Test 4- The Evidence for Evolution Flashcards
Evolution
Populations of organisms change over time
or
Any change in allele frequency in a population over time
Theory of Evolution
Life on Earth has changed gradually over time beginning with one primitive gene pool and through the process of natural selection has diversified into many forms including all that can be observed today.
Theory of Evolution in 5 short sentences
Life on Earth has:
- Changed
- Gradually over time
- beginning with one primitive gene pool
- and through the process of natural selection
- has diversified into many forms including all that can be observed today.
5 basic principles of The Theory of Evolution
- Evolution
- Gradualism
- Common Ancestry
- Natural Selection
- Speciation
Fossil Record
Evidence for Evolution
- Preserved evidence of past organisms in the strata of the Earth’s crust
- shows a distinct pattern of temporal succession
- Examples: bone, mineralized tissues, impressions
Where are fossils typically formed?
Sedimentary rock but also: -volcanic ash -amber -etc.
Relative dating of fossils
The deeper you go the older it gets
Core Layer Dating
- Dendrochronology
- Ice Cores
- Ocean Cores
- Coral growth strata
Radiometric dating
Radiocarbon dating (5,730 year half-life)
Uranium-Thorium (80,000 year half-life)
Potassium-Argon (1.3 billion year half-life)
Ardipithecus
Ardipithecus (Early Human) before Australopithecus 4.4 MYO
Archaeopteryx
Archaeopteryx (reptile-bird hybrid) feathers, teeth/beak, bony tail
Glossopteris
- Glossopteris (plant found along southern portion of Pangea)
- shows that the continents of South America, Africa, Asia, and Australia were once connected
Tiktaalik
Tiktaalik (Fish-Amphibian hybrid) flat head, eyes on top, wrist
-shows transition between fish and amphibian
Basilosaurus
-Basilosaurus (Marine Mammal) Hind fins
Australopithecus
Australopithecus (Early Human) 3.2 MYO
-Walked upright as shown through its 4th metatarsal in the foot
Biogeography
Evidence for Evolution
-The Study of the distribution of organisms on the planet
The way organisms are distributed consistently show what pattern?
a pattern of local adaptations and radiations to accessible areas (but not beyond)
ex. Australia and the distribution of marsupials
ex. Differences between oceanic and continental islands.
ex. Species rings (salamander in California thing)
Continental Islands
- Once connected to a continent but now separated
- ex. Madagascar, Japan, Great Britain
- Have full ecology containing all major groups comparable to the nearest continent
Oceanic Islands
- Formed from the seabed by volcanoes
- Ex. Hawaii, Galapagos
- Usually lack native freshwater fish, amphibians, reptiles, and mammals
- Often show diverse radiations of one type of organism
- ex. Darwin’s Finches
- Flightless birds are common, as are coconut trees
Comparative Anatomy
Evidence for Evolution
-The study and comparison of physical features
Homologous structures
-Show variations on a theme because these structures are inherited from a common ancestor
Comparative embryology
The similarities in many organisms in their embryonic stage
Vestigial structures
Structures that used to serve a function in the body of the organism but have become benign due to evolution.
ex. Kiwi bird having no wings
ex. Hairy tailed mole having under-developed eyes
Atavisms
DNA that is non-coding that occasionally gets turned on by mistake.
ex. Snake with atavistic leg
ex. dolphin with atavistic back fin
Comparative Biochemistry
Evidence for Evolution
- Genes (and thus proteins) are inherited and reflect a pattern of common ancestry
ex. Universal Genes showing variations on a theme
ex. Vestigial Genes
Olfactory Genes
odor detecting genes
examples
-Jawless fish have a few non-specialized odor detecting genes
-Bony fish have more genes and are adapted to odor detection in water
-Reptiles have even more genes and are adapted to odor detection in air
-Mammals have >1000 odor in air detection genes
Olfactory Genes and Vestigial Genes
examples
- Mice have >1000 working olfactory genes and a very acute sense of smell
- Humans have >1000 olfactory genes, but over half are vestigial (All primates show a trend: better color vision = more vestigial olfactory genes)
- Dolphins have >1000 olfactory genes and over 80% are vestigial
Genomic comparisons
Example of Comparative Biochemistry
Genetically species are similar to closely related species.
Modern observations of evolution
Evidence for Evolution Examples: -Antibiotic resistant bacteria -DDT resistant mosquitoes -Fish size in commercially fished species has become smaller -Humans on the Tibetal Plateau
Evidence for Evolution 5 examples
- Fossil Record
- Biogeography
- Comparative anatomy
- Comparative biochemistry
- Modern observations of evolution
5 basic principles of the Theory of Evolution
- Evolution
- Gradualism
- Common Ancestry
- Natural Selection
- Speciation
