Earth has been home to living things for about 3.8 billion years. Fossils provide evidence about the history of life on Earth, showing that unicellular organisms were the first, followed later by multicellular organisms in oceans and then life on land. Species have changed over this immense period of time through the process of evolution by natural selection, with traits becoming adapted to different environments and new species emerging. Mass extinctions that eliminated a large portion of species were sometimes followed by explosions in new forms of life.
In line with generally accepted theories of evolution, Dinosaur extinction is currently believed to be due to climate change due to various causes. However this is not correct, being inconsistent with known facts. There are only two possibilities. Either Dinosaurs evolved to their extinction or evolved to some other phyletic lines or species with which ancestor – descendent relationship can’t be presently demonstrated.
Author: Dr Mahesh C. Jain is a practicing medical doctor and has written the book “Encounter of Science with Philosophy – A synthetic view”. The book begins with first chapter devoted to scientifically valid concept of God and then explains cosmic phenomena right from origin of nature and universe up to origin of life and evolution of man. The book includes several chapters devoted to auxiliary concepts and social sciences as corollaries to the concept of God. This is the only book which deals with origin of nature and universe from null or Zero or nothing. Chapter 30 of the book is about Evolution of Life wherein author has worked out a new theory about evolution of life.
Visit:http:// www.sciencengod.com
http://www.sciencengod.com/clipboard.htm
A condensed story of how biological evolution is a consequence of cosmological evolution. This has been created to engineer the young with an objective belief system that is empirically factually verifiable
Introduction to Biogeography of the Global GardenScott St. George
Biogeography uses ideas from biology, geography and history to explain the panorama of life on Earth. This course provides students with a broad introduction to important concepts and issues in ecology and environmental science. Over the semester, we’ll investigate how weather and climate affects the distribution of species, how individuals interact with their own species and others, and discuss why species expand or go extinct. Within this framework, we’ll also examine the many ways humans, either as individuals or in groups, act as agents of biotic change.
In line with generally accepted theories of evolution, Dinosaur extinction is currently believed to be due to climate change due to various causes. However this is not correct, being inconsistent with known facts. There are only two possibilities. Either Dinosaurs evolved to their extinction or evolved to some other phyletic lines or species with which ancestor – descendent relationship can’t be presently demonstrated.
Author: Dr Mahesh C. Jain is a practicing medical doctor and has written the book “Encounter of Science with Philosophy – A synthetic view”. The book begins with first chapter devoted to scientifically valid concept of God and then explains cosmic phenomena right from origin of nature and universe up to origin of life and evolution of man. The book includes several chapters devoted to auxiliary concepts and social sciences as corollaries to the concept of God. This is the only book which deals with origin of nature and universe from null or Zero or nothing. Chapter 30 of the book is about Evolution of Life wherein author has worked out a new theory about evolution of life.
Visit:http:// www.sciencengod.com
http://www.sciencengod.com/clipboard.htm
A condensed story of how biological evolution is a consequence of cosmological evolution. This has been created to engineer the young with an objective belief system that is empirically factually verifiable
Introduction to Biogeography of the Global GardenScott St. George
Biogeography uses ideas from biology, geography and history to explain the panorama of life on Earth. This course provides students with a broad introduction to important concepts and issues in ecology and environmental science. Over the semester, we’ll investigate how weather and climate affects the distribution of species, how individuals interact with their own species and others, and discuss why species expand or go extinct. Within this framework, we’ll also examine the many ways humans, either as individuals or in groups, act as agents of biotic change.
Our best evidence to data suggests that the Earth formed 4.6 billion .pdfarorasales234
Our best evidence to data suggests that the Earth formed 4.6 billion years ago. What life forms
existed on Earth during the following periods. (Match the correct answer to each question; you
may use each answer more than once.) What happened during the first billion years (4.5-3.6
billion years ago)? What happened during the second billion years (3.6-2.6 billion years ago)?
What happened during the third billion years (2.6-1.6 billion years ago)? What happened during
the third billion years (2.6-1.6 billion years ago)? What happened during the fourth billion years
(1.6-0.6 billion years ago)? What happened during the last 600 million years (0.6 billion years
ago to present)? A. no life existed B. unicellular life appeared C. unicellular life forms were the
only living things on Earth d. multicellular life appeared. E. dinosaurs dominated the entire
period F. mammals dominated the entire period
Solution
What happened during the first billion years? (4.6 -3.6 billion years ago?) A. no life existed.
