CHAPTER 7 Evidences of Evolution Flashcards
Evidence of Evolution
- Fossils and fossil records
- Comparative Analysis (Homologies)
- Biochemical evidences
- Observable events
* Distribution in time and space
Evidence of Evolution
- provides snapshots of the past that, when assembled, illustrates a panorama of evolutionary change over the past four billion years.
fossil record
Evidence of Evolution
- is any evidence of ancient life with an age limit which of 10,000 years old; usually found in sedimentary rocks
2 Main Types:
a. Direct Fossils = termed as ‘—’ such as bones
b. Indirect Fossils = termed as ‘—’ such as traces of plants
and coprolites or fossilized ‘poop’ or feces
fossil
remains
imprints
Significance of Fossil
1. -E
2. -C
3. -D
4. -W
5. -T
* Archaeopteryx: between reptiles & birds
* — amphibious fish
* — reptile-like amphibian
* Also, mammal-like reptiles & whales with hind limbs
- Extinction of species
- Reveals ancient climate & environmental conditions
3.Indicates development of life from simple to complex
4.Indicates life began in water - Transitional forms reveal links between groups:
* Eustheopteron
* Seymouria
Reveals ancient climate & environmental conditions
typically, plants in warmer climates have larger leaves with smoother edges, while plants in cooler climates have smaller leaves with more jagged edges
A strange worm-like animal, was covered in spikes, likely as
protection against these voracious predators.
Hallucigenia
is a worm-like animal, bearing ten pairs of clawed, spiny limbs on the lower part of its body. The animal had a soft, flexible, non-mineralized cuticle, which had a corrugated, accordion-like form. A suite of claws also adorned the end of each stub-foot. A faint line running down the axis of the organism is interpreted as its gut
Aysheaia
has a wide head shield with six pairs of head appendages projecting forward that are segmented and branch into two (biramous).
Sanctacaris
looks like trilobites
Olenoides
A creature smaller than a human’s thumb, is thought to be closely related to the ancestor of all vertebrates.
Pikaia
A predatory species, displaying five eyes and a strange proboscis used to capture its prey
Opabinia
Large arthropods; considered as the top predator hunting on
trilobites (olenoides) and other invertebrates
Anomalocaris
Tetrapod in the Devonian period where their fins represented the archaic beginnings of what would become our own arms and five-fingered hands.
Eustheopteron
- A group of Permo - Carboniferousreptiliomorphs with both terrestrialand aquatic taxa.
- Reptile-like amphibian
Seymouria
Direct Fossils
- This are true fossils parts of early organisms
- Entire organism frozen in ice
- Minerals replace hard parts (bones, teeth, etc.) of organism
- Entire organism fossilized in tree sap
- remnants
- frozen
- petrification
- amber
Indirect Fossils
- (thin, soft object (leaf, feather) is buried and sediments later harden)
- Buried organism disappears and leaves an empty space
- Mold filled by minerals (replica of organism)
- Traces of the organism; provides information on how organism lived, hunted, food pref., etc
- imprint
- mold
- cast
- trace
How can fossil age be determined?
- Depth of fossils help to determine their age
- Lower layers are ____ than those in upper layers
- Radioactive Isotope Dating
- -
- Measure the proportion of an
isotope relative to its more
stable form (half life)
older
Carbon-14, Uranium-238,
Potassium-40
Why is the fossil record incomplete?
RP
CH FC
MC
NDU
- Soft tissue rarely preserved
- Fossilization takes place only in certain types of habitats and under favorable
conditions
- Fossilization takes place only in certain types of habitats and under favorable
- Movement of the earth’s crust has obliterated or covered many fossils
- Paleontologists have not dug up every place on earth
Evidence of Evolution
Study of anatomical structures to find similarities
and differences
* HOMOLOGOUS STRUCTURES – parts with similar basic
structure (derived from same structures in embryo—
same common descent), but may vary in function
Comparative Anatomy
– structures that have the same function
(may look somewhat alike), but have different structures and DO NOT have a common descent
ANALOGOUS STRUCTURES
ex. wings of bat and bird
reduced body parts (in comparison to
the same complex structure in other organisms) that have little to no function; remnant of an ancestor
give examples
VESTIGAL STRUCTURES
- Human appendix (other mammals it is necessary to aid in digestion)
- Human external ear muscle
- Human tailbone (coccyx)
- Human wisdom teeth
- Bird wings – Penguins adapted for swimming, ostrich wings for balance and courtship
Patterns of embryological development can indicate a common ancestry
embryology
- Fish, birds, mammals & reptiles all have gills; only fish retain theirs
- Fish, birds, humans & reptiles all have tails; ALL but humans retain theirs
Biochemical Similarities & Evidences
- Similarity of proteins, RNA & DNA molecules
- The more closely related organisms are, the —
- Indicates common ancestor
- — – supports evolution
- Similar chemistry & structure of chromosomes among Eukaryotes
- — is the same basic molecule in all photosynthetic organisms
more similar is the biochemical makeup
Universality of genetic code
Chlorophyll
