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Flashcards in Into to Evolution and Biodiversity Deck (43)
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1
Q

What were the first experiments first carried out on pre-biotic synthesis? When did they take place and who by?

A
  • Heating of inorganic molecules such as H and ammonia in the absence of oxygen to generate a wide range of organic products e.g amino acids and sugar
  • 1953
  • Stanley Miller
2
Q

What happened 3.8 Billionyears ago?

A

chemicals + heat (lightning) formed organic molecules such as RNA + phospholipid like molecules which spontaneously organised into membranes

3
Q

What and when was the Cambrian explosion?

A
  • around 500 million years ago

- colonisation of land

4
Q

What happened during the Cambrian explosion?

A
  • consumption of O2 and generation of CO2
  • Massive explosion in the number of plants followed by massive loss (lacking CO2??) this formed fossil fuels
  • pangaea supercontinent formed
5
Q

What was the permian triassic extinction event (252 million years ago)?

A

The loss of around 95% marine species and around 70% land based vertebrate species and 83% insect genera
-Dinosaurs evolved from surfing species as well as birds and amphibians

6
Q

What caused the permian triassic extinction event?

A

meteor, volcanism, methane release, anoxia, high CO2

7
Q

When was the cretaceous-paleogene extinction event?

A

65 million years ago

8
Q

What caused the cretaceous-paleogene extinction event?

A

A huge asteroid hit the gulf of Mexico

9
Q

What were the impacts of the cretaceous-paleogene extinction event?

A
  • dust cloud blocked sunlight out for many years
  • acid rain
  • increased O2 conc (widespread fires)
  • 75% species became extinct
10
Q

What happened after the cretaceous-paleogene extinction event?

A

Large divergence into new forms and species within empty ecological niches

11
Q

What are the phases of human evolution?

A
  • Early (hominid) phase (largely ape-like)
  • Australopithecine phase (many species widespread in Africa, early tool use?)
  • Human (homo) phase, several species
12
Q

What happened in the homo phase?

A
  • global spread
  • encephalised
  • dietary range
  • behavioural complexity
13
Q

What did the Homo sapiens evolve from?

A

homo erectus

14
Q

What is the single-origin or ‘out of Africa’ hypothesis?

A
  1. Migration H.erectus out of Africa
  2. Speciation of H.sapiens out of H.erectus in Africa
  3. A further migration replacing the earlier dispersed H.erectus
15
Q

Who is Linnaeus and what did he do?

A
  • 18th century Swedish botanist
  • Created binomial nomenclature
  • Created Linnaean taxonomy (hierarchical rank classification)
  • Observation of evolution (grouping according to relation but had no mechanism to explain)
16
Q

What did Darwin observe on his trip on the Beagle from 1831-1836?

A
  • He noticed selective breeder (fancy pigeons descended from rock pigeon)
  • Biogeography-adaption to environment (finches and tortoises in Galapagos
17
Q

What 2 principles did Darwin discover?

A

1) all living things are connected - phylogenetic tree

2) A mechanism of selection drives change

18
Q

Describe the observations Darwin made when working out how a mechanism of selection drives change

A
  • Individuals in a population have many traits that can be heritable
  • Populations produce more offspring that can survive to produce offspring of their own
  • species are generally suited to their environment
19
Q

How does a mechanism of selection drive change?

A
  • Individuals whose traits are best suited to survive a given environment produce more offspring
  • As time goes on the favourable traits are accumulated in individuals
20
Q

What forms of evidence do we have that support the theory of evolution?

A
  • palaeontology
  • Biogeography
  • comparative embryology & embryology
  • Anatomical vestiges
  • biochem
  • endogenous retroviruses (ERVs)
  • microevolution
21
Q

How can palaeontology be used to support evolution?

A
  • fossil record (although can be incomplete) (and need to be carried out under exactly the right conditions)
  • transitional fossils (link two groups of organisms)
22
Q

How does biogeography drive evolution?

A
  • geographical isolation
  • continental drift
  • unique flora and fauna in Australasia
23
Q

How does cooperative embryology and anatomy support evolution?

A

-similar features indicative of a similar ancestor

24
Q

What are anatomical vestiges?

A

Features that date back to an ancestor that are non-functional but retained e.g tailbone

25
Q

How does biochem support evolution?

A

Common chemicals- amino acids, RNA, DNA

26
Q

What is DNA homology?

A
  • comparison of DNA sequences
  • level of homology correlated with evolutionary distance
  • pseudogenes
27
Q

What is microevolution?

A

evolution occurring now

e.g increased mosquito resistance to DTT and flu virus

28
Q

How do endogenous retroviruses help prove evolution?

A
  • remnants in the genome of retroviral infections which are similar to around 5% of the human genome
  • found at identical loci of different organisms
  • evolution from a common ancestor would explain this
29
Q

Why can evolution be bad?

A

-As we evolved quickly so can genetic disorders, meaning that they can arise more commonly and quickly before we have time to select against them
-Old genes exposed to 21st century lifestyle (more calories, less exercise, less vitamins etc)
(mismatch hypothesis)

30
Q

What is a model organism?

A
  • A non-human species studied to understand biological phenomena and provide insights into the workings of other organisms
  • in vivo models
31
Q

What are the difficulties of using a model organism?

A
  • Information has to be extrapolated from one organism to another
  • Ethical issues with using animals in experiments
32
Q

What can be used as a model organism?

A
  • prokaryotes (E.coli)
  • simple eukaryotes (yeasts)
  • Invertebrates
  • Vertebrates
  • Amphibians
  • Mammals
33
Q

What is an advantage + disadvantage of using prokaryotes as a model organism?

A
  • Can be grown and cultured easily and inexpensively in a lab
  • Significantly different to large eukaryotes
34
Q

What’s the advantages of using small eukaryotes as a model organism?

A
  • cheap and easy to grow

- Smaller genome than larger eukaryotes but share characteristics with larger organisms

35
Q

What are examples of invertebrates used as model organisms?

A
  • fruit fly

- nematode

36
Q

What is the nematode used for?

A

Understanding the genetic control of development and physiology because it has been completely sequenced

37
Q

Why is the zebrafish a good vertebrate to use for a model organism?

A

Can track stages of development because its body is nearly transparent in early stages

  • easily genetically manipulated
  • small and cheap
  • short generation time (lots of offspring)
  • must human genomes causing developmental diseases have a counterpart in zebrafish genome
  • can regenerate damaged parts of their heart
38
Q

Why are amphibians used as model organisms?

A

eggs and embryos used in development biology, cell biology and neuroscience
-large, easily manipulated embryos

39
Q

Why are mice used as model organisms?

A
  • many different strains that can be selected for particular interests
  • few differences between mice and humans
  • Small & easy to keep
  • mutations usually cause a similar phenotype
  • gene knockouts (null mice) provide information about genes and proteins
40
Q

Why do we need to keep biodiversity levels high?

A
  • need to have access to a wide variety of foods for nutrients for health
  • medicinal plant use (loss of biodiversity might limit new discoveries)
  • synthetic alternatives may not be available
41
Q

Why are non human primates good to use as model organisms?

A

-Strong similarities in physiology, behaviour, immunology and genetics

42
Q

What extinction event is happening now and why?

A

Holocene/anthropocene extinction event due to human activity

  • overpopulation
  • overconsumption
  • habitat destruction
43
Q

Why is climate change happening?

A

Due to increased levels of CH4 and CO2 in the atmosphere