animal distribution is directly related with the environmental changes. These changes affect the over all life cycle of the animal. This further leads to adaptation in the organisum

1. The Biosphere and Animal Distribution
By
Mr. Nirbhay Sudhir Pimple
Department of Zoology
Abasaheb Garware College
Karve road. Pune-4.

2. Water has physical properties critical to life on earth.
The steady supply of sunlight maintains a suitable range of
temperatures for life metabolism.
Living matter requires a supply of major and minor elements
available on earth.
The earth’s gravity is strong enough to hold an extensive
gaseous atmosphere.

3. The environment is modified by organisms.
Organisms are adapted by evolution to the environment.
The earth is an open system with a continuous supply of
energy.
Building materials for life come from producers and are
cycled through consumers.
Life is part of a cycle of life-death-decay-recycling.

4. The primitive earth of 4.5 billion
years ago had a reducing
atmosphere of ammonia,
methane, and water and was fit
for pre-biotic synthesis of early
living forms.
This early atmosphere would be
fatal to today’s organisms.
The appearance of free oxygen in
the atmosphere is an example of
the reciprocity of life and the
earth.
Living organisms produce
changes in their environment and
must adapt and evolve.

5. The biosphere is the
thin outer layer of
the earth capable of
supporting life.
Includes living
organisms as well as
the physical
environments.

6. Biosphere - Subdivisions
 Lithosphere – rocky material of the earth’s outer shell.
 Source of mineral elements required for life
 Hydrosphere – water on or near the earth’s surface.
 Atmosphere – the gaseous component of the biosphere.
 Atmospheric oxygen is produced by photosynthesis.

7. Greenhouse Effect
Materials in the atmosphere,
such as CO2 and water vapor
retain heat, raising
atmospheric temperature.
Greenhouse effect
Burning fossil fuels
increases CO2 in the
atmosphere.

8. Greenhouse Effect
The greenhouse effect
provides conditions
essential for life on
Earth.
Humans are
increasing this
effect.
Increased
temperatures could
lead to a rise in sea
level as polar ice
melts.

9. Biomes
Varying combinations of both biotic and
abiotic factors determine the nature of Earth’s
many biomes.
Biomes are the major types of ecological
associations that occupy broad geographic
regions of land or water.
Each biome grades into the next – without
sharp boundaries.
Boundary areas are called ecoclines.

10. Terrestrial Biomes
Climate is particularly
important in
determining why
particular terrestrial
biomes are found in
certain areas.
Temperature
Rainfall
Solar radiation

11. Terrestrial Biomes
The sun’s rays strike
higher latitudes at a
lower angle.
Atmospheric heating is
less.

12. Terrestrial Biomes
Air warmed at the equator rises and moves
toward the poles.
Replaced by cold air moving away from the
poles.
Rotation of the earth complicates this pattern.
Three latitudinal cells result.

13. Terrestrial Biomes
Hot, moist air rises at
equator, cools, condenses
and provides rainfall
(tropical forests).
Warm air flows
northward, and sinks at
20-30° latitude – dry.
Air heats, absorbs
moisture (desert areas),
then the air flows toward
the equator again.

14. The Distribution of Major Terrestrial Biomes

15. General Features of Terrestrial Biomes
Vertical stratification
is an important
feature of terrestrial
biomes.
Canopy
Low-tree
Shrub understory
Ground layer
Forest floor (litter
layer)

16. Temperate Deciduous Forest
Temperate deciduous forests receive rain year-
round.
Cold winters and hot, humid summers.
Animals may migrate, hibernate, or survive on scarce
available food or stored fat through the winter.

17. Coniferous Forest
Coniferous forests, or taiga, are common in the
northern hemisphere.
Evergreens dominant
Colder, less rain than temperate forests.

18. Coniferous Forest
Mammals that
inhabit coniferous
forests include deer,
moose, elk, snowshoe
hares, wolves, foxes,
lynxes, weasels, bears.
Adapted for long,
snowy winters.

19. Tropical Forest
Tropical rain forests receive lots of rain and are
generally warm year-round.
Stratified
Diverse

20. Tropical Forest
Canopy – insectivorous birds and bats fly above
the canopy.
Fruit bats, canopy birds, and mammals live in the
canopy eating leaves & fruit.
Middle zones are home to arboreal mammals
(monkeys, sloths), birds, bats, insects,
amphibians.
Climbing animals move along the tree trunks feeding
at all levels.
Ground level contains larger mammals (capybara,
paca, agouti, pigs) as well as a variety of reptiles
and amphibians.

