Exam 3 Flashcards
Gregor Mendel
discovered the mechanism for inheritance using pea plants
What was convenient about Mendel’s experiment that led to straight forward results
He used traits that were not sex linked (close together on the same chromosome)
the bigger the chromosomes
the more genes it has
Hardy-Weinberg Law
p^2+2pq+q^2=1
the probability of homozygosity (AA) dominant
p^2
the probability of heterozygosity
2pq
the probability of homozygous (aa) recessive
q^2
Hardy Weinberg Assumptions
mating is random
mutations do not occur
no gene flow (pop is closed)
population is large
no natural selection
diploid population
homozygosity increases with
inbreeding (the more closely related, the more likely to be homozygous)
genes move toward
fixation
effective population size
The size of an ideal population subject to the same degree of genetic drift as a particular real population
The effective population size equals the number of adults contributing gametes to the next generation
NE=
4NmNf/Nm+Nf
Population bottleneck
A genetic bottleneck occurs when a population is greatly reduced in size. The bottleneck limits the genetic diversity of the species because only a small part of the original population survives. With a greatly reduced gene pool, the remaining members of the species may have trouble adapting to new environmental conditions, such as climate change. A genetic bottleneck can be caused by a number of factors, including natural disasters, overhunting, or habitat destruction.
a founder population of 10 may hold
90% of the genetic diversity found in the parent population
founder effect
The founder effect is the reduction in genetic variation that results when a small subset of a large population is used to establish a new colony.
History of the founding event
severe winter 1983-84, pronghorn from North Park, Colorado, became permanent residents in Middle Park, Colorado
what did pronghorn have to do to reestablish itself in Middle Park
pronghorn passed through a canyon which traverse unsuitable habitat
what increases reproductive success
altruism- raising someone else’s young
inclusive fitness
if the genetic ties within a generation are closer than the ties between a generation, each member of the generation might be motivated to invest in a parents reproductive success rather than his or her own
William Hamilton
came up with inclusive fitness through a study of the Hymenoptera, social ants, bees, and wasps
Bartz’s hypothesis
begins with mating of a male and female who are unrelated but are each the products of intense inbreeding, the product of this union are essentially identical and therefore more related to one another than to their parents
how does genetic asymmetry increase inclusive fitness
it encourages helping behavior in both sexes because each sibling can increase its inclusive fitness by assisting in the creation of brothers and sisters (going back to inbreeding, more pure lines)
Eusociality precondition
parental care in a protected nest, where offspring are defended against predators and provided with food, dispersal is too costly and there is an incentive to be a helper to say in a protected nest
coevolution
occurs when interactions between species over time lead to reciprocal adaption
endoparasite
lives within the host
ectoparasite
lives outside on the host
microparasites
viruses
bacteria
protozoans
macroparasites
lice, fleas, ticks, mites, and parasitic worms
epizootic
rapid spread and bacterial diseases in dense populations in animals
epidemic
rapid spread and bacterial diseases in dense populations in humans
epidemic plague
plague has killed more people and has had a greater effect on human history than any other zoonotic disease
best documented plague vectors
female oriental rat fleas (Xenopsylla cheopis)
what does female oriental rat fleas transmit
bacteria as they feed on an infected animal, often black or brown rats
brown rat name
R. norvegicus
black rat name
Rattus rattus
examples of ectoparasites
streblid bat flies, short-tailed fruit bat, copepods and isopods on balloon fish, bed bugs
definitive host
the one in which the parasite becomes an adult and reaches maturity
intermediate hosts
harbor some developmental phase
what has led to the proliferation of parasitic flat worms
migration, intense finishing, and planting larger and larger tracts of land
Zombie ants
when the fungus infects a carpenter ant, it grows through the insect’s body, draining it of nutrients and hijacking its mind
over the course of a week, it compels the ant to leave the safety of its nest and ascend a nearby stem
it stops the ant at a height of 25cm, a zone with precisely the right temperature and humidity for the fungus to grow. it forces the ant to permanently lock its mandibles around a leaf
eventually, it sends a long stalk through the ant’s head, growing into a bulbous capsule full of spores. And because the ant typically claims a leaf that overhands its colony’s foraging trails, the fungal spores rain down onto its sisters below, zombifying them in turn
Sexual parasite in fish
The male fish (angler fish) does not have a working digestive system and needs to utilize that of a females. When a male finds a female, he uses his teeth and attaches himself to her. He realizes an enzyme that fuses the tissue of the two together. This gives males direct access to female’s digestive system for nutrients and circulatory system for gas exchange. In return he gives the female sperm, but he is competing with other males that are living on that same female.
kleptoparasitism
a form of social parasitism in which the parasites obtain a substantial portion of their food by stealing it from the host (bald eagles steal fish from osprey)
social parasitism (brood parasitism)
occurs when an invading reproducer uses the workers of a nest she did not construct to rear her reproductive offspring
plant parasites
squawroot is a holoparasite on the roots of oak
holoparasite
plants that are not capable of photosynthesis and obtain all nutrients and water from a host plant
plant response to parasitic eggs
Galls: plants produce galls to exposes the larvae of gall insects to predation. The woodpecker eats larvae off the goldenrod stem.
