Lecture 16 - Evolution after Darwin Flashcards
What was Darwin’s last book? And what was it about?
The formation of vegetable mould, through the actions of worms, with observations on their habits (1881)
Found that worm reshaped the landscape of Earth and helped to fertilise the soil
Concluded that worms cannot hear – they react to vibrations
What is the function of wormstone? What did it prove?
measure the rate that it gradually sunk into the earth (slow and gradual process)
Proved that things are constantly buried by earthworms
What is the meaning of Pangenesis?
Cells flow through your body – pass down characteristics from the adult to the offspring
When was Darwin’s statue placed inside London’s Natural History Museum?
1885
Who was the first person to introduce rigorous statistical methods to study heredity?
Francis Galton
Who coined the term Eugenics and when was it coined?
Francis Galton in 1883
What was August Weissman’s Germ plasm theory about?
Only the characteristics of the sex cells get passed) not passed down by any particle that is flowing through the body
Inheritance (in a multicellular organism) only goes through germ cells: egg cells and sperm cells, not body cells.
No inheritance of acquired characteristics (anti-Lamarckism)
Characteristics are in the reproductive cells (gametes)
Is Gregor Mendel the father of modern genetics?
Nope
What was Carl Linnaeus thought about how species are formed?
He thought that species were formed/evolved due to cross-breeding between varieties (Not by natural selection as proposed by Darwin)
What did Gregor Mendel conduct experiment on and what was he trying to study?
Pea plants
Wanted to show that speciation is a result of hybridisation, conducted experiment to study hybridity and inheritance in pea plants.
What was the finding of Gregor Mendel’s pea plant experiment?
The 3:1 ratio
What are Mendel’s 2 laws?
Law of Segregation
Law of Independent assortment (different traits are inherited independently of each other)
What law did Gregor Mendel create?
“Law of combination of different characters” but only specified to hybrids
Did Darwin have a copy of Gregor Mendel’s work?
Nope
What did Hugo de Vries postulate?
Postulated that “inheritance of specific traits in organisms comes in particles” which he called “pangenes”
Combined Galton’s statistics to create a new theory – theory of mutation (mechanism where organisms become different without natural selection)
Who were the founder of modern genetics?
Hugo de Vries, Carl Correns and Erich von Tschermak
What did Walter Sutton and Theodor Boveri suggest?
They suggested that chromosomes are hereditary units
What did Thomas Hunt Morgan want to prove?
Morgan sought to prove Mutation Theory with his experiments breeding fruit flies
1910 Morgan showed that genes are on chromosomes
1915 Morgan combined Mendel’s theories with Chromosome Theory of Inheritance.
Wanted to prove that mutation was responsible for the variation in living things, not natural selection (but was proven wrong)
What did Ernest Rutherford discover?
Discovered radiometric dating – used radioactivity to date rocks
Who discovered the double helix structure of DNA?
James Watson and Francis Crick
What is the modern synthesis?
genetics confirmed evolution by natural selection.
Mutation was a major source which natural selection picks to adapt things. One of the ways where variations occur
Majority of variation in organisms is a result of sexual reproduction, not mutation
Genetics was part of natural selection
Who proposed the theory of Continental Drift?
Alfred Wegener
He had evidence, the rocks of either side of the ocean were identical rocks. They contained exactly fossil types. (cannot be a coincidence) evidence that they originated from the same spot.
What is Palaeomagnetism?
The reversal of Earth’s magnetic field.
Evidence of seafloor spreading?
Magnetic Striping