Reason: Earth was formed over 4.6 billion years ago.Before that there was no life.
What happened during the second billion years? (3.6 -2.6 billion years ago?) C.Unicellular life
forms were the only living things on earth.
Reason:Unicellular life appeared first about 3.6 billion years ago.
What happened during the third billion years? (2.6-1.6 billion years ago?) B.unicellular life
appeared.
Reason:Unicellualr life appeared on earth during this period.
What happened during the fourth billion years? (1.6 -0.6 billion years ago?) D.multicellular life
appeared.
Reason:Multicellular life appeared 1.5 billion years ago.
What happened during the last 600 million years (0.6 billion years ago to pesent?) E and F.
Dinosaurs dominated the entire period and mammals dominated the entire period.
Reason: Both dinosaurs and mammals appeared in this period .Dinosaurs appeared first and then
mammals appeared before extinction of dinosaurs..
Air, ground, and water pollution is a concern now and in the future. Our good health depends on a cleaner environment. My Humans Affect Atmosphere Lab is an example of my understanding of environmental science and the investigative nature of science in general. The intention of this field lab is for students to observe and record the atmospheric discharge from U.S. Steel Gary Works. The purpose is not to single-out U.S. Steel, although air pollution is often associated with steel production. The purpose is to observe and record pollution in general.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Home assignment II on Spectroscopy 2024 Answers.pdf
Brittany Brown --Evolution
1. Earth’s Change Over TimeEarth’s Change Over Time
(Evolution)(Evolution)
Brittany BrownBrittany Brown
Biology 1-5Biology 1-5thth
periodperiod
May 1,2007May 1,2007
2. IntroductionIntroduction
In life there have been different theories asIn life there have been different theories as
to how life came about. Many scientists haveto how life came about. Many scientists have
wonder how Earth continued to change over awonder how Earth continued to change over a
period of time. In Mr. Parr class he has ask hisperiod of time. In Mr. Parr class he has ask his
students to present a power point presentationstudents to present a power point presentation
and the Earth Change Over Time or somethingand the Earth Change Over Time or something
related to that topic. These are the followingrelated to that topic. These are the following
students in his 5students in his 5thth
period class:period class:
3. Key ConceptsKey Concepts
Earth has been home to living things forEarth has been home to living things for
about 3.8 billion years.about 3.8 billion years.
Species change over time.Species change over time.
Many types of evidence support evolution.Many types of evidence support evolution.
6. Earth’s Change Over TimeEarth’s Change Over Time
(Evolution)(Evolution)
Earth has been home to living thingsEarth has been home to living things
for about 3.8 billion years.for about 3.8 billion years.
7. Earth has been home to livingEarth has been home to living
things for about 3.8 billion years.things for about 3.8 billion years.
Fossils provide evidence about the history of lifeFossils provide evidence about the history of life
on Earth. Most fossils are hard body parts oron Earth. Most fossils are hard body parts or
bone. Others form when minerals replace thebone. Others form when minerals replace the
remains of organisms. Fossils also include printsremains of organisms. Fossils also include prints
left by organisms, such as footprints. Very rarely,left by organisms, such as footprints. Very rarely,
a fossil is the preserved remains of an organism,a fossil is the preserved remains of an organism,
such as a wooly mammoth in ice or an insectsuch as a wooly mammoth in ice or an insect
preserved in sap.preserved in sap.
8. Earth has been home to living thingsEarth has been home to living things
for about 3.8 billion years. (cont.)for about 3.8 billion years. (cont.)
Relative ageRelative age is how old a rock oris how old a rock or
fossil is compared to other rocksfossil is compared to other rocks
or fossils. Ancient organismsor fossils. Ancient organisms
settled to the bottom of a body ofsettled to the bottom of a body of
water in layers of mud and sandwater in layers of mud and sand
that later formed rock.that later formed rock.
