Chapter 8 Structured Notes Name:______Date:______Per:____
• Chapter 8.1 Change Over Time
– Differences Among Organisms
– Do Species Change Over Time
– Evidence of Evolution: The Fossil Record
• Fossils
• Reading the Fossil Record
• Gaps in the Fossil Record
• Vestigial Structures
– Case Study: Evolution of the Whale
– Evidence of Evolution: Comparing Organisms
• Comparing Skeletal Structures
• Comparing DNA from Different Species
• Comparing Embryonic Structures
Changes Over Time
Differences between species relate to adaptations.
______– a hereditary characteristic (attribute) that helps an organism survive and reproduce in its environment. Physical adaptations are ______. This means that the organism has no choice about the characteristics. Emotional, cultural, and behavioral adaptations are ______that humans can make.
It’s all about Species What is a Species?
– A ______of organisms that can mate with one another produces fertile offspring.
• Example: Horses, Donkeys, and Mules
– Breeding a male donkey to a female horse results in a ______;
– Breeding a male horse to a female donkey produces a ______
Do Species Change Over Time?
The Earth is very old – ______. The Earth was formed approx. ______
– The oldest rock is ______.
• ______suggests that species have changed over time because younger fossils are different, yet similar to older fossils giving rise to the idea of ______for all life on Earth.
• Evolution is the process by which populations of organisms acquire and pass on unique traits from generation to generation, affecting the overall makeup of the population and potentially leading to new species.
Geologic Time Notations
_____ – Years Ago _____ – Million of years ago _____ – Billion years ago
Precambrian Time ______Era ______ERA ______ERA
Era word roots ______use the clues in some of these words. For example:
– ______refers to animal life
– ______ means ancient
– ______means middle,
– ______means recent. So the relative order of the three youngest eras, first ______, then ______, then______, is straightforward.
Check for Understanding (True or False)
• ______ Scientists believe that all living things, including daisies, crocodiles, and humans, share a common ancestor.
• ______ A great number of species have died out since life first appeared on Earth.
• ______ The first mammals appeared on Earth at about the same time as the first terrestrial plants.
Evidence of Evolution: The Fossil Record
Fossils
Reading the Fossil Record
Gaps in the Fossil Record
Vestigial Structures
Fossils - Are found in the earth’s crust – the very uppermost part of the earth that is exposed to the surface or lying immediately below the oceans.
The best crust for fossils - ______are the best crust for fossil formations;
What are Fossils?
Fossils are the mineralized remains of animals or plants or other traces such as footprints.
______and their placement in rock formations and ______(strata) is known as the fossil record.
The study of fossils is called______.
What kind of rock is this?
Reading the Fossil Record
Law of Superposition: ______An undeformed sedimentary rock layer is ______than the layers above it and______than the layers below it
In terms of Relative Age
Rock Layer B must be younger than Rock Layer A
but
Rock Layer B is older than Rock Layers C and D.
Once the order of formation is known, a ______can be determined for each rock layer
Gaps in the Fossil Record
• Occur because specific conditions are needed for fossils to form
Organisms with hard body parts (skeletons) are more likely to form fossils than organisms with soft body parts. Basic to this is that organisms cannot be completely eaten before fossilization
– Why so many fossils are shells and bones.
• Fossils form best without oxygen – why peat bogs and tar pits have great fossils. Burial by sediments reduce oxygen exposure.
• Freezing also allows fossil formation – Mammoth that Japanese scientists are trying to clone from DNA extracted from frozen Mammoth fossil.
• Fossils once formed can be destroyed.
Check for Understanding
• Fossils found in the upper layers of the Earth’s crust are______than fossils found in the lower layers. (newer or older)
• There are gaps in the fossil record because
a. the conditions needed for fossils to form are rare.
b. very few different organisms have lived on Earth.
c. many fossils have been destroyed.
d. not many people are looking for fossils.
Vestigial Structures
• Mammals are warm blooded ______. Vertebrates are animals with ______. Vestigial structures are o______that have no apparent ______-.
• Examples:
– Human appendix – narrow tube attached to the large intestines
– Chimpanzee, gorilla, and orangutan have appendixes that are functional and used to help digest tough plant material
Whale evolution (terrestrial to aquatic in ~ 8 Myr)PBS Whale Evolution http://www.pbs.org/wgbh/evolution/library/03/4/l_034_05.html
Evidence of Evolution: Comparing Organisms
1. Comparing Skeletal Structures
2. Comparing DNA from Different Species
3. Comparing Embryonic Structures
Comparing Skeletal Structures
• ______: Having similar origins and anatomical patterns (homo - same
• ______: study of the structure of biological organisms
Homologous Structures
– Examples – bird wings, human arms, whale flippers, bat wings, cat legs.
Analogous Structures
• Analogous structures do the same thing – similar function, but different anatomy.
– Wings (butterfly external skeleton, bat internal skeleton
• Analogous structures: wing of an insect, bird, bat and pterosaur
Comparing DNA from Different Species
• DNA is a nucleic acid - a biological molecule called ______and is the ______of all organisms on earth.
• The actual molecular characteristics of DNA is measured and compared to other organisms.
• There are four different nucleotides in DNA (______, ______, ______, and ______).
• Gene sequencing – sections of DNA are sequenced for the order of nucleotide bases (ATCG or ATGC or ACTG, etc).
Looking for Relatedness
Comparing Embryonic Structures
• _______: Development of the Individual from conception to maturity.
