Transcript Unit 5: Evolution Notes

Unit 5: Evolution Notes
Unit 5: Evolution of Living Things
5.0 Fossils provide evidence of earlier life.
5.1 Scientists use the information in rocks and
fossils to learn about the changes in life on
Earth.
5.2 The first living things appeared on Earth
about 3.8 billion years ago.
5.3 The first living things on Earth were
single-celled organisms that lived in the
ocean called cyanobacteria.
5.4 The earliest life forms were Prokaryotes.
5.5 Prokaryotes: a single-celled organism without
a nucleus.
5.6 Eukaryotes: a single or multicellular organism
with a nucleus.
5.7 The first animals were jellyfish.
5.8 For most of the history of life on Earth, life
existed only in the ocean.
5.9 The first animals on land were insects.
5.10 Extinction: is the loss of all the members
of one type of animal.
5.11 Mass Extinction: One of several periods
in Earth’s history when large numbers of
different animals become extinct at nearly
the same time.
5.12 Mass Extinctions may be caused by
volcanoes or by asteroid impacts.
5.13 Biological Evolution: is the process by
which animals change over time.
5.14 Biological evolution is the result of
changes in genetic material (DNA).
5.15 The changes in DNA are passed on from
one generation to the next.
5.16 Charles Darwin: was a naturalist who
studied evolution and developed an
explanation for the process which he called
natural selection.
5.17 Charles Darwin published the book: The
Origins of Species. This book was about his 5
year journey around the world describing his
observations and collections about nature.
5.18 Natural Selection: the process in which
individuals with certain traits survive and
reproduce more than individuals without
these traits.
5.19 Population: is a group of individuals of the
same species that live in a particular area.
5.20 Overproduction: is the process in nature
where organisms usually produce more
offspring that their environment can support.
Example: Fish lay thousands of eggs.
5.21 Genetic Variation: Differences in DNA in
a population.
5.22 Genetic Variation comes from the mix of
DNA from both parents.
**Just think are you exactly like your
brother or sister? Everyone is a little
different.
5.23 Adaptation: An inherited trait that gives
an organism an advantage in its environment.
Example: A fish tail to swim faster.
A long bird beak to get food.
5.24 Environmental Factors: Conditions that
affect survival, such as food, predators, and
disease.
5.25 Animals with an adaptation useful in
their environment have a good chance of
living long enough to reproduce and pass
on their DNA to offspring.
5.26 Speciation: The evolution of a new
animal from an existing animal.
5.27 Darwin’s observations studied how the
isolation of populations may lead to the
rise of new species or animals.
5.28 When populations are too genetically
different to reproduce, they are considered
to be different animals.
5.29 Population size is limited by
environmental conditions.
5.30 Populations increase through births and
immigration.
5.31 Immigration: is the movement of
individuals into a population.
5.32 Many factors limit population size such
as deaths or emigration.
5.33 Emigration: is the movement of
individuals out of a population.
5.34 Limiting Factor: a factor or condition
that prevents the continuing growth of a
population.
5.35 These factors include food, water, space,
shelter, predators, storms, or fires.
5.36 Competition: is a contest between
individuals or animals for a location and
resources.
5.37 Competition occurs naturally
between living organisms which live in
the same environment.
Example: Animals compete over
water, food, and mates.
5.38 Predator: An organism that lives by eating
other organisms.
5.39 Disease: is an abnormal condition of an
organism that destroys bodily functions.
5.40 Catastrophic Events: is an event that
causes large destruction and kill lots of
organisms.
Example: Fires, Earthquakes, Floods
5.41 The survival of a species depends on its
ability to adapt to change.
5.42 The extinction of one animal allows
room for another animal to live better.
5.43 Extinction is apart of the cycle of life on
Earth.
5.44 Scientific Theory: An explanation about
the natural world that is based on a wide
range of scientific evidence.
5.45 Scientific Theories are widely accepted
by scientists around the world.
Evidence to Support Evolution
5.46 The theory of evolution is supported by
many types of evidence including: fossil
evidence, biological evidence, and genetic
evidence.
Fossil Evidence
5.47 The fossil record shows the history of life on
Earth and the evolution of modern animals.
5.48 Ancestor: An early form of an organism
from which later forms evolve.
5.49 Scientist use fossils to compare how
different animals looked throughout time.
Biological Evidence
5.50 Biological similarities among animals
give evidence that animals evolved from a
common ancestor.
5.51 Some animals share similar organs and
bones, which could mean they came from a
common ancestor.
5.52 Vestigial Organs: are structures that were fully
developed in ancestral organisms but are small
and unused in later animals.
Example: Whales have tiny leg bones.
5.53 Comparative Anatomy: The study of the
similarities and differences of the physical
structures of animals.
5.54 Different animals may have similar
structures but use the structures in
different ways.
5.55 Embryo: is an animal in an early stage of
development.
5.56 The study of embryos show that animals
that look very different as adults are similar
during early development.
Genetic Evidence
5.57 Scientists compare DNA between
different animals. The closer the DNA
demonstrates that the animals are more
closely related and share a common
ancestor.