Term
|
Definition
| Gene frequencies will stay the same from one generation to the next unless something acts to change |
|
|
Term
| Hardy-Weinberg equilibrium holds if: |
|
Definition
-No net mutation
-Large population
-Mating is at random
-No net immigration or emigration
-In other words: genetic equilibrium=non evolution
|
|
|
Term
|
Definition
| in very small populations, events may cause large changes in gene frequencies. |
|
|
Term
|
Definition
where the surviving individuals of an large population re-populate an area with different gene frequencies than in the parent population. Original populations: 25 different alleles of a particular gene. Bottle Neck Effect—Cheetah population was affected by changing habitat and massacre by hunters—Repopulation occurs. Only 4 different alleles remain |
|
|
Term
|
Definition
| a small subset of a population may leave and create new population with a different gene frequencies |
|
|
Term
|
Definition
| One genotype becomes another→ new gene appears in population |
|
|
Term
|
Definition
| no longer produces fertile offspring, due to environmental change-→ |
|
|
Term
| Gene change: DNA molecules |
|
Definition
|
|
Term
| gene changes: Chromosomes, nuclei |
|
Definition
|
|
Term
| gene changes: Populations (gene pool) |
|
Definition
|
|
Term
| A few (of the many) things that we know that Darwin did NOT know: |
|
Definition
-Cell division and the sexual life cycle: mitosis, meiosis
-Mendelian genetics (segregation, independence) and “exceptions”
-Mutations
-Structure and function of genetic material (DNA→ RNA→ proteins→structure/function of individual organisms
-Gene pop concept and gene frequencies
-Hardy-Weinberg Principle
-Examples of “evolution in action”
|
|
|
Term
Charles Darwin (1809-1882)
|
|
Definition
British aristocrat. Father was MD Sent Charles to medical school where he got sick in anatomy lab. Left to study ministry. Father said he would never amount to anything. BA in 1831 and same year sailed to Beagle for 5 yrs. as a naturalist. Miserable on Beagle: small quarters; always seasick; always first ashore.
Received Lyell’s book on geology as he boarded. Intelligent, curious about organisms; mind for details; considerable drive and willingness to accept new explanations; took copious notes and collected volumes of data.
He read Malthus’ book on exponential growth of populations in 1838 and began to put his theory together in 1842, but continued to analyze data through mid 1850s without publication. Received draft of paper from Alfred Wallace on natural selection in 1858. They published their papers jointly in 1859 (Origin of Species).
|
|
|
Term
What Darwin observed (what we now know) 3 observations and a conclusion: |
|
Definition
-inheritable variations within populations, yet similarities within close relatives—he didn’t know why
-Overpopulation- Malthus’ idea, e.g. 2 elephants=19 million in 750 years
-Limiting resources, therefore competition (struggle for existence)
|
|
|
Term
| Darwin’s problems and questions: |
|
Definition
-What is the source of variation?
-What is the mechanism of heredity?
-How do new species actually form?
-Can we actually observe evolution happening?
|
|
|
Term
| Some Current Evolutionary Problems: |
|
Definition
1. Measuring the intensity of selection in the real world
2. Measuring the mutation rates and their importance
3. Rates and mode of evolutionary change (gradualism vs. “punctuated equilibrium”)
4. Effects of population size, structure (mating systems, etc.)
5. Symbiosis and co evolution
|
|
|
Term
| Evolution in Action (examples) |
|
Definition
- Industrial melanism (peppered moths)
- Possible origin of HIV:
- STLV-III in green Rhesus monkeys in Zaire (1970); humans not susceptible, but virus mutated to HTV-III and was first reported in humans in 1981. Arrived in US via Haiti: 14,000 cases reported by 1985. Estimated world HIV/AIDS (15-49 years) = 53.6 million (2007) (=0.8% pop)
|
|
|
Term
|
Definition
Bacteria resistance to antibiotics in:
lab cultures
people
Insects/Pests resistance to insecticides
takes 20+ sprayings on cotton crops
Malaria mosquito resistance to DDT
Wingless flies on windy islands and in lab
|
|
|
Term
|
Definition
| group of interbreeding individuals, reproductively isolated from other groups. |
|
|
Term
|
Definition
| the formation of new species; the splitting of evolutionary lineages |
|
|
Term
|
Definition
| evolutionary changes that “fit” organisms to their environment |
|
|
Term
| Speciation can occur in two ways: |
|
Definition
Linear Speciation and Branching Speciation |
|
|
Term
|
Definition
| changes in a single genetic lineage with time. A new species replaces an old species, e.g. Bison Antigua -- Bison bisons |
|
|
Term
|
Definition
original species evolves into two or more species, e.g.
original species --> original species
or new species A
original species --> new species
or new species B (adaptive radiation)
|
|
|
Term
|
Definition
necessary first-- e.g. barriers or breaks in the population via rivers, rifts, deserts, oceans, mountain ranges, etc.
