Ch 13 evolution Evidence of change Flashcards
who was Charles Darwin
- Charles Darwin (1809-1892) contributed more to our understanding of evolution than any other scientist
- During his 5 year long voyage on the HMS Beagle Darwin spent many hours collecting, cataloging and studying organisms
- The vast diversity of life he saw lead him go question the origin of species
what are adaptations
Darwin thought that certain inherited traits would be better for the organisms survival
these would be called adaptations
what are structural adaptations
structural adaptations were physical traits
what are behavioural adaptations
Behavioural adaptations affect how the organisms acts
what are biochemical adaptations
Biochemical adaptations allow the organisms to do things like produce venom, and maintain homeostasis
what is fitness in an evolutionary sense
- Darwin thought the traits that allowed the organism to survive and reproduce would give the organism a fitness towards it’s environment
- creatures more fit to their environment were more likely to reproduce and pass on their traits
what is Darwins theory of common descent and speciation
- Darwin theorized that as species changed over time they become more and more distinct, and can form new species
- he though that all organism had evolved from others, and by tracing back evolution everything was related to a single universal common ancestor
which scientists helped prove the magnitude of geological time
- For the process of Evolution to produce the variety we see today an immense range of time is required to exist in earths past
- James Hutton observed the process that shaped the earth occurred very slowly and thought that therefor the earth must be very old to posses mountain, valleys, and other features
- Charles Lyell agreed and further evidence led them to argue the age of the earth and geological change
what are fossils
- Fossils are preserved remains of dead organisms found in sedimentary rock
- they form rarely so the fossil record is necessarily incomplete, and estimated 0.01% of organism are seen in the fossil record
- Fossils show change in organism and even climate
what process leads to fossil formation and discovery
- Dead Organisms can eventually get buried in sediment, the sediment turns to rock, and eventually the organic material can be replaced with mineral compounds, petrifying it, and in even rarer cases soft material are preserved
- Fossils can eventually reach the surface and they might be discovered by scientists, who might then reconstruct the organism, or otherwise use the fossil to learn about the long dead organism
what are palaeontologists
Palaeontologists are scientists that study the fossil record to see how organisms and environments have changed as well as to make a history of life.
what is relative dating
relative dating compares layers of rock to set the age of some deposits relative to others, but this is not process of give us the actual age.
what is radioactive dating
- Radioactive elements breakdown into new ones at a steady rate, each isotope has a half-life (the time for 1/2 of any sample of the atoms to decay) After 1HL you have 1/2, after 2HF you have 1/4, after 3HF you have 1/8, etc
- Knowing the half life of a particular isotope, using measurements we can calculate how many half-lines have passed and therefor the age of the sample
what are the four eons of earth’s history
Eon 1: The Hadean: 4.6-4 bya
Eon 2: The Archean: 4-2.5 bya
Eon 3: The Proterozoic: 2.5 bya-541 mya
Eon 4: The Phanerozoic: 541 mya-present
what are the three eras of the Phanerozoic
Era 1: The Palaeozoic: 541-252 mya
Era 2: The Mesozoic: 252-66 mya
Era 3: the Cenozoic: 66 mya - Present
what are the 6 periods of the paleozoic
Periode 1: The Cambrian: 541-485.4 mya
Periode 2: The Ordovician: 485.4-443.8 mya
Periode 3: The Silurian: 443.8-419.2 mya
Periode 4: The Devonian: 419.2-358.9 mya
Periode 5: The Carboniferous: 358.9-299 mya
Periode 6: The Permian: 299-252 mya
what are the two epochs of the Carboniferous
Epoch 1: The Mississippian: 358.9-323.2 mya
Epoch 2: The Pennsylvanian: 323.2-299 mya
what are the three periods of the mesozoic
Periode 1: The Triassic: 252-200 mya
Periode 2: The Jurassic: 200-145 mya
Periode 3: The Cretaceous: 145-66 mya
what are the three periods of the Cenozoic
Periode 1: Paleogene: 66-23.03 mya
Periode 2: Neogene: 23.03-2.58 mya
periods 3: Quaternary: 2.58 mya - Present
what are the three epochs of the Paleogene
Epoch 1: Paleocene: 66-55.8 mya
Epoch 2: Eocene: 55.8-33.9 mya
Epoch 3: Oligocene: 33.9-23.03 mya
what are the two epochs of the Neogene
Epoch 1: Miocene: 23.03-5.33 mya
Epoch 2: Pliocene: 5.33-2.58 mya
What are the two periods of the Quaternary
Epoch 1: Pleistocene: 2.58 mya - 11,650 ya
Epoch 2: Holocen: 11,650 ya - Present
what developmental evidence do we have for evolution
- the early embryos of many organism look very similar
- all vertebrates use the same gene group for the basic body plan (called the HOX cluster)
- As the embryo develops new and different genes change the organism to its species specific form
what are homologous structure
- structures in closely related organism, though suited to different functions, frequently have the same basic components
- Ex: all mammal limbs have the same basic parts
- Homologous structures show how structures were repurposed to new functions