• ______: study of evolutionary relatedness among various groups of organisms (e.g., species, populations)
• Vertebrate organisms (those having a backbone) have similar stages of life as an embryo
Check for Understanding
• All living organisms have the same type of ______
• All ______look very similar when they are in the embryonic stage. (living things or vertebrates)
Chapter 8.2 How Does Evolution Occur
• Charles Darwin
– Darwin’s Excellent Adventure
– Darwin’s Finches
– Darwin Does Some Thinking
– Darwin Learned from Farmers and Animal and Plant Breeders
– Darwin Learned from Geologists
– Darwin Learned from the Work of Thomas Malthaus
– Natural Selection
– More Evidence of Evolution (DNA Mutation)
Darwin
• Darwin’s father wanted Darwin to become a Doctor, but Darwin earned a degree in Theology instead. Theology is the study of ______. Later, Darwin was the naturalist on the HMS Beagle.
Darwin’s Excellent Adventure
• HMS Beagle – Galapagos Island Travels
• Galapagos Islands are part of the country of ______though the islands are about 1,000 kilometers west of the continent of ______in the ______. There are 19 ______with a land area of 8,000 km2 in an area of the Pacific Ocean over 60,000 km2
Darwin’s Finches
Diversity
• Darwin saw finches that were very different from each other as he traveled to the various islands of the Galapagos.
• Because of their______l differences (beak shapes), the finches had very different diets.
Darwin Does Some Thinking
• Darwin wonders how did the finches become so different. He thought maybe there was a storm that separated the original population resulting in geographic isolation (one of the ways that speciation can occur)
• Darwin’s hypothesis was that the Galápagos finches were descended from an original population of finches that was blown from South America to the Galápagos Islands.
Darwin Learned from Farmers and Animal and Plant Breeders
• Darwin was very familiar with ______or better known as selective breeding.
• Certain traits are determined by the breeder to be ______. If only those organisms with the favorable traits are bred then the trait will occur more often in the population. By isolated certain individuals the differences can grow. Example of dog diversity from an ancestral dog.
Darwin Learned from Geologists
• Darwin learned from Charles Lyell that the Earth was formed over a long period of time by natural process. This idea of geologic time (really-really long time ago) helped Darwin to more seriously consider natural processes for changing populations.
Darwin Learned from Thomas Malthus
• Thomas Malthus was an economist. Malthus reasoned that humans have the potential to reproduce beyond the capacity of their food supply.
• Malthus recognized that there are some limitations to human population growth:
– ______(for animals it is predation-predators)
– ______
– ______
Competition
• Because there are some limitations to growth, Darwin thought that those survivors must be better equipped (______) to their environment allowing them to out-compete other individuals.
• The offspring of the successful competitors have the same traits so are also more likely to survive in the same kind of environment.
Natural Selection
Darwin theorized that evolution occurs through a process he called natural selection
• ______– Each species produces more offspring that will naturally survive.
• ______– individuals will be slightly different from one another.
• ______– competition for resources Abiotic and Biotic factors
• ______– fitness – producing offspring (Survival of the fittest)
More Evidence of Evolution
• Darwin did not know what the mechanism was for how parents passed their traits to their offspring.
• ______l (1822-1884) the Catholic monk studied traits in sweet peas.
• With Mendel's work and biochemistry we now know that the mechanism is meiosis involving DNA that is subject to ______.
• Mutation - Changes to the heredity material- ______, deoxyribonucleic acid – result in a changed genotype of an organism .
• Some changes that occur are not observed because the change did not significantly affect a function. Changes that affect function result in a different ______(what things look or function like).
Chapter 8.3 Natural Selection in Action
• Insecticide Resistance
• Adaptation to Pollution
• Formation of New Species
• Separation
• Adaptation
• Division
Insecticide Resistance
• Insects that cause economic or health damage are becoming more difficult to kill due to insecticide resistances.
• Insecticides are compounds designed to kill insects (cidal – to kill).
• Insects that are resistant to a particular insecticide can survive and reproduce while those that do not have the genotype that infers resistance will die and will not reproduce.
Resistance
• The application of the harmful material (by humans) results in an artificial selection for those insects that are resistance.
• The same, unfortunately occurs to disease causing bacteria and virus, creating “super bugs” which often times results in incurable situations or death because antibiotics (against life) are no longer effective.
• This is why it is so important when prescribed an antibiotic to complete the treatment to avoid mutation during treatment of a pathogen creating a resistant pathogen that can survive – generation times of bacteria and virus is measured in minutes.
Adaptation to Pollution
• Peppered moths are the classic case.
• Dark moths were low in population because they did not blend well with the environment and so where eaten by predators. The pale moths were high in population because they were camouflaged.
• Then comes along the Industrial Revolution with coal burning to fuel factory machines and heat homes. The results of burning coal are sooty smoke, acid rain, and mercury contamination.
• Well, the sooty smoke coated the vegetation made those pale moths stand out like a sore thumb and the dark moths became camouflaged. So what do you think happened?
• The population of dark moths increased and the population of pale moths decreased.
Match each statement about the peppered moth population (1-4) with the appropriate step in natural selection (a-d).
Formation of New Species
Steps: Separation, Adaptation, Division (speciation).
• Separation allows the gene pool to be come isolated where no mixing of the populations occur.
• Adaptation are mutations that help the species to be successful in the new environment.
• Division occurs over time these mutant changes result in a separate species that cannot interbreed, speciation.
Chapter 8 Review
• One species evolves into another through the process of ______.
• A group of similar organisms that can mate with one another to produce fertile offspring is known as ______.
• A(n) ______helps an organism survive better it its environment.
• ______is the process by which populations change over time
• In ______, humans select traits that will be passed from one generation to another.
• A change in a gene at the DNA level is called a ______.
• The theory of evolution combines the principles of ______.
• The fact that all organisms have DNA as their genetic material is evidence that all organisms ______. Everything had to start somewhere.
Chapter 8 Notes 1