9. Absolute ageAbsolute age is the actual age ofis the actual age of
the rock or fossil. To measure thethe rock or fossil. To measure the
absolute age of a fossil, scientistsabsolute age of a fossil, scientists
measure its radioactivity. Overmeasure its radioactivity. Over
time, radioactive materialtime, radioactive material
disappears. The older the fossil,disappears. The older the fossil,
the less radioactive material itthe less radioactive material it
has.has.
Earth has been home to living thingsEarth has been home to living things
for about 3.8 billion years. (cont.)for about 3.8 billion years. (cont.)
10. Earth has been home to living thingsEarth has been home to living things
for about 3.8 billion years. (cont.)for about 3.8 billion years. (cont.)
TheThe fossil recordfossil record is all of theis all of the
information that can be gatheredinformation that can be gathered
from the fossils in a particularfrom the fossils in a particular
location. Scientists can then uselocation. Scientists can then use
the record to identify whichthe record to identify which
species lived and died duringspecies lived and died during
different periods of time.different periods of time.
11. Earth has been home to living things forEarth has been home to living things for
about 3.8 billion years. (cont.)about 3.8 billion years. (cont.)
Unicellular organisms, made ofUnicellular organisms, made of
only one cell, were the first livingonly one cell, were the first living
things on Earth. They appearedthings on Earth. They appeared
about 3.8 billion years ago. Theabout 3.8 billion years ago. The
atmosphere then did not have asatmosphere then did not have as
much oxygen as it does now.much oxygen as it does now.
Some of the early organismsSome of the early organisms
added oxygen to the atmosphere.added oxygen to the atmosphere.
12. Earth has been home to living things forEarth has been home to living things for
about 3.8 billion years. (cont.)about 3.8 billion years. (cont.)
Multicellular organismsMulticellular organisms began to livebegan to live
in Earth's oceans about 1.2 billionin Earth's oceans about 1.2 billion
years ago. The fossil record showsyears ago. The fossil record shows
that the earliest multicellularthat the earliest multicellular
organisms were tiny seaweeds. Theorganisms were tiny seaweeds. The
earliest animals were similar toearliest animals were similar to
jellyfish.jellyfish.
13. Earth has been home to living things forEarth has been home to living things for
about 3.8 billion years. (cont.)about 3.8 billion years. (cont.)
Life appeared on land about 500 million yearsLife appeared on land about 500 million years
ago. Before that, all living things met their needsago. Before that, all living things met their needs
while living in water. Simple plants were the firstwhile living in water. Simple plants were the first
land-dwelling organisms, getting water from theland-dwelling organisms, getting water from the
soil through roots. The plants in turn providedsoil through roots. The plants in turn provided
food and shelter to the first fungi and insects onfood and shelter to the first fungi and insects on
land. After insects, amphibians and reptilesland. After insects, amphibians and reptiles
began to live on land, followed by birds andbegan to live on land, followed by birds and
mammals.mammals.
14. Earth has been home to living things forEarth has been home to living things for
about 3.8 billion years. (cont.)about 3.8 billion years. (cont.)
A species becomes extinct whenA species becomes extinct when
all members of the species haveall members of the species have
died. Many species have onlydied. Many species have only
been seen as fossils becausebeen seen as fossils because
they became extinct long ago. Athey became extinct long ago. A
mass extinction is a period whenmass extinction is a period when
a large number of speciesa large number of species
become extinct in a very shortbecome extinct in a very short
time.time.
15. Earth has been home to living things forEarth has been home to living things for
about 3.8 billion years. (cont.)about 3.8 billion years. (cont.)
TheThe Permian ExtinctionPermian Extinction occurred aboutoccurred about
250 million years ago. Approximately 90250 million years ago. Approximately 90
percent of the species in the ocean, aspercent of the species in the ocean, as
well as many land-dwelling animals,well as many land-dwelling animals,
became extinct. This mass extinction maybecame extinct. This mass extinction may
have been caused by climate change duehave been caused by climate change due
to all of Earth's landmasses joiningto all of Earth's landmasses joining
together to form a single, enormoustogether to form a single, enormous
continent.continent.
17. Earth has been home to living things forEarth has been home to living things for
about 3.8 billion years. (cont.)about 3.8 billion years. (cont.)