hemiparasites
photosynthetic, but they draw water and nutrients from their host plant
mistletoe
sticky seeds attach to limbs and send out roots that embrace the limb and send roots into the sapwood
two examples of hemiparasites
mistletoe and Indian paint brush
commensalism
one species benefits and the other is unharmed
examples of commensalism
whale barnacles and whales: attaching to the whales gives the barnacles a stable place to live, a free ride, and access to plenty of food
epiphytes and trees: Epiphytes grow on sides of tall trees in an attempt to be closer to the sunlight
Non-obligate mutualism (getting help with parasites)
one species helps another with removing a parasite, while also gaining a benefit
-Oxpeckers and black rhino: eat parasites on the rhino
-cleaner goby: they will remove parasites from neighboring fish
Nonobligatory (facultative) mutualism
A type of mutualism in which the interacting species derive benefit from each other but not being fully dependent that each cannot survive without the symbiotic partner.
facultative mutualism are widely involved in
seed dispersal and pollination, the benefits are spread over plants by guilds of insects
pollinators (nonspecific)
spread pollen and increase chances of reproduction of plants
many different insects can pollinate many different flowers or plants)
seed dispersal
plants form partnerships with snails
Clarks Nutcracker
disperses the seeds of pines
agouti
the only animal that can open the Brazil nut
obligate mutualism
are permanent and both partners must form the relationship in order to survive (algae and fungi=lichen)
a specific pollinator
yucca and yucca moth have formed an obligate mutualistic relationship
adult moth provides pollen only to the yucca
yucca provides food in the form of seeds for caterpillar
cat only eats some of the seeds
What relationship exists between clownfish and anemones
give and take
clownfish and anemones
clownfish because of bright colors attracts prey for the sea anemone to hunt and feed on. The clownfish gets the scraps and leftovers
clownfish eats up dead tentacles of polyp and the algae that settles on it
better water circulation for sea anemone when clownfish swims through it
anemone feeds on clownfish feces
clownfish chases away polyp eating fish
polyp provides protection to fish with tentacles that are venomous to other fish
In which polyps are zooxanthellae found
cnidaria and scleractinian coral
what do zooxantheallae do for coral polyps
they translocate products of photosynthesis to the host and in turn they receive inorganic nutrients (co2 and Nh4+)
ants and treehoppers or aphids
aphids produce a sugary waste that attracts ants, the ants in return protect the insects from predation
ants and bullhorn acacia
ants protect the bullhorn Acadia from insects and rodents
the bullhorn thorns provide home for larvae and eggs, tree also provides nectar for ants
third member mutualistic relationship
ectomycorrhizae need the tree for energy
tree needs the ectomycorrhizae for uptake of nutrients from the soil
small mammals are needed to disperse the spores after feeding on the truffles
R selected
produce many young and invest little energy (parental care) in the young
these species reach sexual maturity early in life
these are short lived species
K selected
have one or two young, lots of parental care, species reach sexual maturity late in life, long lived species
humans have never found a way to sustainably harvest
K selected species
Whales
1860 the blue whale became the most commercially important species
catches in antarctic peaked in 1931 at 30,000 animals. However, the catch declined to 2000 in 1963 (about the time the US stopped whaling)
Alaskan King Crab
overfishing in Alaska has caused the Alaskan King Crab and halibut to become commercially extinct
K species examples
Alaskan king crab and whales
landings of Cod and Haddock
Note the increase in fishing intensity for both species in 1960 through 1980 followed by rapid decline.
Up to certain point, stock can replace itself
Beyond this critical point, certain changes point to impending disaster.
keystone species
Every ecosystem has certain species that are critical to the survival of the other species in the system. The keystone species could be a huge predator or an unassuming plant, but without them the ecosystem may not survive.
Effect of removal of keystone
the elimination or depletion of one species can cause a chain reaction and deplete many other species, this effect is especially true if the species that is harvested is a KS.
keystone chain
Sea otters are the keystone species.
Whales put pressure on otters after having a limited access to prey. The otter population decreases to extremely low levels. The otters keep the sea urchin population in check which prevents the sea urchins from eating up the kelp forest.
Without otters, sea urchins will reproduce out of control and will eat up the kelp until it is gone.
economics of biodiversity
can we use species in a sustainable way?
Taxus Baccata
has medicinal purposes
freezes or disintegrated microtubules and prevents cancer cells from dividing
buffalo
there are no pure buffalo left, only hybrids, they are protected and provided with a habitat
they are used in foods at lower levels
collecting and recreating their habitat
turkeys
were collected and placed into empty habitats
one plant supermarket
winged bean- entire plant is edible, legume
rosy periwinkle
Madagascar plant that is the source of two alkaloid chemicals with powerful anti cavity activity (restores soil fertility)
largest living rodent
hydrochaeridae capybara- are food sources for predators but their habitat must be maintained for them to live there
invasive species
is an introduced organism that becomes overpopulated and harms its new environment (takes over and disrupts the ecosystem)
Spotted knapweed centaura stoebe Ssp
It displaces native vegetation and reduces the forage potential for wildlife and livestock.
kudzu
grows in disturbed areas
covers habitat in the SE US
fire ant
invasive, spread to south eastern and western US
Formosan subterranean termite
introduced in Louisiana
competes with native species, causes structural damage to buildings
invasive species
zebra mussels
kudzu
formosan termite
fire ant
cactus moth
pigs
Burmese pythons
threats to endangered species
habitat degradation/loss
invasive species
pollution
overexploitation
disease
