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4.6 billion years ago-540 à about 4 billion
a. first land plants
b. first amphibians
c. first reptiles
d. first birds
e. first angiosperms
f. first bees
g. first horses
the largest-bodied and some of the most morphologically complex of all animals
Origin of tetrapod limbs
H. sapiens evolved its distinctive traits in Africa and then dispersed throughout the world.No interbreeding between H. sapiens and H, erectus, or Neanderthals, or H. floresiensis
Ecology: the study of how organisms interact with each other and their environment
Quantifying the effects of human impacts on the biosphere
air currents veer right (move clockwise) in the Northern Hemisphere and veer left (move counter-clockwise) in the Southern Hemisphere.
can be used to predict the actual or potential distributions of species
As the surface water moves away from the coast, it is steadily replaced by water moving up from the ocean bottom.
El Niño-Southern Oscillation (ENSO)
A) both metapopulations and extinction
B) both extinction and emigration
In the hypothesis that C. stellatus (a species of barnacle) is competitively excluded from the lower
intertidal zone by B. balanoides (another species of barnacle), what could be concluded about the
B) The fundamental and realized niches of B. balanoides are different, but the fundamental
and realized niches of C. stellatus are identical.
C) The fundamental and realized niches of B. balanoides are identical, but the fundamental
and realized niches of C. stellatus are different.
Species richness is the number of different species represented in an ecological community, landscape or region. Species richness is simply a count of species, and it does not take into account the abundances of the species or their relative abundance distributions. In contrast, morphological diversity takes into account both species richness and species evenness.
How would you describe the the distribution of biodiversity across the Tree of Life? What branch of biology studies factors which produce these patterns?
Organisms are divided into eukaryotes, bacteria, and archaea. Eukaryotes include multicellular lineages such as animals, plants, and fungi, but they also include single-celled lineages (protists).
Lampreys ~40 species. Chichlids>1600 species
Lampreys has a weaker species richness
>375,000 described species.
Beetles have more richness than vertebrates.
We compare them to sister clades who didn’t feed on angiosperms.
It has happened more than once and it’s easy to make a connection between five points rather than one.
When did dinosaurs exist and why did they go extinct?
230-65MYA. Asteroid because of the Iridum content after asteroid; the climate was dramatically changed + widespread fire.
Large time frame to test. In that time frame, thereare many variables that can’t be controlled and understood.
A good macro evolutionary hypothesis makes testable predictions using phylogenies.
Racial senescence: lineages that get old, get extinct
Insect/mammal competition: Insects and smaller mammals ate all their plants so they outcompeted dinosaurs
Dinosaur Diversity did not decrease as mammals and insects radiated before 65mya.
Evidence: A thick rock layer with high iridium content 10-miles; a huge impact crater beneath the northern coast of the Yucutan peninsula.
How can asteroids or volcanic activity cause a mass extinction?
Volcanic eruptions: Ash and SO2 are injected into the atmosphere, which blocks sunlight sunlight and results in cooling. Changes in temperature may cause extinction.
Meteroite: The resulting tsunamis, debris plumes that blocked the sun, and massive fires had a devastating effect on biodiversity.
Hippopotami; The common ancestor was a four-limbed, semiaquatic mammal known as a "walking whale" that branched off into two separate directions -- anthracotheres and cetaceans. DNA
Microevolution focuses on: origin, maintenance, and loss of variation within populations, reproductive isolation and species formation, and interactions among individuals and within populations.
Macroevolution: The processes and patterns of originations, adaptations, and extinctions.
Macroevolution is the study of evolution at or above species level and micro evolution explains evolution within a species
Phylogenies are created by fossil records. They show when lineages appear and disappear. Thus when clades diversify there are many more lineages in that clade.
What are the problems with the fossil record?
What is the difference between a phylogenetic tree and a time tree?
A phylogenetic tree is a visual rep of the evolutionary history of populations, genes, or species. A time tree is a phylogentic tree that also shows thetime between the evolution of different species by taking into account multiple fossils and models of genetic evolution addition to normal phylogeny
Morphological or molecularcharacters that are determined to be key adaptations (synapomorphies) shared by a group, then the common ancestor of the group can be inferred to have that trait as well
Fossils can be dated to a certain time from geographic evidence, and this helps limit the range of time of splitting events on the phylogenetic tree
What is the tree of life?
Coined by darwin, is a huge phylogentic tree of all life showing the relatedness of all species through time. Such phylogenies provide a framework for studying diversity
-counts of species richness
-phylogenies + richness data
-spatial distriubtion of richness
Many different 4-bar shapes produce the same amount of output rotation in the upper jaw per degree of lower jaw rotation, a mechanical property termed Maxillary KT. KT describes jaw speed. KT is size independent. KT is an ecologically relevant mechanical property
Can partially decouple morphological and mechanical diversity within clades
Many morphological differences yield the same mechanical functions
Morphological diversity=lever variance
Mechanical diversity= KT variance
Cladogram is based on the relationship between different species but not to the level of detail of a phylogram. Cladograms have equal branch lengths and have no representation of length. Chronogram shows time.
monophyletc-groupings that include all of the descendants of an ancestor and only that ancestor-A, B, C, BC, ABC
paraphyletic consist of an ancestral species and some of its descendants, but not all of them
How is good classification related to phylogeny?
phylogeny provides a basis for reclassification (basis of phylogeny fossils, morphological similarity, dna similarity)
What are synapomorphies?
A derived form of a trait that is shared by a group of related species (i.e. one that evolved in the immediate common ancestor of the group and was inherited by all its descendants.
Traits that look alike, but are the product of convergent evolution, and not derived from a common ancestral trait.
How do we know what organism falls on the phylogenetic tree?
•molecular analyses of geneticmaterial
If two species are close competitors, and one species is experimentally removed from the
community, the remaining species would be expected to _____.
1. Precisely state hypothesis and list predictions
2. Design study that tests those predictions
What is an example of bioremediation?
adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen
decreased genetic difference between the two populations
one copy of a gene can perform the original function while other copies are available to take on new functions
The gametophyte is haploid and produces haploid gametes bymitosis.
Sporophytes are diploid and produce haploid spores by meiosis.
protists; refers to the monophyletic group that includes glaucophyte algae, red algae, green algae, and land plants; descend from a common ancestor that engulfed a cyanobacterium
ex. - rhodophyra (red algae)
Plants have to overcome 2 problems if they want to grow straight up:
1. Transporting water from tissuesthat are in contact with wet soils to tissues that are in contact with dry airand the force of gravity2.Becoming tough enough to avoid falling over in response to gravity and wind
-Symbiotic relationship between fungi and algae or cyanobacteria, in which the fungi possibly provide inorganic food or water and the algae or cyanobacteria provide organic food.
-Soredia is the asexual unit of reproduction