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BSCI106 > Final emphasis > Flashcards

Final emphasis Flashcards

(54 cards)

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1
Q

Bioaccumulation

A

over time the contaminant levels rise in the organism

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2
Q

Biomagnification

A

Contaminant levels increase as the size of the animal increases

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3
Q

BPA (Bisphenol A) is a chemical that acts like a hormone in humans. Women exposed to high levels of BPA early in their pregnancy had an 83 percent greater risk of miscarriage than women with lowest levels.

A

Exposure is from

  • linings on some kinds of canned food
  • some kinds of water bottles
  • paper receipts
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4
Q

Behavior cannot be determined by genes because it has no physical basis: TRUE OR FALSE

A

FALSE

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5
Q

Selfish

A

the actor benefits at the expense of the recipient

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6
Q

Cooperation

A

both participants benefit

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7
Q

Spiteful

A

Both participants are harmed

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8
Q

Altruistic

A

actor is harmed (or at risk), recipient benefits

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9
Q

Explaining altruism

A

“Good of the species” -group selection doesn’t work in most cases

  • Inclusive fitness and Kin Selection
  • Reciprocal alruism
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10
Q

Inclusive Fitness

A

J.B.S Haldane- 1930s
- I would gladly give up my life for two siblings, or 8 first cousins
-Personal “sacrifice” may be offset if the recipient is related
-One can reproduce one’s genes by
: producing offspring- direct fitness
: helping related individuals produce offspring- indirect fitness

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11
Q

Inclusive fitness (cont.)

A 
Relatedness (r) 
Probability that alleles in two individuals are identical by descent
-parent/offspring r=1/2
Siblings  r=1/2
First cousins r=1/8
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12
Q

Hamilton’s rule

A

a gene for altruistic behavior is likely to spread if Br > C
-B= Benefit to the recipient. A large B means that the related individual benefits a lot
-r = Relatedness. A large r means that the benefit goes to a closely-related individual
-C = cost to actor. A small C means little cost
Imagine a clone (r=1)

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13
Q

Kin Selection

A

Ground Squirrels

  • similar to example in test
  • live in colonies
  • individuals produce alarm calls to warm other colony members of predators
  • Female member of the colony are relatives
  • Females are much more likely to give alarm calls than are males
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14
Q

Eusociality

A

Complex social systems with the following three characteristics

  • overlap between parent/ offspring generations
  • cooperative care of young
  • Specialized non-reproductive castes
    ex. hymenoptera- many bees , ants, wasps
  • Naked mole rats
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15
Q

Naked mole rats and Bees

A

Live in colonies

  • all the offspring produced by one queen
  • Queens shove and intimidate other colony members
  • potential female rivals bullies to the point that they can’t ovulate
  • Especially distant relatives
  • A very high degree of inbreeding (high r among colony members: 0.8)
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16
Q

white-fronted bee eaters

A

Live in “clans” of variously related individuals

  • young adults will help their clan-mates raise more offspring
  • deliver food, help build nest, etc.
  • Territories scarce, so tough to reproduce on their own
  • The closer the relationship to the offspring, the greater the likelihood they will help
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17
Q

Men with elevated testosterone levels show more affiliative behaviors during interactions with women

A

Testosterone is thought to play a key role in male-male competition and courtship in many vertebrates, but its precise effects are unclear.
-The sex of the stimulus person did not affect the participants’ behavior overall. however, in interactions with women, those men who had experienced a greater T increase during the contest subsequently showed more interest in the women, engaged in more self-presentation, smiled more and made more eye contact

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18
Q

Reciprocal Altruism

A

Altruistic acts can occur even between individuals that are not related.
-benefits to recipient must outweigh cost to actor
-cheaters (those that fail to reciprocate) must be punished somehow
: Facilitated by
-stable groups- likely to see the same individual again
-repeated opportunities for altruistic acts
-Individuals having the capacity to remember
-potential altruists interact in a symmetrical way (i.e. neither one is expected to generally be the giver or the receiver)

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19
Q

Blood sharing vampire bats

A

feed on blood of large mammals - a difficult food source
-regurgitate food for other bats that have been unable to get blood
: usually to closely related individuals

Benefit to recipient > than cost to donor
-a given amount of blood is worth more to a starving bat than a full bat

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20
Q

Social behavior and humans

A

many human behaviors are readily explainable in terms of direct or indirect fitness
- parental care
-Clannishness (family values)
-incest avoidance
: or reciprocation
-humans are social, and we never forget a debt
-are feelings of gratitude, trust, shame, guilt, responsibility simply a result of evolution based on systems of reciprocal altruism?

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21
Q

A Darwinian view of disease

A

History matters- Disease and infirmity in an evolutionary context. Some infirmities that seem very maladaptive reflect the effects of history

  • The Red Queen - evolving pathogens and their environment
  • The evolution of virulence
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22
Q

Myopia

Study These Flashcards
A

Myopia is very common

  • has a negative effect
  • has a heritable component

-few adults over 35 had attended formal school in Barrow Alaska
they did not strain their eyes as much etc.

