Blueprint of Life Flashcards
1
Q
Macro- evolution
A
Millions of years, arising new species. E.g wolf and dog from common ancestor
2
Q
Micro- evolution
A
Shorter time periods, pop changes but no new species. E.g. Different dog breeds
3
Q
Changes in physical conditions in the environment
A
- Early living organisms from water to land habitats→ reduced UV radiation as result of ozone forming
- Aus climate from cool, wet to hot, dry→ rain forest to woodland (changes in animal life)
- Aus lakes dry up→ evolution of plants and animals conserve water
- Fire influence→ fire resistant species
- Dust clouds;meteorite→ reduced light, plant life reduced→ dinosaurs lack food (extinct)
- Ice age→ Changes in sea levels, temp
4
Q
Changes in chemical conditions in the environment
A
- First life forms→ anoxic environment; some produced CO2 from metabolism→ led to emergence of photosynthetic organisms
- Increased oxygen levels→ evolution of organisms that use oxygen in respiratory pathways (complex, diverse→ animals today)
- Peppered moth→ Industrial revolution. Black moths now protected from black soot on trees, White moths now stand out and are eaten (previously black stood out on white trees)
5
Q
Competition for resources
A
- Competition for light, soil nutrients, water, shelter, mates, breeding territory
- Change in pop environment→ influences evolution (selective pressure acts on organism)
- Organisms compete, most successful survives to breed, passes on genes for next generation
- Compete successfully in new environment outlive those without variations.
6
Q
Plan, choose equipment or resources and perform a first-hand investigation to model natural selection
A
- Pop begins with 30 moths (10 black, 10 grey, 10 white) → use chart to work out offspring colours
- Each year work our predation using spinner (colour chosen is removed)
- Shuffle cards and repeat process for each year until recognisable trend in populations of each colour
- At end of 4 years→ observe differing number of surviving moth colours. Is there dominant species?
7
Q
Analyse information from secondary sources to prepare a case study to show how an environmental change can lead to changes in species (SNOW GUM)
A
HIGH ALTITUDE
- Cold, shallow soil, exposed to snow
- Small and twisted to bend away from elements.
- Short leaves
- Large fruit
- Thin bark
- More resistance to frost
- Short trees
LOW ALTITUDE
- Warm, high precipitation,
- Tall and straight to receive nutrients and rainfall
- Long leaves
- Small fruit
- Thick bark
- Less resistance to frost
- Tall trees
8
Q
Palaeontology
A
- Scientific study of fossils and extinct life
- Predictions; fossils in undisturbed rock show sequence living things arose in, and fossils have features in common representing changes in organisms over long periods of time
- E.g. Lobe finned fish→ bones in fins allow dragging from water to land. (Ancestral limb of terrestrial vertebrates. ) Amphibians evolved from fish → features from fish and amphibian forms
- Limitations: fossil record incomplete, bas towards fossils with body or environment better suited to being fossilised. Radiocarbon only can date from 50,000 years→ correct age sequencing unknown
- Fossils give evidence of past life forms→ reflects evolutionary transitions to modern living forms
9
Q
Biogeography
A
- Study of geological distributions of organisms both living and extinct
- Darwin/Wallace theory→ for new species, group of individuals must be isolated from rest.
- Prediction; Species will be similar to species living close by, than to species found far away
- E.g. Flightless birds (ratites) and continental drift→ common ancestor at Gondwana, different pop evolved on isolated southern continents before drift apart. Aus→ emus, NZ→ Kiwi, Sth Africa→ Ostrich, Sth America→ Rheas (all share similar features→ flat breastbone)
- Limitations; comparisons only for species that have become isolated at some point
10
Q
Comparative embryology
A
- Comparison of similarities in very early embryos of vertebrates (similarities suggest common ancestors)
- E.g. Fish, amphibians, birds, mammals, reptile embryos→ gill slits, tails in early embryo (later develop into Eustachian tube in mammals and internal gills in fish)
- Embryos of closely related organisms have homologous parts→ support common ancestor
11
Q
Comparative anatomy
A
- Study of similarities in structures of organisms, determines evolutionary relatedness (similarities suggest common ancestor, differences represent modifications→ how much evolution to be different)
- E.g. Pentadactyl limb (homologous structure→ forelimb) same basic sequence of bones in dog, bat, bird, human etc→ Humerus, ulna and radius, carpal
- Limitations; fossils often incomplete→ hard to compare with extinct life form
- More similarities in structure→ more closely related
12
Q
Biochemistry
A
- DNA hybridisation: Compare DNA sequence of 2 organisms→ unzip and zip codes to match sequencing
- E.g. Heat applied to chimpanzee and human DNA→ high temp means more closely related. 83℃
- Amino acid sequencing: Proteins from species obtained, similarities in sequencing analysed
- E.g. Chimps and humans have identical amino acid sequence in haemoglobin. More related than humans and gibbons (3 differences)
- Similarities→ may have shared common ancestor. Differences→ organism evolved over time
- Limitations: techniques complex, expensive, only performed in high tech lab
13
Q
Person a first-hand investigation or gather information from secondary sources (including photographs/diagrams/models) to observe, analyse and compare the structure of a range of vertebrate forelimbs
A
Humerus Radius Ulna Carpals Metacarpals Phalanges
14
Q
Use available evidence to analyse using a named example, how advances in technology have changed scientific thinking about evolutionary relationships (CLASSIFICATION OF PRIMATES CHANGED)
A
- DNA from amino acid sequencing, DNA hybridisation, DNA sequencing→ new biochemical evidence (change how apes are classified)
- Historically→ Orangutans, gorillas, chimps classed as one family→ humans different family (based off structure of hind leg, tooth enamel)
- 1960’s→ identical sequences of haemoglobin and cytochrome c in chimps and humans→ but different to gorillas
- Technologies proved humans and chimps have small difference in DNA and gorillas and chimps more closely related to humans than orangutans (diverged earlier)
- Data established new genetic tree→ humans, chimps diverged more recently from common ancestor, gorillas diverged earlier and orangutans are sister species to these groups (diverged much earlier)
15
Q
Explain how Darwin/Wallace’s theory of evolution by natural selection and isolation accounts for divergent evolution and convergent evolution
A
- Darwin/ Wallace independently develop idea f on mechanism of evolution (natural selection) then publish together. Theory proposed:
- Variations within population of species
- In population, more offspring produced than can survive and reproduce
- Some individuals have adaptive characteristics, enable survival and reproduce better
- Adaptive characteristics passed to next generation→ increased proportion with advantage
- Over time, result of natural selection is pop with adaptations more suited to environment
- Theory of evolution; competition & environmental pressures naturally select best adapted individuals
- Natural selection→ Doesn’t explain how new species could be generated
- Source of variation in organisms→ gene mutation confers phenotypic advantage
- Isolation→ if pop of species is geographically isolated and interbreeding stopped → 2 separate species develop)
- Divergent evolution: One species forms many others with adaptations suited to variety of environments. E.g. Australian marsupials evolved from common possum like ancestral species (common structural similarities, but differences are dominant)
- Convergent evolution: Organisms come to resemble each other from sharing similar environment and performing same function. Once isolated, organisms continue to evolve become better suited to environment. E.g. Streamline body of dolphin, shark for swimming in sea . Look similar but shark- fish, dolphin- mammal.
