310 likes | 326 Views
EVOLUTION. Today ’ s agenda :. UNIT 4 - Evolution. LT 4.1 I can communicate scientific information that common ancestry and biological evolution are supported by multiple lines of empirical evidence. Did we come from monkeys?. Prior knowledge.
E N D
EVOLUTION Today’s agenda:
UNIT 4 - Evolution LT 4.1 I can communicate scientific information that common ancestry and biological evolution are supported by multiple lines of empirical evidence
Prior knowledge • Write down two things you know about evolution and one question you have
Evolution Evolution is the process of biological change by which descendants come to differ from their ancestors. What are ancestors? What are descendants?
Evolution of dance https://www.youtube.com/watch?v=dMH0bHeiRNg
Fossil • Embryology • Anatomy • Molecular Biology Stations
Evidence supporting evolution 1. Fossil record • shows change over time 2. Embryology 3. Anatomy • homology & vestigial structures • embryology & development 4. Molecular record • comparing protein & DNA sequences
1. Fossil record Layers of rocks contain fossils • new layers cover older ones and create a record over time • fossils show a series of organisms that have lived on Earth over a long period of time http://www.youtube.com/watch?v=3rkGu0BItKM
Different organisms show similar embryonic developmental characteristics 2. Embryology
Embryology • Development of embryo tells an evolutionary story • similar structures during development all vertebrate embryos have a “gill pouch” at one stage of development
How could thesevery different animalshave the same bones? 3. Anatomy: homologous structures • Homologous structures are similar in structure but may have different in function. • Limbs that perform different functions are built from the same bones • Evidence of a common ancestor!
Analogous structures • look similar • on the outside • same function • different structure & development • on the inside • different origin • no evolutionary relationship Analogous structures How is a birdlike a bug? Solving a similar problem with a similar solution
Bat wing Fly wing Analogous structures: example Why is this an example of analogous structures?
Vestigial organs • Vestigial structures are remnants of organs or structures that had a function in an early ancestor. • Ostrich wings and the human appendix are examples of vestigial structures http://www.youtube.com/watch?v=s2c8k_uYh6o
For each vestigial structure in the table hypothesize what its function may have been
4. Molecular/Biochemical Evidence • DNA used to translate nucleotide sequences into amino acid is essentially the same in all organisms • Powerful argument in favor of the common descent of the most diverse organisms.
Molecular evidence: example • Cytochrome c (a protein involved in cellular respiration) • Amino acid sequence to make cytochrome c differs increasingly the more distantly related two organisms are (very similar amino acid sequence = closely related) • The cytochrome c of humans and chimpanzees is identical
Check your understanding Some organisms that share a common ancestor have features that have different functions, but similar structures. These are known as 1. vestigial structures 2. analogous structures 3. homologous structures 4. fossil structures
Check your understanding If an organism has a vestigial structure, that structure likely once had a function in a(n) 1. close relative 2. early ancestor 3. unrelated organism 4. embryological stage
Check your understanding What term describes features that are similar in structure but different in function? 1. analogous structures 2. vestigial structures 3. comparative structures 4. homologous structures
Check your understanding In which rock layer would you expect to find the most primitive fossils? 1. top layer 2. middle layer 3. bottom layer 4. rock layers that have been uplifted by earthquakes
Check your understanding Which of the following is not a source of evidence of evolution? 1. Adaptation 2. fossils 3. anatomy 4. embryology
Check your understanding Which of the following are analogous structures? 1. human hand and bat wing 2. bird wing and insect wing 3. human appendix and cow cecum 4. seal flipper and bird wing