21. Tropical Forest
Nutrients in a tropical forest are tied up in living
organisms.
Soil is poor.
Slash and burn agriculture involves removing
vegetation to grow crops – but the soil is so poor that
the fields must be moved often.

22. Grassland
Temperate grasslands receive seasonal
precipitation and have cold winters and hot
summers.
Prairie

23. Grassland
Grasses and herds of
large grazing
mammals are
dominant.
Jackrabbits, prairie
dogs, and ground
squirrels are common.
Predators include
coyotes, cougars,
bobcats, raptors,
badgers, and ferrets.

24. Grassland
Savannas are tropical grasslands with seasonal
rainfall.

25. Grassland
Chaparral receives highly seasonal rainfall.
Shrubs and small trees are common.
Adaptations to fire.

26. Tundra
Tundra has a permanently frozen layer of soil
called permafrost that prevents water
infiltration.
Very cold, short growing season.
Little rain

27. Tundra
Tundra is often covered with bogs, marshes, or
ponds.
Grasses, sedges, and lichens may be common.
Lemmings, caribou, musk-oxen, arctic foxes,
arctic hares, ptarmigans and other migratory
birds.

28. Desert
Deserts have very low precipitation – less than 30
cm/yr.
Variable temperatures.
Animals often nocturnal and live in burrows.
Reptiles and small mammals are common.

29. Aquatic Biomes

30. Aquatic Biomes
Aquatic biomes account for the
largest part of the biosphere in terms
of area.
Can contain fresh or salt water.
Oceans cover about 75% of Earth’s
surface.
Have an enormous impact on the
biosphere.

31. Inland Waters
Only about 2.5% of the earth’s water is
fresh.
Much of that is found in polar ice caps or
underground aquifers.

32. Inland Waters
Lotic, or running water habitats include streams and
rivers.
More oxygen
Lentic, or standing water habitats include lakes and
ponds.
Less oxygen

33. Inland Waters
Oligotrophic
lakes – nutrient
poor & oxygen
rich.
Eutrophic lakes –
nutrient rich &
sometimes oxygen
poor.
Eutrophication
An oligotrophic lake A eutrophic lake
LAKES

34. Inland Waters
Streams and
rivers have a
current.
STREAMS AND RIVERS

35. Inland Waters
Animals living in vegetation or debris of
the bottom (benthos) are called benthic.
Snails, mussels, crustaceans, insects.
Animals up in the water column are
pelagic
Swimming animals are called nekton.
Floating or weak swimmers are called
plankton.

36. Wetlands
Wetlands
include areas
that are able to
support aquatic
plants.
May be
freshwater or
marine.
WETLANDS

37. Estuaries
Estuaries are
transition areas
between river and
sea.
Salinity varies from
nearly fresh to the
salinity of seawater.
ESTUARIES

38. Aquatic Biomes
Many aquatic biomes are stratified into zones or
layers defined by light penetration, temperature,
and depth.
The photic zone is the most productive.

39. Rocky Intertidal Zone
The rocky intertidal zone is alternately
submerged and exposed by the tides.
Upper zones are exposed to air longer.
Physical stress (desiccation, waves, temp,
salinity), predation, and competition produce
distinct bands.

40. Rocky Subtidal Zone
Kelp forests
dominated by
brown seaweeds
occupy shallow
subtidal waters.
Grazing urchins
and molluscs are
common.
Predators include
sea stars, fishes,
and otters.

41. Rocky Subtidal Zone
Coral reefs are
limited to the
photic zone in
tropical marine
environments
with high water
clarity.
Highly diverse
CORAL REEFS

42. Nearshore Soft Sediments
Intertidal and subtidal environments
with soft sediments include beaches,
mudflats, salt marshes, sea-grass
beds, and mangrove communities.

43. Nearshore Soft Sediments
Salt marsh habitat
includes grasses,
mussels, crabs, shrimp,
and polychaetes.
Burrowing organisms.
Deposit or filter
feeders.
Small fishes and birds
that feed on them are
common.

44. Nearshore Soft Sediments
Calm, tropical, coastal
areas support mangrove
communities.
Mangrove trees grow
submerged in soft
sediments.
Rich community of
detritus feeders (oysters,
crabs, shrimp).
Many fishes – often used
as a nursery ground.

45. Deep-Sea Sediments
The deep sea includes the continental
slope, continental rise, and abyssal plain.
Sand where there are currents, fine
mud where currents are weak.
Suspension feeding invertebrates are
common.
Deposit feeders found in muddy areas.