TheThe Cretaceous ExtinctionCretaceous Extinction
occurred about 65 million yearsoccurred about 65 million years
ago. More than half of all theago. More than half of all the
species on Earth, includingspecies on Earth, including
dinosaurs, became extinct. Thisdinosaurs, became extinct. This
mass extinction may have beenmass extinction may have been
caused by a meteorite, a giantcaused by a meteorite, a giant
space object, colliding with Earth.space object, colliding with Earth.
18. Earth has been home to living things forEarth has been home to living things for
about 3.8 billion years. (cont.)about 3.8 billion years. (cont.)
Mass extinctionsMass extinctions are oftenare often
followed by the appearance of afollowed by the appearance of a
large number of new species. Forlarge number of new species. For
example, the extinction ofexample, the extinction of
dinosaurs may have allowed newdinosaurs may have allowed new
species of mammals to developspecies of mammals to develop
and thrive.and thrive.
19. Earth’s Change Over TimeEarth’s Change Over Time
(Evolution)(Evolution)
Species change over time.Species change over time.
20. Species change over time.Species change over time.
Evolution is the process by which species changeEvolution is the process by which species change
over time.over time.
In the early 1800s, Jean-In the early 1800s, Jean-
Baptiste de LamarckBaptiste de Lamarck
proposed a theory ofproposed a theory of
evolution. He suggestedevolution. He suggested
that organisms developthat organisms develop
traits during their livestraits during their lives
and then pass them on toand then pass them on to
offspring. For example, aoffspring. For example, a
giraffe stretches its neckgiraffe stretches its neck
to get high leaves, andto get high leaves, and
then passes that longerthen passes that longer
neck to the nextneck to the next
generation. But Lamarckgeneration. But Lamarck
could not find evidence tocould not find evidence to
support his theory.support his theory.
21. Species change over time.Species change over time.
Evolution is the process by which species changeEvolution is the process by which species change
over time.over time.
Charles Darwin was aCharles Darwin was a
naturalist who traveled to thenaturalist who traveled to the
Galapagos Islands in the lateGalapagos Islands in the late
1830s. Darwin's theory of1830s. Darwin's theory of
evolution developed fromevolution developed from
observing different species ofobserving different species of
tortoises and finches on thetortoises and finches on the
Galapagos Islands. ForGalapagos Islands. For
example, he found someexample, he found some
finches with beaks useful forfinches with beaks useful for
cracking seeds and others withcracking seeds and others with
beaks useful for capturingbeaks useful for capturing
insects. Darwin wonderedinsects. Darwin wondered
whether the birds had evolvedwhether the birds had evolved
differently because they weredifferently because they were
in different environments.in different environments.
22. Species change over timeSpecies change over time..
A group of organisms may evolve due toA group of organisms may evolve due to
artificial selectionartificial selection
artificial selectionartificial selection is the process thatis the process that
breeders use to produce animals withbreeders use to produce animals with
desirable traits. A breeder will selectdesirable traits. A breeder will select
individuals with desired traits from aindividuals with desired traits from a
group, then allow only those individuals togroup, then allow only those individuals to
mate. In the next generation, the breedermate. In the next generation, the breeder
will again select the individuals withwill again select the individuals with
desired traits and mate them to producedesired traits and mate them to produce
the next generation.the next generation.
23. Species change over timeSpecies change over time..
Natural SelectionNatural Selection
Natural selectionNatural selection is the hypothesis Darwinis the hypothesis Darwin
developed based on his observations fromdeveloped based on his observations from
his voyage and from his hobby of breedinghis voyage and from his hobby of breeding
pigeons. Darwin proposed that memberspigeons. Darwin proposed that members
of a species that are best suited to theirof a species that are best suited to their
environment survive and reproduce at aenvironment survive and reproduce at a
higher rate than other members of thehigher rate than other members of the
species. This process is called naturalspecies. This process is called natural
selection.selection.
24. Species change over time.Species change over time.
The process of natural selection depends on a fewThe process of natural selection depends on a few
key principles.key principles.
OverproductionOverproduction is theis the
idea that mostidea that most
organisms produceorganisms produce
more offspring thanmore offspring than
can possibly survive.can possibly survive.
