5. Evolution and Biodiversity

• Central Concepts: Evolution is the result of genetic changes that occur in constantly changing environments. Over many generations, changes in the genetic make-up of populations may affect biodiversity through speciation and extinction.

• 5.1 Explain how evolution is demonstrated by evidence from the fossil record, comparative anatomy, genetics, molecular biology, and examples of natural selection.

Chapter 15-1 The Puzzle of Life’s Diversity

• 1809 _______________ – Father of Evolution. Naturalist from England. Sailed on the surveying ship HMS Beagle and traveled to various lands.

• During his travels, Darwin made numerous observations and collected evidence that led him to propose ______________________________ _______________________________________.

Darwin’s Observations       ______________________ – organisms seemed well suited

to their environment! There were SO many different types of similar organisms (68 different types of beetles in the Brazilian rainforest).  Was there such way that leads to variety. Why were certain types or organisms only found in certain areas? How were they so well suited for their environment?

      ______________________ – Darwin collected the preserved remains of ancient organisms from many places (fossils). Why have so many species disappeared and how were they related to living things.

      ______________________ – One of the most influential places - off the coast of S. America. They were close together – they have very different climates very different organisms (from hot, dry nearly barren; lots of plants few plants).

  __________ – 16 different types of birds – differed in color and beak shape (based on what they ate. o  ___________ – varied from one island to another. Darwin observed that the characteristics of many animals and plants varied noticeably among the different islands of the Galapagos

15-3 Darwin Presents His Case • Darwin put his thoughts and evidences into a book (title above).• Inherited variation and artificial selection• __________________________ – nature provided variation, and human

selected those variations that they found useful. Horse/dog breeders; farm animals (breed the best ones – not the worst)

• __________________________ – process by which individuals that are better suited to their environment survive and reproduce most successfully (survival of the fittest)

      Fitness – _______________________________________       Adaptation – ___________________________________• _____________________________________________________.       Descent with modification – ________________________• _____________________________________________________, establish

different niches, or occupy different habitats. (that’s why they look different from their ancestors)

___________________________________________

• Darwin argued that living things have been evolving on earth for millions of years.

FOSSILS

• __________________________________

• fossils lower in rocks and mountains are older than those in higher areas. They also show that organisms changed a LOT over time. Gaps remain in the fossil record.

HOMOLOGOUS BODY STRUCTURES

_______________________________

__________________________________. Comparative Anatomy: Provide evidence that all four-limbed vertebrates have descended with modifications from common ancestors.

VESTIGIAL ORGANS

• ___________________________________

• ___________________________________

• ___________________________________.  It may not affect an organisms ability to survive and reproduce, so natural selection did not eliminate the organ

EMBRYOLOGY

_______________________________

_________________________________________________________________

4 Evidences for Evolution

• 1_______________________________

• 2_______________________________

• 3_______________________________

• 4_______________________________

DARWINS THEORY

1. Individual organisms differ, some variation is heritable

2. organisms produce more organisms than survive

3. Organisms compete for limited resources 4. Most fit organisms survive 5. species alive today are descended with

modification

• Paleontologists: _______________________________________________________• The fossil record provides evidence about

the history of life on Earth. It also shows how different groups of organisms, including species, have changed over time.

• ____________ of anything that was ever living on this earth is now extinct.

17-1 The Fossil Record

• Most fossils form in ________________ ________, as shown in the figure at right. Sedimentary rock is formed when exposure to rain, heat, wind, and cold breaks down existing rock into small particles of sand, silt, and clay.

• In __________________________, the age of a fossil is determined by comparing its placement with that of fossils in other layers of rock, as shown in the figure at right. Recall that sedimentary rock is formed from the gradual deposition of layers of sand, rock, and other types of sediment. The rock layers form in order by age—the oldest layers on the bottom, with more recent layers on top, closer to Earth's surface.

• Relative dating allows paleontologists to estimate a fossil's age compared with that of other fossils.

• 5.2 Describe species as reproductively distinct groups of organisms. Recognize that species are further classified into a hierarchical taxonomic system (kingdom, phylum, class, order, family, genus, species) based on morphological, behavioral, and molecular similarities. Describe the role that geographic isolation can play in speciation.

SECTION 18-1 Finding Order in Diversity

• SCIENTISTS HAVE IDENTIFIED MORE THAN ____________ _______________________ OF ORGANISMS ON EARTH, BUT ESTIMATE 40 MILLION SPECIES INHABIT THE EARTH.

        A Universal System is necessary to have clear communication among scientists worldwide. A system that required an International System for Classifying and Naming all organisms.

        2,000 years ago Greek philosopher ___________________ classified things as either Plant or Animal and then as land dwellers, water dwellers and animal dwellers.

      Scientists found that Using __________________________, such as robin or fir tree, for an organism presented its own problems; common names varied from on locale to the next and common Names May Not describe species accurately.

        __________________________ in the mid-1700s, Swedish Biologist established a simple system for classifying and naming organisms (taxology). He developed a Hierarchy for classifying organisms based on __________________________ (using what it looks like to categorize it)

Today we have SEVEN LEVELS OF CLASSIFICATION: 

•     A. __________________  (largest classification)    B. __________________     C. __________________     D. __________________     E. __________________     F. __________________     G. __________________  (smallest classification)

KING PHILIP CAME OVER FOR GRAPE SODA.  

   __________________________________ is a 2 name system based on the organims’s genus and species.

•  • SAMPLE:  Acer rubrum - RED MAPLE TREE •     Acer is the Latin name for Maple (genus) •     rubrum is the Latin word for Red (species) •     OR THE NAME CAN BE ABBREVIATED AS:

           A. rubrum. •     HUMANS ARE NAMED: Homo sapiens •     Homo because of our large brain and upright posture.

    sapiens because of our intelligence and ability to speak.

CHAPTER 18-2 Modern Evolutionary Classification

• When placing an organism into a Taxonomic Category, Modern Taxonomists May consider its:

    • _______________________ (what it looks like)

    • _______________________

    • ______________________________________

    • _______________________

    • _____________________________________  

SECTION 18-3, Kingdoms and Domains

Currently we have a 6 kingdom classification system

• THE SIX-KINGDOM SYSTEM

• 5.3 Explain how evolution through natural selection can result in changes in biodiversity through the increase or decrease of genetic diversity within a population.

16-3 The process of speciation• Factors such as natural selection and

chance events can change the relative frequencies of alleles in a population. But how do these changes lead to the formation of new species, or speciation?

• NATURAL SELECTION:

ISOLATING MECHANISMS:1. ______________________________: As new species evolve,

populations become reproductively isolated from each other and can no longer produce fertile offspring.

2. ______________________________: when two populations are capable of interbreeding, but have differences in courtship rituals or reproductive strategies that involve behavior.

3. ______________________________: two populations are separated by geographic barriers such as rivers, mountains or bodies of water.

4. ______________________________: two or more species reproduce at different times.

17-4PATTERNS OF EVOLUTION

• PATTERNS OF EVOLUTION

• Six important topics in macroevolution are 1. ____________________________: 99.9% of all species ever on this

earth are now extinct. Mass extinction. (most extinctions today are due to human activity)

2. ____________________________: a single species or small group have evolved into different forms that live in different ways. Ex. FINCHES, homologous structures

3. ___________________________________: Unrelated organism come to resemble one another. Ex. Dolphin/sharks

4. _________________________: process by which 2 species are closely connected to one another by ecological interactions evolve together. Ex. Plants and plant eating insects

5. ____________________________: some groups of organism have evolved rapidly after a mass extinction