state standard sb5c. explain how fossil and biochemical evidence support the theory evidence of...
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State Standard
SB5C. Explain how fossil and biochemical evidence support the theory
Evidence of Evolution (15.2)
15.2 Evidence of Evolution
The Fossil Record
Evolution
Fossils provide a ____________ record of species that lived long ago.
Only the ____________ parts of an organism are likely to leave fossils – ex: shells, bones, thick cell walls.
Very few fossils capture the details of ____________ or internal ____________.
Sometimes ____________ are left behind in sediments along rivers and lakes.
Chapter 15
15.2 Evidence of Evolution
The Fossil Record cont’d
Evolution
Glyptodont
Fossils show that ancient species share ____________ with species that now live on Earth.
One problem w/ the fossil record is the lack of any “____________” or transition forms. This could be due to many organisms being too ____________ or due to fossils being ____________ by the erosion or pressure.
Armadillo
Chapter 15
15.2 Evidence of Evolution
Determining Fossil Age
Evolution
Biologists use ____________ dating to determine the approximate age of fossils.
The isotopes act as ____________ for measuring time. To use this method, scientists must know:
1. The ____________ of the isotope being measured.2. how much of the isotope was ____________ present in the fossil or in the rock containing the fossil.3. how much of the isotope is ____________..
Half-life is the amount of time it takes for half of the isotope to ____________.
Chapter 15
15.2 Evidence of Evolution
Determining Fossil Age Cont’d
Evolution
Biologists most often use ____________ for radioisotope dating, but its half-life is relatively ____________.
Other isotopes like Uraniaum 235 are often used to help determine the age of older fossils.
Relative dating determines the relative age of rocks/fossils by ____________ them to known older or younger layers.
Chapter 15
Evolution
Common ancestry can be seen in the complex metabolic ____________ that many different organisms share.
Comparative Biochemistry15.2 Evidence of Evolution
Chapter 15
Evolution
Comparisons of the similarities in these molecules across species reflect evolutionary ____________ seen in comparative anatomy and in the fossil record.
Organisms with closely related ____________ features have more closely related ____________ features.
15.2 Evidence of Evolution
Chapter 15
Comparative Biochemistry Cont’d
Evolution
Vertebrate ____________ exhibit homologous structures during certain phases of development but become totally ____________ structures in the adult forms.
Many scientists believe this is evidence that all vertebrates ____________ a common ____________.
Comparative Embryology
15.2 Evidence of Evolution
Chapter 15
EvolutionChapter 15
Anatomical Evidence
Homologous Structures
• ____________ similar structures that may or may not have the same ____________.
• Indicate possible ____________ ancestry
Evolution
Show that functionally similar features can evolve independently in __________ environments
Similar in function but __________ in __________ so they do not indicate shared ancestry
Chapter 15
Anatomical Evidence
Analogous Structures
Evolution
Anatomical Evidence
Vestigial Structures
Structures that are the ____________ forms of functional structures in other organisms.
Chapter 15
Evolutionary theorypredicts that features of ancestors that no longer have a function for that species will become ____________ over time until they
are lost.
Evolution
Anatomical Evidence
Adaptations
An adaptation is an ____________ trait that may increase an organism’s survival and reproductive success.
____________ is a measure of the relative contribution an individual trait makes to the next generation.
Chapter 15
Evolution
Camouflage Allows organisms to become almost ____________ to predators
All about ____________
Leafy sea dragon
Chapter 15
Anatomical Evidence
Adaptations Cont’d
Evolution
Mimicry One species evolves to ____________ another
species. All about ____________/warning (not hiding).
Western coral snake California kingsnake
Chapter 15
Anatomical Evidence
Adaptations Cont’d
Geographic Distribution
Evolution
The distribution of plants and animals that Darwin saw first suggested evolution to Darwin.
Rabbit Mara
15.2 Evidence of Evolution
Chapter 15
Geographic Distribution Cont’d
Evolution
The Mara & Rabbit fill the same ____________ on 2 different continents.
Darwin observed that the Mara was more ____________ to other South American species than it was to the rabbit, and vice versa.
Rabbit Mara
15.2 Evidence of Evolution
Chapter 15
15.2 Evidence of Evolution
Phylogenetic Trees
Evolution
A ____________ is a description of the line of descent of a group of organisms.
Fossil collections are often not ____________ enough to determine any evolutionary patterns or traits, so biologists will ____________ likely phylogenies by comparing morphological features, DNA sequences, and chromosomal characteristics.
____________ is the permanent loss of a species.
Chapter 15
Evolution
____________ traits are newly evolved features, such as feathers, that do not appear in the fossils of common ancestors.
____________ traits are more primitive features, such as teeth and tails, that do appear in ancestral forms.
Anatomically similar structures inherited from a common ancestor are called ____________ structures.
15.2 Evidence of Evolution
Chapter 15
Types of Characters (traits)
Cladogram - a diagram showing possible relationships between organisms based on shared traits (characters)
How to Read – if the organism is above the trait, it has the trait. If it is below the trait, it doesn’t have it.
Ancestral Character – shared by all species on the diagram.
Derived Character- only shared by some
Outgroup – least in common
Bat Wing
Human Arm
Homologous or Analogous?
Bat Wing Bird Wing
Homologous or Analogous?
Dragonfly WingHummingbird Wing
Homologous or Analogous?
Dragonfly WingBumblebee Wing
Homologous or Analogous?