For example, aFor example, a
female salmon laysfemale salmon lays
thousands of eggs,thousands of eggs,
but only severalbut only several
dozen will survive todozen will survive to
adulthood, and evenadulthood, and even
fewer will reproduce.fewer will reproduce.
25. The process of natural selection depends on a fewThe process of natural selection depends on a few
key principles.key principles.
VariationVariation is the naturalis the natural
differences in traitsdifferences in traits
among the members of aamong the members of a
species. Some mightspecies. Some might
have slightly larger fins,have slightly larger fins,
others different patternsothers different patterns
of spots. Mutations areof spots. Mutations are
changes in geneticchanges in genetic
material that cause amaterial that cause a
variation. Variations, duevariation. Variations, due
either to mutation or theeither to mutation or the
random combination ofrandom combination of
genes from parents, aregenes from parents, are
passed from onepassed from one
generation to the next.generation to the next.
26. Species change over time.Species change over time.
The process of natural selection depends on a fewThe process of natural selection depends on a few
key principles.key principles.
AnAn adaptationadaptation is anyis any
inherited trait that givesinherited trait that gives
an organism anan organism an
advantage in its particularadvantage in its particular
environment. Anenvironment. An
adaptation is a variationadaptation is a variation
that makes an individualthat makes an individual
better able to survive thanbetter able to survive than
others. For example, aothers. For example, a
slight change in theslight change in the
shape of a fin might makeshape of a fin might make
a fish swim faster anda fish swim faster and
avoid predators.avoid predators.
27. Species change over time.Species change over time.
The process of natural selection depends on a fewThe process of natural selection depends on a few
key principles.key principles.
SelectionSelection is the processis the process
that passes the mostthat passes the most
successful variations, orsuccessful variations, or
adaptations, into the nextadaptations, into the next
generation. Of thegeneration. Of the
organisms that thenorganisms that then
survive to reproduce,survive to reproduce,
more and more of themmore and more of them
will have the adaptation.will have the adaptation.
The favorable traits areThe favorable traits are
"selected" for the next"selected" for the next
generations. In this way,generations. In this way,
the species as a wholethe species as a whole
becomes more suited tobecomes more suited to
its environment.its environment.
28. Species change over time.Species change over time.
The process of natural selection depends on a fewThe process of natural selection depends on a few
key principles.key principles.
SpeciationSpeciation is the evolution of a new species fromis the evolution of a new species from
an existing species. Speciation can occur whenan existing species. Speciation can occur when
the environment changes. When geneticthe environment changes. When genetic
changes within two groups of the same specieschanges within two groups of the same species
build up, the two groups may not be able tobuild up, the two groups may not be able to
interbreed anymore. When this happens, twointerbreed anymore. When this happens, two
different species have formed and speciationdifferent species have formed and speciation
has occurred. The diagrams show how threehas occurred. The diagrams show how three
species of cichlid fish evolved from one originalspecies of cichlid fish evolved from one original
species in Lake Tanganyika.species in Lake Tanganyika.
29. Species change over time.Species change over time.
The process of natural selection depends on a fewThe process of natural selection depends on a few
key principles.key principles.
IsolationIsolation is essential to speciation. For a speciesis essential to speciation. For a species
to separate, two groups must be prevented fromto separate, two groups must be prevented from
reproducing with one another. A geographicreproducing with one another. A geographic
boundary, such as a mountain range or ocean,boundary, such as a mountain range or ocean,
can result in isolation. The cichlids in Lakecan result in isolation. The cichlids in Lake
Tanganyika and the finches Darwin observed inTanganyika and the finches Darwin observed in
the Galapagos Islands are examples of isolationthe Galapagos Islands are examples of isolation
leading to new species.leading to new species.
30. Earth’s Change Over TimeEarth’s Change Over Time
(Evolution)(Evolution)
Many types of evidenceMany types of evidence
support evolution.support evolution.
31. Many types of evidence supportMany types of evidence support
evolution.evolution.
AA theorytheory is a widely acceptedis a widely accepted
statement, based on scientificstatement, based on scientific
evidence, that helps explain aevidence, that helps explain a
group of facts. Darwin's theory ofgroup of facts. Darwin's theory of
evolution is widely acceptedevolution is widely accepted
because it is supported by fossilbecause it is supported by fossil
evidence, biological evidence,evidence, biological evidence,
and genetic evidence.and genetic evidence.
