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Flashcards in Life history Deck (30)
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1

life history

the adaptations of an organism that influence aspects of its biology, such as the number of offspring it produces, its survival, and its size/age at sexual maturity

2

Principle of allocation

if an organism allocates energy towards one function, such as growth/reproduction, it reduces the amount of energy it can spend on other things, like defense mechanisms

3

What do costly traits signify

a high quality individual

4

Coho salmon reproductive trade offs

redder salmon have easier access to fertilize eggs because red is hard to produce and it makes them look better.
less red salmon invest in faster sperm

5

David Lack's hypothesis

Selection favors clutch size with maximum surviving offspring. Accounts for trade offs b/t
-clutch size
-probability of individual survival
-how many survive

6

Why didn't Lack's hypothesis prove to be true?

1. maximum clutch sizes reduced future reproductive fitness in the mother
2. Maximum clutch sizes reduced (reproductive) fitness in offspring
3. an individual's maximum is not necessarily equal to that of the population

7

What experiment did lack do?

He added an extra egg to a clutch and it reduced both the mother's future reproductive fitness and that of the offspring

8

Kiwi trade off

Giant egg
few offspring
invested in heavily

9

European kestrals

trade off between survival and paternal care

10

plant investment in seed size

Few large seeds = bigger, taller, stronger seedlings with increased recruitment

Many small seeds = advantage in areas of high disturbance

11

r selection
(and example)

-high population growth rate (reproduce quickly)
-unpredictable environments
-better colonizers
-quickly harvest resources and reproduce, even if its inefficient
-e.g. tailless tenrec has 32 pups

12

K selection

-efficient resource use
-predictable environments
-better competitors
-slow growth and slow to reproductive maturity
-high investment in offspring to yield big size
-use resources efficiently --> good for scarce resources

13

Humpback whale

-loses 70% of blubber while feeding baby

14

3 key components to life history

1. How many offspring per reproductive episode?
2. How often does organism reproduce?
3. What is the age of sexual maturity?

15

semelparity vs iteoparity

semelparity = reproduce once then die (r selection)

iteoparity = reproduces multiple times (K selection)

16

chambered nautilus

only iteoparous cephalopod spawner

17

synchronous semelparity

cicadas that only come out once every 13 or 17 years
-all emerge, reproduce, and die in same year
-all individuals in population are the same age

18

Salmon as a spawner

semelparous
-leave for ocean as a small fry
-return to natal ground to reproduce
-invest in MANY gametes

19

Advantage of iteoparity

-Cole found that r was greater in iteoparous organisms whether 40 or 50 offspring were produced
-greatest value when survival of offspring is uncertain
-tend to be iteoparous when adult survivorship is high
-also, shorter pre-reproductive time increased r

20

Reznick and Endler's guppy experiment

-if predators focus on the young or there are no predators, then K selected syndrome
-if predators focus on adults, then r selected syndrome and faster reproduction

21

Pumpkinseed fish

when adult survival was lower than juvenile, there was greater body mass put towards gonads (GSI)

22

Opossums

-Mainland ones had higher predation, so their offspring aged and reproduced at quicker rates than the island ones

23

snakes + lizards

higher survival rate lead to later maturity

24

Lions

-males are evicted at 2 yrs old to go take over another pride
-females are therefore sexually mature by age 2

25

Prime reproductive age

stags are the ones with the prime reproductive age as opposed to the female hinds

26

Types of parental care

1. none
2. uni-parent
3. bi-parent

27

No parental care

sea turtles, megapodes, praying mantis

28

uni parent care

seahorses (male), seals, spiders, humpbacks

29

bi-parental care

dung beetles, titi monkeys, birds

30

Grimes Triangle

1. Ruderals (high disturbed habitat)
-grow fast, makes seeds quick, r-select

2.Stress-tollerant (high stress, no disturbance)
-grow fast, K select

3. competitice (low disturbance, low stress)
-grow well, but eventually compete for resources