Test One Flashcards
Population undergoing natural selection
- Individuals of a given age will differ predictably from the individuals which do not survive that age.
- The offspring of a given generation will differ predictably from their parents
Adaptive radiation: examples would be?
Two animals that are genetically related, but occupy different purposes.:
Ex: honeycreepers and Tasmanian wolf.
Bottleneck
Species do not very much. They pass through a funnel.
Three models of natural selection
Stabilizing, disruptive, and directional
Stabilizing selection
Outcome that is in favor of average values of the trait and to disfavor extreme traits
Disruptive selection
Disruptive selection in which two different extreme phenotypes are simultaneously favored, but their average is disfavored. This creates two very different phenotypes that dominate the environment
Directional selection
Favors a phenotype value either above or below the average and causes the population to shift toward the favored value over time.
Evolution
Any change in the genetic constitution of a population of organisms. Anything from small to large.
Evolutionary force
Any factor in the external environment or in the bodies of the organisms themselves that induces shifts in the frequency of genes within a population
Evolution to Darwin was
Descent with modification
Theory
A set if statements or principles devised to explain a group of facts or phenomena, eapecially one that has been repeatedly tested or is widely accepted and can be used to make predictions about natural phenomena
Inheritance
If a trait cannot be inherited, it cannot be passed on
Balenced polymorphism
A special type of genetic polymorphism I which two or more alleles persist in a population over many generations as a result of natural selection. Heterozygous traits maintain the recessive gene when dominant
Cline
Measurable gradual change over a geographic region in the average of some phenotype or genotype character such as color size and gene frequency.
Jean-Baptiste Lamarck
Soft Lamarckism
Lamarckism
Born 1 aug 1744-18 dec 1829
Came up with the theory of inheritance of acquired characteristics
Ex of NS malarial flies
Fly into huts Bite someone Land on wall to digest meal Walls then sprayed with DDT flies quit landing in wall Hit ad run mosquitoes
NS EXAMPLE Culex pipe a
Insect developed an antidote for insecticide which is digested by esterases
Carry 250 different alleles for resistance
Gradualism
Small differences are the raw material from which the different major forms of life evolved.
Phenotypic gradualism
New traits, even those that are strikingly different from ancestral ones, are produced in a series of small, incremental steps
Punctuate equilibrium
Phenotypic evolution is. Concentrated in relatively brief events of branching speciation, followed by much longer intervals of evolutionary stasis
Sexual selection
Used to denote the selection of traits that are advantageous for obtaining mates but may be harmful for survival
Fitness
The total number of an individuals direct and indirect fitness; includes the genes contributed directly to offspring and those contributed indirectly by kin selection
Adaptation
The condition of showing fitness for a particular environment as applied to the characteristics of a structure, function, physiology or the entire organism and the process by which fitness is acquired by an individual.
Genetic drift
The evolution of the genetic constitution of a population by chance processes alone.
Example of genetic drift
There is 50:50 chance that two Herero Aa will give a Aa or a homo allele AA/aa.
Founder effect
An extreme example of genetic drift: a small population colonizing a new area: bucket of marbles. Pronghorn
Hardy-Weinberg equilibrium assumptions
There is random genetic drift Random mating Mutations do not occur No migration No natural selection
Types of speciation
Allopatric, sympatric and stasipatric
Allopatric speciation
Lineage independence is achieved while two or more lineages are geographically separated. Eventually becoming two separate species
parapatric speciation
Lineage independence is achieved between geographically distinct lineages which maintain limited inter lineage mating across a contact zone. Form own species
Stasipatric speciation
Lineage independence is achieved by major chromosomal rearrangements which give rise to postmarking isolating mechanisms.
Sympatric speciation
LI is achieved w/o geog. Separation but by shifts in ecology, hosts, time of reproduction, or by hybridization: such as the same species in same environment but eat different types of plants leafs
An evidence of plate tectonics
Similar flightless birds all found on southern continents: rheas, ostrich, emu, cassowaries, elephant birds, moas, kiwis, tinamous
Pangea separated into to two
Laurasia and gondwana
Biogeographic realms
Nearctic- N. America
Neotropical- S. America
Palearctic- Russia and Europe+ small Africa
Ethiopian- most Africa
Oriental-Asia
Australian- Australia
Wallace’s line is between oriental and australian
Niche
Place occupied by a species in its ecosystem, where it eats, what it eats, foraging route.
Adaptive radiation
Term applied to the spread of species of common ancestry into different niches. Fishes African cichlids have minute differences dies to their niches. Also honeycreepers are another example(different beaks for insects or plants
Evolution convergence
Tasmanian wolf acts like a canine, but ha only adapted to fit a niche. It is more closly related to marsupials genetically.
Mayr did what
Coined the term species and summarized everything on the subject
Species
A lineage, a collection of organisms that share a unique evolutionary history and are held together by the cohesive of reproduction.