32. Many types of evidenceMany types of evidence
support evolution.support evolution.
Evidence from fossils supports evolution.Evidence from fossils supports evolution.
An ancestor is an early form of anAn ancestor is an early form of an
organism from which later forms descend.organism from which later forms descend.
According to the theory of evolution,According to the theory of evolution,
different species should have commondifferent species should have common
ancestors. Fossil evidence supports thisancestors. Fossil evidence supports this
idea. For example, modern plants andidea. For example, modern plants and
modern algae share characteristics withmodern algae share characteristics with
fossil algae that point to a commonfossil algae that point to a common
33. Many types of evidenceMany types of evidence
support evolution.support evolution.
Biological evidence supportsBiological evidence supports
evolution. Biological evidenceevolution. Biological evidence
includes the structure of livingincludes the structure of living
things and how living thingsthings and how living things
develop into adults.develop into adults.
34. Many types of evidenceMany types of evidence
support evolution.support evolution.
Vestigial organsVestigial organs areare
physical structures thatphysical structures that
were fully developed andwere fully developed and
functional in an earlierfunctional in an earlier
group of organisms butgroup of organisms but
are reduced and unusedare reduced and unused
in later species. Thesein later species. These
vestigial organs indicatevestigial organs indicate
that the organism had anthat the organism had an
ancestor that needed theancestor that needed the
trait, and can show howtrait, and can show how
the modern organism andthe modern organism and
the ancestor are related.the ancestor are related.
35. Many types of evidenceMany types of evidence
support evolution.support evolution.
Similar structuresSimilar structures with different functions indicate thatwith different functions indicate that
organisms shared a common ancestor. For example, theorganisms shared a common ancestor. For example, the
illustrations show that geckos, bats, and manatees haveillustrations show that geckos, bats, and manatees have
similar bones in their forelimb. A shorter bone leads fromsimilar bones in their forelimb. A shorter bone leads from
the shoulder to a joint. From the joint, the longer bonethe shoulder to a joint. From the joint, the longer bone
leads to a wrist. Because the three organisms live in veryleads to a wrist. Because the three organisms live in very
different environments, the similar structures havedifferent environments, the similar structures have
evolved in very different ways.evolved in very different ways.
36. Many types of evidenceMany types of evidence
support evolution.support evolution.
Similarities in development of different species that areSimilarities in development of different species that are
unlike as adults indicate a common ancestor. Forunlike as adults indicate a common ancestor. For
example, a chicken, a rabbit, and a salamander areexample, a chicken, a rabbit, and a salamander are
three very different animals. However, their embryosthree very different animals. However, their embryos
look very similar. As the embryos develop, they becomelook very similar. As the embryos develop, they become
more different. This evidence indicates that manymore different. This evidence indicates that many
animals must share a common ancestor whose embryoanimals must share a common ancestor whose embryo
started developing in a similar way.started developing in a similar way.
37. Many types of evidenceMany types of evidence
support evolutionsupport evolution
Genetic evidenceGenetic evidence
supports the theory ofsupports the theory of
evolution.evolution.
38. Many types of evidenceMany types of evidence
support evolutionsupport evolution
DNA contains the genetic materialDNA contains the genetic material
found in all cells. It contains a codefound in all cells. It contains a code
that a cell uses to function properly.that a cell uses to function properly.
The code is a pattern of four chemicalThe code is a pattern of four chemical
units called bases, represented by theunits called bases, represented by the
letters A, T, C, and G.letters A, T, C, and G.
39. Many types of evidenceMany types of evidence
support evolution.support evolution.
GenesGenes are segments of DNA that relate to aare segments of DNA that relate to a
specific trait or function of an organism. Forspecific trait or function of an organism. For
example, the clock gene is found in manyexample, the clock gene is found in many
mammals and relates to how the mammalmammals and relates to how the mammal
sleeps and wakes. The clock gene can be usedsleeps and wakes. The clock gene can be used
to compare different organisms. The moreto compare different organisms. The more
similar the code is for the clock gene betweensimilar the code is for the clock gene between
two organisms, the more closely related the twotwo organisms, the more closely related the two
organisms are.organisms are.