46. Hydrothermal Vents
Hydrothermal vents occur on the abyssal plain in
areas of submarine volcanic activity.
Archaebacteria that derive energy by oxidizing sulfides
form the basis of the food chain.
Grazed by bivalves, limpets, and crabs.
Other organisms, like tube worms, have symbiotic
archaebacteria.

47. Pelagic Realm
The pelagic realm includes the open
ocean area.
High oxygen, low nutrient levels.
Areas of upwelling bring nutrients up
from the sea floor.
OCEANIC PELAGIC BIOME

48. Pelagic Realm
Epipelagic – surface
waters
Mesopelagic – twilight
zone, supports a varied
community of animals.
Deep sea forms depend
on a rain of organic
debris from above.

49. Zoogeography
Zoogeography describes patterns of
animal distribution and species
diversity.
Why species and species diversity
are distributed as they are.

50. ZoogeographyThe history of an animal species must be
documented before we can understand why it
lives where it does.
Camels originated in North America and spread to
Eurasia, Africa, and South America.
Camels went extinct in North America 10,000 years
ago.
Today, we see true camels in Eurasia & Africa and
camel descendents (llamas, alpacas etc) in South
America.

51. Zoogeography
Geologic change is responsible for
much of the alteration in animal
distribution.

52. Zoogeography
Phylogenetic systematics allows us to reconstruct
histories of animal distributions.
Geographical distributions of closely related species are
mapped onto a cladogram to generate hypotheses of
the geographic history.

53. Zoogeography
Disjunct distributions are closely related
species that live in widely separated areas.
Dispersal – a population moves to a new
location.
Vicariance – environmental changes break
up a once continuous population into small
pockets.

54. Distribution by Dispersal
Dispersal involves emigration from one region and
immigration into another.
One way outward movement.
 Different from a periodic movement back & forth.
Active or passive
Center of origin
Explains movement of animal populations into
favorable habitats adjacent to the place of origin.

55. Distribution by Vicariance
Areas once joined may become separated by barriers.
Population becomes fragmented into smaller, isolated
populations.
Lava flows
Continental drift
Emergence of mountain ranges

56. Distribution by Vicariance
Vicariance by
continental drift
helps to explain the
disjunct distribution
of ratite birds.
Ancestral species
widespread
throughout Southern
Hemisphere.

57. Distribution by Vicariance
As the continents
moved apart, the
ancestral species was
fragmented into
disjunct populations
that evolved
independently
producing the
diversity seen today.

58. Continental Drift
The concept of continental drift
was proposed by Alfred Wegener
in 1912.
Not fully accepted until the
mechanism was found.

59. Continental Drift
Plate tectonics is the mechanism
of continental drift.
The earth’s surface is
composed of 6-10 rocky plates
which shift position on a more
malleable underlying layer.

60. Continental Drift
Pangaea – the single great landmass –
broke up 200 million years ago.
Two supercontinents resulted:
Laurasia – North America, Eurasia,
Greenland
Gondwana – South America, Africa,
Madagascar, Arabia, India, Australia,
New Guinea, Antarctica

61. Continental Drift
Continental drift explains several
puzzling distributions of animals.
Similarity between some
organisms in South America and
Africa.

62. Continental Drift - The Case of Marsupial
EvolutionMarsupials appeared about 100 million years ago in
South America.
They spread through Antarctica and Australia that were
at that time joined together.

63. Continental Drift - The Case of
Marsupial Evolution
Marsupials encountered placental mammals in North
America, could not compete, and became extinct.
The modern opossums are recent arrivals from South America.
The placental mammals expanded into South America,
but the marsupials were well established there.
About 50 million years ago, Australia drifted apart from
Antarctica and remained in isolation with only marsupials
to diversify on the continent.

64. Wallace’s Line
Wallace’s line
represents a
geographic
separation between
Asian and
Australian faunas.
A collision of
tectonic plates
brought formerly
distant land masses
closer together.

65. Temporary Land Bridges
Temporary land bridges
have been important
pathways for dispersal.
Land bridge connected
Asia and North America
across the Bering Strait.
Today, a land bridge
connects North and
South America

66. Climatic Cycles and Vicariance
Glacial cycles have occurred with durations of
20,000 to 100,000 years within the past three million
years.
Taxa sharing the same areas typically differ greatly in
evolutionary age and in phylogenetic branching
pattern.

67. Climatic Cycles and Vicariance
Cycling temperatures interact
with the habitat requirements of
animals.

68. Thank you