Colonization of isolated habitats by part of the population (e.g. island, mountain top)
Gradual/continuous/clinal changes can take place first, followed by isolation, e.g. Rana pipiens f/Texas to USNE
|
|
|
Term
Isolating Mechanisms (besides Geographical)
Pre-mating mechanisms
|
|
Definition
- Temporal/Seasonal isolation (e.g. rainbows, spring; brown, fall spawning)
- Ecological/Habitat isolation (e.g. blue jay, city; stellar jay, pine forest)
- Behavioral isolation (e.g. yellow-headed and red-winged blackbirds vs. mating rituals; also different species of ducks)
- Mechanical isolation (e.g. spider and stonefly genitalia match)
|
|
|
Term
Isolating Mechanisms (besides Geographical) Post-mating Mechanisms: |
|
Definition
-Gamete incompatibility, e.g. mass spawning on coral reefs
-Zygote/ embryo incompetence
-Hybrids have reduced viability (mules)
-Hybrid sterility (ligar)
|
|
|
Term
|
Definition
| the science of naming organisms |
|
|
Term
|
Definition
| taxonomy plus evolutionary relationships and history of organisms |
|
|
Term
|
Definition
| an evolutionary history of a group of organisms, often pictured as a phylogenetic tree |
|
|
Term
|
Definition
-the sum of the kinds of organisms, including the genetic variability, complicated by the degree of their evolutionary (historical) and symbiotic (ecological) relationship
-the variety of life and its processes
-a progress report on the evolutionary processes
|
|
|
Term
Why study biodiversity? to... |
|
Definition
-understand evolutionary processes
-increase our appreciation of our surroundings
-relative evolution and ecology via the phenomenon of adaptation
-appreciate the importance of extinction
-provide evolutionary context of human species
|
|
|
Term
|
Definition
Generally= failure to adapt to environmental change Today:
Habitat Destruction:
Direct: rainforest clearance, wetlands filled in, etc.
Indirect: pollution, etc.
Competition: of native with exotic species: e.g., zebra mussel in N.A. or rabbits in Australia
Market hunting: and gathering for: food, fur, aquaria, zoos, drugs, pets, research, etc. e.g.: Dodo bird, passenger pigeon, North Atlantic manatee (Others: CO elk, cheetahs, elephant seals)
|
|
|
Term
|
Definition
Species as resources:
-ecological balance
-economic (food, fiber, Rx)
-genetic stocks
-recreational value
-esthetic value
-scientific study
|
|
|
Term
| How did Biodiversity get started? |
|
Definition
1. abiogenic formation of the simple organic molecules
2. polymerization→macromolecules
3. origin of micro spheres
4. origin of prokaryotic cells
|
|
|
Term
|
Definition
- 11 K Species Hydroids, Jellyfish, Sea Anemones, Corals |
|
|
Term
| Ecological Role of Cndiaria |
|
Definition
Jellyfishes: cosmopolitan; bad reputation with stinging cells
Sea Anemones: large polyps; solitary
Corals: small polyps; colonial; secrete CaCO3 base
Coral Reefs: -distribution: warm, clear waters
-Diversity of phyla: greatest
-Size: largest structures built by organisms
-Provide home and groceries for many species
|
|
|
Term
|
Definition
-18.5 K Species
Flatworms, Flukes, Tapeworms
|
|
|
Term
|
Definition
|
|
Term
|
Definition
100 K Species
Mostly marine, come fresh water; few terrestrial
Soft-bodied animals
|
|
|
Term
|
Definition
Chitons
Clams-bivalves
Snails-gastropods
Squids and octopuses
|
|
|
Term
|
Definition
Visceral mass (body)
Shell-for protection and support
Mantle-secretes the shell
Foot-for locomotion
Radula-for chewing/grazing/drilling
Gills-for gaseous exchange
|
|
|
Term
|
Definition
| 1 K species, all marine, 8 shell plates, graze on encrusting algae on rocky shores |
|
|
Term
|
Definition
- belly footed, 80 K species, snails, conchs, abalones, nudibranchs
- Spiral shells
- Mostly marine, some FW and terrestrial
- Herbivores and carnivores
- Highly variable in size, color, shape, some rare and expensive
- Sexes separate or combined (hermaphroditic)
- Some without shells; sea slugs and nudibranchs
|
|
|
Term
|
Definition
-hatched-footed, 15 K species, clams, mussels, oysters, scallops
- 2 hinged shells
- Filter feeders-suck in water and filter it through their gills
- Mostly sedentary, but also dig in sand and mud
- Some form protective nacre around foreign objects=pearls
- Size range to 4’+ shells and 600 pounds
|
|
|
Term
|
Definition
- octopuses, squids, cuttlefish, nantiluses: 800 species, head footed, all marine
-Are smartest, largest, fastest of all invertebrates
-Have 8 more arms with or without suction cups
-Have eyes as complex as our own
-Have a beak for dissecting prey
-Have an ink gland for distracting predators
-Have a siphon for jet propulsion
-Can easily change color and body texture to blend in
-ARE MOSTLY NOCTURNAL-all carnivores
-Are shy and non-aggressive toward people
-Examples of:
-Size: up to 60 ft. long and 800 pounds
-Speed: faster than a fish in short bursts
-Intelligence: smartest invertebrates
-Curious and gentle
|
|
|
Term
|
Definition
12 K species
Segmented worms- all habitats
|
|
|
Term
|
Definition
-Earthworms and their relatives
-Serial repetition of body parts=
Metamerism- evolutionary adaptation of such
-Have the same complex organs and organ systems of higher organisms
-Evolved a coelomic body cavity, just like ours; maximizes body movement and flexibility without compromising function of internal organs
-Three major groups:
Earthworms-terrestrial-soil builders
Polychaetes-marine
Leeches- freshwater-medicinal leech
|
|
|
Term
|
Definition
2 Million species
Joint-footed Animals-mostly terrestrial
|
|
|
Term
|
Definition
Joint-footed Animals-mostly terrestrial
-The most successful phylum in terms of number of species (diversity)
-Exoskeleton of chitin: -Protection from predators and from dessication; limitation to growth therefore molting; internal muscles provide for super-human strengths
-Heteronomous segmentation from the annelids; therefore large diversity of segments and functions of appendages
-Head, thorax, and abdomen of fusion of these areas
|
|
|