Permeating isolation mechanism
Seasonal, ethological, mechanical
Seasonal PIM
Potential mates do not meet
Ethological PIM
Potential mates meet but do not mate due to behavior
Mechanical PIM
Copulation attempted but no transfer of sperm takes place
PIM examples include
Empidonax flycatchers: habitat PIM
Postmating isolation mechanism
Gametic mortality
Hybrid inviability
Hybrid sterility
Zygotic mortality
Gametic mortality
Sperm transfer takes place but is never fertilized
Hybrid inviability
A postzygotic reproductive isolating mechanism in which the embryonic developement is aborted
Hybrid sterility
Zygote is fully viable but sterile(mule)
Zygotes mortality
Egg is fertilized but zygote dies
Eusocial animals
Queen and king systems of inbreeding
Sir Alfred Wallace
Same concept of natural selection at the same time Darwin produced such ideas/theory’s
Unique to humans
Art and abstract thinking
Ardipithicus ramidus
Indicates we never walked on knuckles
Australopithecus aferensis
Found in Ethiopia 3mya
Lucy
Australopithecus africanus
The taunt child discovered in africa
Australopithecus garhi
Scavenged lion, used tools to get to none marrow fat
Homo habilis
Koobi fara, kenya
2 myo
Skull found at dmansisi
Characters between h. Habilis and h. Erectus
It was surprising to find it out of africa
Comparisons of h. Erectus an h. Sapians
Same rib cage
Smaller hips
More robust bones
Small brain
Homo erg aster
Workin man who used many tools
Homo heidelbergensis
800,000 ya
Probably ancestor to both h. Sapians and h. Neanderthalensis
Homo neanderthalensis
Robust went after large game
Embryology key events
Gamete formation Fertilization Cleavage Gastrulation Organogenesis Growth
Spermatogenesis
Spermatogonium(diploid) Primary spermatocyte(diploid) Meiosis 1 Secondary spermatocyte(haploid) Meiosis 2 Spermatids Spermatozoa
Egg activation
- Acrosome contacts the vitelline membrane
- Sperm lysis create a hole in the vitelline membrane
- The lysis change the permeability of the plasma membrane to sodium ions
- Cortical granules discharge and the vitelline membranes begins to rise off the egg plasma membrane.
- The fertilization membrane is formed.
Only one sperm can enter or you will have a triploid
Morula
Solid ball of cells after cleavage.
Blastula
Hollow ball of cells.
Frog gastrulation 1
Holoblastic cleavage occurs with many cells fewer at the vegetal end
Frog gastrulation 2
Begins with formation of a groove( gray cresant) and the vegetal region of the embryo.
Frog gastrulation 3
Involution: cells spread from the animal pole toward the blastophore, and replace those moving into the interior of the embryo
Frog gastrulation 4
A ring-like blastophore now surrounds the protruding yolk filled cells near the vegetal end of the embryo.
Yolk plug
Protruding cells during frog gastrulation
Frog gastrulation 5
Rolling the endoderm and mesoderm cells into the blastophore forms the archteron
Frog gastrulation 6
Part I the last mesoderm cells to roll over the dorsal lip into the blastophore are the presumptive notochord. This mesoderm is referred to as the chordamesoderm. Thickening in the chordamesoderm are call somites
Frog gastrulation 7
In late gastrulation changes in the dorsal surface mark the formation of the neural tube( neuralation)
Amnion
Fluid filled sac that encloses the embryo and provides an aqueous environment in which the embryo floats protected from mechanical shock.
Allantois
Stores metabolic wastes. Functions as a respiratory surface for exchange of oxygen
Chorion
Lies just beneath the eggshell and completely encloses the rest of the embryonic system.
Oogenesis in humans
Oogonium(diploid) Synthesis Primary oocyte Meiosis 1 First polar body/ secondary oocyte Meiosis 2 Two are recycled, a second polar body, and an ovum(haploid) are produced.
The ovum is what gets fertilized by sperm.
Heart embryogenesis
Cardiac loop: heart tube is folded to form an s shaped dextro-ventral comvexity.
Heart formation 2
The atria are partitioned. The septum priming grows from the inferior part of the atria to the top, leaving a foramen called the ostium primum. The septum secundum comes from the top. The ostium primum will be closed by the fifth week
Simple Epithelium types
Simple squamous
Simple cuboidal
Simple columnar
Stratified squamous epithelium types
Stratified squamous epithelium
Transitional epithelium- unstretched
Transitional epithelium - stretched
Simple squamous epithelium
Flattened cells that line, blood capillaries lungs and places for passive diffusion of gases and tissue fluids
Simple cubidal epithelium
Square box like cells. Lines small ducts and tubules(kidney and salivary glands), has secretory and absorptive functions
Simple columnar epithelium
Rectangular boxes. Absorptive surfaces may be ciliated
Stratified squamous epithelium
Continuous reproduction of cells to maintain many layers for protection: oral cavity, esophagus, anal canal, and vagina of mammals
Transitional epithelium
Flexible and stretches to meet needs of transition
3 parts to cartlage
Chondrocyte(inner), in lacuna(surrounds chrondoctye), immersed in a matrix
Smooth muscle
Fuzzy long nuclei
Cardiac muscle
Round nuclei interspersed throughout
Skeletal muscle
Elongated nuclei in stratified rows. More orderly.
