , as evidenced by the fossil record. most evolutionary change in history TERM 40
hox genes
DEFINITION 40 help specify the location and shape of genes found limbs, antenna, and many other key structures "new genes, new bodies" hypothesis- number of hox genes expanded over time and appear to have been duplicated several times.. duplication of hox genes has been important in making the elaboration of animal body plans possible
landscapes
Landscape comprises the visible features of an area of land, including physical elements such as landforms, living elements of flora and fauna, abstract elements like lighting and weather conditions, and human elements like human activity and the built environment. TERM 47
biomes
DEFINITION 47 Biomes are climatically and geographically defined areas of ecologically similar climatic conditions such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. TERM 48
ecosystems
DEFINITION 48 The term ecosystem refers to the combined physical and biological components of an environment. TERM 49
littoral zone
DEFINITION 49 shallow waters along shoer TERM 50
limnetic zone
DEFINITION 50 The limnetic zone is the well-lit, open surface waters in a lake, away from the shore.
benthic zone
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean or a lake, including the sediment surface and some sub-surface layers. TERM 52
photic zone
DEFINITION 52 The photic zone or euphotic zone (Greek 'well lit') is the depth of the water in a lake or ocean, that is exposed to sufficient sunlight for photosynthesis to occur. TERM 53
aphotic zone
DEFINITION 53 The aphotic zone (aphotic from Greek prefix + "without light") is the portion of a lake or ocean where there is little or no sunlight. TERM 54
calvin cycle
DEFINITION 54 The Calvin cycle or Calvin-Benson-Bassham cycle is a series of biochemical reactions that take place in the stroma of chloroplasts in photosynthetic organisms. TERM 55
grana
DEFINITION 55 thylakoids stacked together. where ATP is produced
trophic levels
In ecology, trophic dynamics is the system of trophic levels (Greek , troph, food or feeding), which describes the position that an organism occupies in a food chain - what an organism eats, and what eats the organism. TERM 62
biomass
DEFINITION 62 Biomass, a renewable energy source, is biological material derived from living, or recently living organisms, such as wood, waste, and alcohol fuels. TERM 63
keystone species
DEFINITION 63 species that has a much greater impact on the surround species than it's abundance would suggest TERM 64
fundamental niche
DEFINITION 64 the ecological space that a species occupies in its habitat in the absence of competitors TERM 65
realized niche
DEFINITION 65 the ecological niche that a species occupies in the presence of competitors
inducible defenses
defenses only produced when threatened TERM 67
constitutive/standing defenses
DEFINITION 67 defenses that are always present ex: camouflage, mimicry TERM 68
life tables
DEFINITION 68 summarize how likely it is that individuals of each age class in a population will survive and reproduce TERM 69
survivorship
DEFINITION 69 proportion of offspring produced that survive to a certain age type1: young=high, old=low (humans) type2: steady (songbirds) type3: young=low, high= old (plants) TERM 70
fecundity
DEFINITION 70 number of female offspring produced
gametogenesis
formation of gametes TERM 77
acrosome
DEFINITION 77 head region of sperm- contains nucleus TERM 78
cortical
granules
DEFINITION 78 small vesicles filled with enzymes that are activated during fertilization- found in eggs TERM 79
vitelline envelope
DEFINITION 79 aka zona pullucida- glycoproteins that surrounds the egg. sometimes a jelly layer surrounds this to envelope the entire egg TERM 80
acrosomal reaction
DEFINITION 80 triggered by contact between the sperm's head and the jelly layer
cleavage
rapid cell divisions that take place after fertilization TERM 82
blastomeres
DEFINITION 82 cells created by cleavage divisions TERM 83
blastula
DEFINITION 83 the embryo consisting of a mass of blastomere cells, after cleavage is complete TERM 84
gastrulation
DEFINITION 84 Gastrulation is a phase early in the development of most animal embryos, during which the morphology of the embryo is dramatically restructured by cell migration, resulting in the formation of a gastrula TERM 85
germ
layers
DEFINITION 85 the three primary tissue layers resulting from gastrulation Ectoderm (outside), mesoderm (middle), Endoderm (inside)
notochord
The notochord is a flexible, rod-shaped body found in embryos of all chordates. TERM 92
neural tube
DEFINITION 92 In the developing vertebrate, the neural tube is the embryo's precursor to the central nervous system, which comprises the brain and spinal cord. TERM 93
somites
DEFINITION 93 A somite (or primitive segment in older texts) is a division of the body of an animal. form on both sides of the neural tube, down the length of the body TERM 94
determination
DEFINITION 94 when somite cells become irreversibly determined- they will eventually differentiate into a specific cell type, based on their location within the somite TERM 95
connective tissue
DEFINITION 95 Connective tissue is a form of fibrous tissue, provides packing material b/w organs and padding ex: bone, cartilage, blood
nervous tissue
consists of neurons, have projections that contact each other, regulate ion concentration TERM 97
muscle tissue
DEFINITION 97 functions with movement skeletal, cardiac, smooth TERM 98
epithelial tissue
DEFINITION 98 cover outside of body, cover surfaces of organs TERM 99
conformational homeostasis
DEFINITION 99 conforming to environment TERM 100
regulatory homeostasis
DEFINITION 100 adapting to the environment
