There are few places left on the planet where the impact of people has not been felt. We have explored and left our footprint on nearly every corner of the globe. As our population and needs grow, we are leaving less and less room for wildlife. Wildlife are under threat from many different kinds of human activities, from directly destroying habitat to spreading invasive species and disease. Most ecosystems are facing multiple threats. Each new threat puts additional stress on already weakened ecosystems and their wildlife.

1.  Introduction
Origin of oceans and continents
Plate tectonics and continental drift
 Distribution of animals in space and time
In space – horizontal or superficial
In time – geological or durational
- Anish Gawande
- Dr. Manisha Kayande

2. Introduction
Zoogeography, the branch of the science of biogeography that is concerned with the geographic
distribution of animal species. In addition to mapping the present distribution of species,
zoogeographers formulate theories to explain the distribution, based on information about geography,
physiography, climate, and geologic history, as well as knowledge of the evolutionary history and
relationships of the animals involved.

3. Origin of oceans and continents
The time period from the formation of the Earth (4.5 Ga) to the establishment of plate tectonics at the
beginning of the Proterozoic (2.5 Ga) remains largely hidden and unknown. During this time period, the
ocean, atmosphere, and continents formed, and the geochemical and physical processes that allowed
the development and evolution of life were established. Our knowledge of these beginnings is scant,
with theories changing as each new line of evidence emerges. Perhaps most troubling is that we have no
coherent, unified theory that simplifies our understanding of the Earth's beginnings.

4. Origin of oceans and continents
The key idea necessary for the development of a unified theory
that explains the origin of the ocean and continents is the
recognition that the timing of the growth of continental crust is
an earmark for the presence of abundant water on the surface of
the Earth and its entry into the mantle by subduction. Strontium
isotopes, europium anomalies, and zircon populations all suggest
that rapid growth of the continental crust did not begin until 3.0
Ga when the Earth was already 1.5 billion years old. The
implication is that widespread hydration of the oceanic crust did
not occur until about 3.0 Ga; thus volumes of water sufficient to
cover the Archean analogues to mid-ocean spreading ridges did
not exist prior to this time. No existing theory of ocean origin by
outgassing or early and rapid accretion on a young Earth survives
falsification. The unifying theory that explains both the origin of
the ocean and the continents is the slow and gradual
accumulation of water on the surface of the Earth by
extraterrestrial accretion.

5. Plate tectonics and continental drift
Plate tectonics is a scientific theory describing the large-scale motion of seven large plates and the
movements of a larger number of smaller plates of the Earth's lithosphere, since tectonic processes
began on Earth between 3 and 3.5 billion years ago. The model builds on the concept of continental
drift, an idea developed during the first decades of the 20th century. The geoscientific community
accepted plate-tectonic theory after seafloor spreading was validated in the late 1950s and early 1960s.

6. Plate tectonics and continental drift
The lithosphere, which is the rigid
outermost shell of a planet (the
crust and upper mantle), is
broken into tectonic plates. The
Earth's lithosphere is composed of
seven or eight major plates
(depending on how they are
defined) and many minor plates.
Where the plates meet, their
relative motion determines the
type of boundary: convergent,
divergent, or transform.
Earthquakes, volcanic activity,
mountain-building, and oceanic
trench formation occur along
these plate boundaries (or faults).
The relative movement of the
plates typically ranges from zero
to 100 mm annually.

7. Plate tectonics and continental drift
• In the early 20th century, geologists began to realize
that the Earth’s outer crust is not one solid piece like
an egg’s shell. The crust is broken up into giant
tectonic plates that ride atop the magma, hot melted-
rock material that makes up much of the interior of
the Earth. Over millions of years, the continents drift
into new configurations.
• Convection in the molten rock of Earth’s mantle drives
the movement of the plates. Hotter material rises to
the surface, while cooler material sinks toward the
core. This creates pushing and spreading apart at mid-
ocean ridges and subduction (sinking) of one plate
under another at subduction zones.
• In the early 20th century, German researcher Alfred
Wegener noted that fossil remains of the same extinct
animal or plant can be found across several continents
that are not now adjacent to one another. This
suggests that in the distant past, the configuration of
continents was different than it is today, a theory
Wegener called “continental drift.”

8. Plate tectonics and continental drift
Continental drift is the movement of the Earth's continents relative to each other, thus appearing to
"drift" across the ocean bed. The speculation that continents might have 'drifted' was first put forward
by Abraham Ortelius in 1596. The concept was independently and more fully developed by Alfred
Wegener in 1912, but his theory was rejected by some for lack of a mechanism. The idea of continental
drift has been subsumed by the theory of plate tectonics, which explains how the continents move.

9. Plate tectonics and continental drift
The theory of continental drift
Wegener thought all the continents were once joined together in
an “Super continent" before breaking up and drifting to their
current positions. But geologists soundly denounced Wegener's
theory of continental drift after he published the details in a 1915
book called "The Origin of Continents and Oceans." Part of the
opposition was because Wegener didn't have a good model to
explain how the continents moved apart.
Alfred Wegener
(1924–1930)
Super continent

10. Distribution of animals in space and time
Species distribution is the manner in which a biological taxon is spatially arranged. Species distribution is
not to be confused with dispersal, which is the movement of individuals away from their area of origin
or from centers of high on density. A similar concept is the species range. A species range is often
represented with a species range map. Bio-geographers try to understand the factors determining a
species' distribution. The pattern of distribution is not permanent for each species. Distribution patterns
can change seasonally, in response to the availability of resources, and also depending on the scale at
which they are viewed. Dispersion usually takes place at the time of reproduction. Populations within a
species are trans located through many methods, including dispersal by people, wind, water and
animals. Humans are one of the largest distributors due to the current trends in globalization and the
expanse of the transportation industry. For example, large tankers often fill their ballasts with water at
one port and empty them in another, causing a wider distribution of aquatic species.

11. Distribution of animals in space and time
 Distribution in space: This is the distribution
of animals in earth surface including land
and water. This is again sub divided into two
types
 Geographical or Horizontal Distribution: The
distribution of animals in lands and fresh
water of different continents and islands is
known as geographical or horizontal
distribution.
 Bathymetric or vertical Distribution: The
distribution of animals in the vertical surface
of land and water is called bathymetric or
horizontal distribution. This is again
distributed into following types:
1. Limnobiotic Distribution: It is distribution of
animals in fresh water.
2. Holobiotic Distribution: Distribution of
animals in sea.
3. Geobiotic Distribution: Distribution of
animal on land.

12. Distribution of animals in space and time
 Distribution in Time: The distribution of animal species in
different historic time period of earth is known as distribution
in time. This can be only studied through fossil study. This type
of distribution only divided into four types
 Arctic Distribution: In this time phase number of species is
found in arctic or Antarctic with no existence of species in
intermediate water. This type of distribution is also called
bipolar distribution and phenomenon is called bipolarity.
Example: Botrynema (coelenterats), Lampta (coelenterats),
Clione (Molluscs), Peripatus (Arthropoda)
 Tropical Distribution: The distribution of animals in between
the landmass of tropic of cancer and tropic of Capricorn is
called tropical distribution. This region has maximum bio
diversity.
 Continuous Distribution: This is also called cosmopolitan
distribution when an animal species is found over a wide area.
Example: The green mussel (Mollusca), Brine Shrimp
(Arthropoda)
 Discontinuous Distribution: When different species of same
genus or different animals of same species are distributed in
different part of earth is called discontinuous distribution.

13. Thank you …… !!