23
Q

History

Study These Flashcards
A

there were some reasons why certain diseases were around such as sickle-cell anemia
Additionally, the disease sets after reproducing so the genes continue

24
Q

The Red Queen Evolving Pathogens

Study These Flashcards
A

Antibiotic resistance in bacteria:
-bacteria evolve quickly
: short generation time, lots of genetic exchange
-Widespread use of antibiotics selects for resistant strains
-Bacterial evolution by natural selection can take the “wonder” out of overused “wonder Drugs”

25
Virulence
Deaths per infection -Virulent diseases will eventually evolve towards reduced virulence and benign coexistance
26
Pathogens
Must do two things: Reproduce -often causes sickness in the host -higher rates of reproduction do more damage to the host 2) Disperse to new hosts -this may or may not depend on the condition of the host
27
Rhinovirus
The common cold - relies on host mobility for transmission -infects only those areas that promote transmission : coughing and sneezing are not by-products of an infection- they are the virus' way of using us to transmit their genes
28
Animal vectors
carry pathogens from host to host - mobility of host is not necessary (in fact, immobile hosts may be less able to fend off mosquitoes) - Transmission is pretty effective, so even the long-term survival of the host is not very important - pathogens reproduce in many tissues to increase chance of being picked up by vector
29
Cultural vectors
Causes severe diarrhea and death -virulence of cholera strains vary in virulence -contamination of drinking water favors virulence : reduces cost of immobilizing or killing host :feces in water provide an efficient and indirect transmission route
30
New world meets old world
Apparently two major causes. Relative to the New world - a long history of animal domestication :domesticated animals are the source or a reservoir for many human diseases -A long history of large, dense populations : large and/or dense populations allow pathogens to persist in the population -maintains a reservoir of diseases -maintains selection for disease resistance
31
Uses
- Consumptive uses (non-market) - Productive uses (market valuation) - Amenity value - Educational and scientific value - Existence value- the value we derive from knowing that a species exists - Intrinsic value- do other species have an intrinsic right to survive?
32
Causes of biodiversity loss
- Land use change - Habitat fragmentation - etc.
33
Declining biodiversity
current extinction rate estimation relies on: -Species- area relationships -Changes in the threat status of species (ex. shift from endangered to critically endangered). -Rates of population decline or range contraction of common species - Rates of biodiversity loss are accelerating, but humans have always had a large impact on other species. : bones found of pacific islands reveal the prehistoric extinction of up to 8,000 species of birds following colonization by Polynesians : most of the species were endemic :some of the extinctions involved entire guilds
34
Threats of biodiversity
``` the primary threats: -habitat loss and degradation -invasive species - overexploitation : for any given species, multiple factors are likely to contribute to decline and extinction ```
35
Overexploitation
Overfishing in the oceans has lead to declines in top predators, and other species. : for every ton of fish caught by commercial trawlers, 1 to 4 tons of other marine life may be brought aboard, called bycatch
36
Threats to Biodiversity: Invasive species
Greatest "losers" among native species tend to be specialists with adaptations that resulted from evolution in a particular place and context -The "winners" tend to be generalists with less stringent habitat requirements
37
A flagship species
Public interest to garner support for conservation | -A charismatic organism that people will want to protect
38
Umbrella species
shield other species with similar habitat requirements
39
Oysters could help clean up the Chesapeake Bay
A reef in MD seeded with oysters - about 130 square meters- removed 20 times more nitrogen pollution in one year than a nearby site that had not been seeded.
40
Temperature sex determination
eggs in warm nests are likely to hatch as females, while males hatch in cooler nests
41
Permian extinction
Most severe biotic crisis in the fossil record. Its occurrence has been attributed to increased CO2 levels deriving from massive Siberian volcanism - We propose that the disruption of the carbon cycle resulted from the emergence of a new micorbial metbolic pathway that enabled efficient conversion of marine organic carbon to methane - the methanogenic expansion was catalyzed by nickel associated with the volcanic event
42
Mass extinctions
``` multiple causes: marine regression glacitation asteroids volcanic eruptions microbial evolution : some type of climate change probably always implicated. ```
43
American Pleistocene Extinctions
135 species (about 36 of 45 genera) of large mammals went extinct in N. and S. America about 11,000 years ago - climate change - Human mediated
44
Activities of modern humans that threaten biodiversity by causing extinctions
- overexploitation -introduced species : predators (commensalism) : competitors (cattle, carp, plants) : Diseases (bird pox, malaria) -domino extinctions (mutualists, parasites) -Habitat destruction -Global climate change -Warfare (conventional and nuclear)
45
Aging
Progressive loss of function with age - decreasing fertility rates - increasing mortality rates
46
What if we didn't age?
Individuals surviving to reproductive age represent successful genes and gene combinations (at least in the current environment) -immortality could be a means of maximizing individual fitness
47
Why does aging occur: | Hypothesis 1
Wear and tear: an inevitable outcome of living :organisms wear out
48
Why does aging occur: | Hypothesis 2
Turnover: Programmed death to remove older generation -clear out yesterday's model to allow room for new, and possibly more successful, offspring
49
Why does aging occur- | Hypothesis 3
Mutation-accumulation: Genes that exert deleterious effects only very late in life are protected from natural selection -mutations don't show up until after reproduction - late-acting deleterious mutations will accumulate in a wide variety of systems, and will evolve as neutral genes - at advanced age, these various deleterious mutations will kick in, leading to general system failure ( also likely)
50
Huntington's Disease
caused by a dominant allele | -usually strikes after reproduction has already occurred
51
Why does aging occur: | Hypothesis 4
Antagonistic pleiotropy: genes can have multiple effects (pleiotropy) -some genes will promote early survival/ reproduction at the expense of longevity -neutering promotes a longer (if not necessarily more fulflling life). Neutered cats and dogs live three years longer, on average. Likely (natural selection may favor genes with late-acting deleterious effects but beneficial early effects on reproduction)
52
The Common message
The mutation accumulation and antagonistic pleiotropy theories both imply that aging rates are influenced by natural selection - depends on risk of death due to other factors - organisms with high extrinsic mortality rates should favor early reproduction over longevity - organisms with low extrinsic mortality rates should favor longevity more
53
comparative evidence
correlation between protection form predation and low aging rates
54
Mutation accumulation
late-acting deleterious mutations do not experience strong selection : reproduction is over, and the organism is likely to have already died from other causes

BSCI106 (3 decks)

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