honors biology: populations

Fig. 53-4a

(a) Clumped

Fig. 53-4b

(b) Uniform

Fig. 53-4c

(c) Random

Concept Check

• One Species of forest bird is highly territorial, while a second lives in flocks. What is each species’ likely pattern of dispersion? Explain

Fig. 53-3

Births

Births and immigrationadd individuals toa population.

Immigration

Deaths and emigrationremove individualsfrom a population.

Deaths

Emigration

Concept Check

• Each female of a particular fish species produces millions of eggs per year. What is the likely survivorship pattern? Explain.

Semelparity or Iteroparity

Concept Check

• Consider two rivers. One is spring fed and is constant in water volume and temperature year-round; the other drains a desert landscape and floods and dries out as unpredictable intervals. Which is more likely to support many species of iteroparous animals? Why?

Evolution and Life History Diversity

• Life histories are very diverse• Species that exhibit semelparity, or big-bang

reproduction, reproduce once and die• Species that exhibit iteroparity, or repeated

reproduction, produce offspring repeatedly• Highly variable or unpredictable environments likely favor

big-bang reproduction, while dependable environments may favor repeated reproduction

Resource Partioning

Concept Check

• Where is exponential growth by a plant population more likely – one a newly formed volcanic island or in a mature, undisturbed rain forest? Why?

Fig. 53-13b

Nu

mb

er

of Daphnia

/50

mL

0

30

60

90

180

150

120

0 20 40 60 80 100 120 140 160

Time (days)

(b) A Daphnia population in the lab

Concept Check

• Indentify three density-dependent factors that limit population size, and explain how each exerts negative feedback.

Metapopulaiton

Fig. 53-22

8000B.C.E.

4000B.C.E.

3000B.C.E.

2000B.C.E.

1000B.C.E.

0 1000C.E.

2000C.E.

0

1

2

3

4

5

6

The Plague

Hu

man

po

pu

lati

on

(b

illio

ns)

7

Fig. 53-23

2005

Projecteddata

An

nu

al p

erc

ent

incr

ease

Year

1950 1975 2000 2025 2050

2.2

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

Fig. 53-24

1750 1800 1900 1950 2000 2050

Year

1850

Sweden MexicoBirth rate Birth rate

Death rateDeath rate0

10

20

30

40

50B

irth

or

dea

th r

ate

per

1,0

00 p

eop

le

Concept Check

• During the demographic transition from high birth and death rates to low birth and death rates, countries usually undergo rapid population growth. Explain why.

Fig. 53-25

Rapid growthAfghanistan

Male Female Age AgeMale Female

Slow growthUnited States

Male Female

No growthItaly

85+80–8475–7970–74

60–6465–69

55–5950–5445–4940–4435–3930–3425–2920–2415–19

0–45–9

10–14

85+80–8475–7970–74

60–6465–69

55–5950–5445–4940–4435–3930–3425–2920–2415–19

0–45–9

10–14

10  10 8 866 4 422 0Percent of population Percent of population Percent of population

66 4 422 08 8 66 4 422 08 8

Fig. 53-27

Log (g carbon/year)

13.49.85.8

Not analyzed