, ·
the
~energetic
production of a new
gen of
orgs from an
existing gen
->
ensures the continued survival of the species
goal of each species
I
to produce the max .
no .
of
Surviving offspring While using the least amount of energy/ reproductive effort
·
a sexual repro- in lower +
Microscopic animals -
energy efficient :
low reproductive effort
↳
only involves a single animal
sexual repro in all vertebrates more complex- high reproductive effort
·
-
=
↳ led to development of strategies to maximise reproductive success in diff . environs
↳ enables species to breed successfully +
survive to reproductive age
A s t ea
regists
few offspring
·
produce only a -
high level of parental care =
larger no .
of
offspring survive to adulthood
·
typical climax species
than environmental hold=
↳ produce only slightly more offspring max pop .
density close to
carrying capacity
·
eg
:
elephants -
long lived :
life
expectancy
=
10
yrs
↳
only start
mating at 20
yus
↳
have I
baby at a time =
3
yrs apart
↳ whole group looks after offspring
=
protects them till adulthood
↳
ensures most survive
m stea
regingts
·
reproductive effort expended on
producing large numbers of eggs
- minimal/no parental care
=
very few offspring survive into adulthood
turtles life expectancy 50-100
yus
eg
=
· : :
at produce lots of eggs when
longer needed for growth
↳
sexually mature
Kyrs- use
energy to
energy no
↳lay 90-130 egg every 2-5
yrs
↳very low survivorship = 2-101 , 000 reach adulthood
(birds fish in seal
↳ due to predation of
eggs (ants+ birds) and hatchlings + crabs ; Octopus +
large
turtles predated
↳
predation pressure decreases wI
increasing size larger by sharks
=
↳
r-strategy ensures continued survival despite high predation
s avea i r strip reve re s
* K-Strategy
become adult
most offspring
·
·
mortality occurs
mainly among older individuals
r-Strategy a
become adult
few offspring
·
·
high mortality rate when young
·
once established =
improved
life expectancy · birds and Plants
mortality decreases steadily wi time
·
old
young org just as
likely to die as
org
·