EVIDENCE OF EVOLUTION

5 TYPES OF EVOLUTION:

1. Ancient Organism Remain –

Preserved remains of species whose bodies were buried in sediments, such as sand and mud,
under ancient seas lakes, rivers, trees and Ice.

2.

Minerals have replaced A paleontologist This insect became trapped This frozen baby wooly
the plant matter to form removes fossil from in tree sap, which then mammoth probably lived
this petrified wood. the rock. hardened into amber. 22,000 years ago.

Fossil Layers –
Fossil layers are fossils that formed in sedimentary rock.
Sedimentary rock is rock that is formed in layers by the depositing and pressing of sediments on
top of each other.
Sediments are any loose material that gets broken away and carried: pieces of rocks, pebbles,
sand, clay, silt, boulders, dead organisms, animals, plants, shells, insects.

When sediments move and settle somewhere, they are being deposited.
When, over a long time, layers and layers of sediments get deposited on top of each other, the
weight of the top layers presses down on the bottom layers, forming them into rock called
sedimentary rock.

Because sediments sometimes include once-living organisms, sedimentary rock often contains a
lot of fossils.

3.

Similarities Among Living Organisms –

Layers of sedimentary A sandstone fossil of a trilobite,

A fossil of an ancient sea-lily,
rocks which probably lived 500 to 600
which probably lived 90 million
million years ago.
years ago.
 that organisms are similar to each other, but not exactly the same. Similar organisms have
differences that help them adapt to their environments.

The sea gull and the pelican are very similar in

appearance, behavior and DNA. The differences, such as beak shape and size, show that each bird
adapted to fit its own environment.

Many Organisms Have Similar Body Plans:

for example:

Horses', donkeys', and zebras' -- bodies are set up in pretty much the same way, because they are
descended from a common ancestor.

All insects -- have heads, abdomens, and thoraxes, antennae, six legs, and wings.

All birds -- have feathers, beaks, and wings, but are different because they had to adapt to different
environments.

Family snapshot - chimps and humans are very closely

related.

4. Similarities of Embryos
The study of one type of evidence of evolution is called embryology, the study of embryos. An
embryo is an unborn (or unhatched) animal or human young in its earliest phases. Embryos of
many different kinds of animals: mammals, birds, reptiles, fish, etc. look very similar and it is
often difficult to tell them apart. Many traits of one type of animal appear in the embryo of
another type of animal. For example, fish embryos and human embryos both have gill slits. In
fish they develop into gills, but in humans they disappear before birth.
 EXTINCTION OF SPECIES

Extinction - is the death of all members of a species of plants, animals, or other organisms. One of the most
dramatic examples of a modern extinction is the passenger pigeon.

Passenger pigeon or Wild pigeon – its common name is derived from the French word passager meaning
“passing by”. Due to migratory habits of species.

The last passenger pigeon, named Martha, died in the Cincinnati Zoological Garden in 1914, and was
donated to the Smithsonian Institution.

Extinct Species List

* 1690 Dodo bird -- extinct from predation by introduced pigs and cats

* 1768 Stellar’s sea cow -- extinct from hunting for fur and oil

* 1870 Labrador duck -- extinct from human competition for mussels and other shellfish

* 1900 Rocky mountain locust -- extinct from habitat conversion to farmland

* 1936 Tasmanian wolf -- extinct from hunting, habitat loss, and competition with dogs

* 1952 Deepwater cisco fish --extinct from competition and predation by introduced fishes

* 1962 Hawaii chaff flower -- extinct from habitat conversion to military installations

* 1989 Golden toad -- extinct from climate change or other impacts

* 2004 St. Helena olive tree -- extinct from logging and plantations

Five Mass Extinctions

1. End of the Cretaceous (66 million years ago): Extinction of many species in both marine and
terrestrial habitats including pterosaurs, mosasaurs and other marine reptiles, many insects, and
all non-Avian dinosaurs. The scientific consensus is that this mass extinction was caused by
environmental consequences from the impact of a large asteroid hitting Earth in the vicinity of
what is now Mexico.

2. Late Triassic (199 million years ago): Extinction of many marine sponges, gastropods, bivalves,
cephalopods, brachiopods, as well as some terrestrial insects and vertebrates. The extinction
coincides with massive volcanic eruptions along the margins of what is now the Atlantic Ocean.

3. End Permian (252 million years ago): Earth’s largest extinction event, decimating most marine
species such as all trilobites, plus insects and other terrestrial animals. Most scientific evidence
suggests the causes were global warming and atmospheric changes associated with huge
volcanic eruptions in what is now Siberia.
 4. Late Devonian (378 million years ago): Extinction of many marine species, including corals,
brachiopods, and single-celled foraminiferans, from causes that are not well understood yet.

5. Late Ordovician (447 million years ago): Extinction of marine organisms such as some
bryozoans, reef-building brachiopods, trilobites, graptolites, and conodonts as a result of global
cooling, glaciation, and lower sea levels.

Sixth Mass Extinction

Early humans worked cooperatively to trap and slaughter large animals in pits. About the same time,
humans began farming, settling down and making drastic changes in the habitats of other species.
Starting in the 1800s, industrialization drove up extinction rates and has continued to do so