Genetics, Evolution & Behaviour
Introduction Part 1
Charles Darwin – Shrewsbury School - HMS Beagle 2 – Galapagos Trip
‘Survival Of The Fittest’ – Alfred Wallace
Erasmus Darwin – Grandad – came from a common ancestor.
Taxonomy – Carl Linnaeus
200 years – science influenced by religion – Vatican, Catholic. Church of England ,
thought that Life was created at the same time by God.
Believed that the form of each type of organism was in a permanently fixed state.
No variation, was how it was created.
When this began to be challenged.
o Industrial Revolution – Excavation finds of fossils, unusual rocks, teeth, bones,
whole organisms. And they didn’t resemble any of the creatures of earth –
Dinosaurs.
o Certain Fossils were always in the same rock layers – die to age and compression .
Not ways the case due to tectonic movement.
o Lowers layers – Simple creatures – Trilobite, seed ferns, Dinosaur.
o Higher layers were more complex creatures.
o Mary Anning – Palaeontologist/ fossil collector. Came from a large family . Went
digging on the south coast – white cliffs of dover. Geology.
How are these fossil findings explained
Georges Cuvier – Catastrophism Theory – Biblical floods, natural disasters
These catastrophes produced the layers of rocks and killed species – still taking
into account the biblical element.
He was not wrong as there were major extinction events in history…. But why did
it only kill certain species and not modern species. Modern species have not been
found in the lower and middle layers.
Jean Baptiste Lamark – Frech
Biologist
Noted that older Fossils were
simpler and younger ones were
more complex.
Lamarks theory (1801)
‘inheritance of acquired
characteristics’
, Charles Darwin
o 1859 – On the Origin of Species
o Decent with Modification
Lamark = Variation is acquired – within the
species – variation over their life. Giraffe neck
becomes longer based on the environment.
Interaction with the environment.
Darwin = Variation Is Inherited – take away the
idea of purpose and bring in the idea of chance.
Suitability to the environment thrive. They then
reproduce and pass on the trait that is suitable.
Eg the long neck. ‘Survival of the fittest’.
Alternative explanation for long necks in the giraffe:
Might not be due to selection pressure to reach vegetation, but due to sexual selection
on female choice – males use their necks to fight to compete for females.
HMS BEAGLE 2 SURVEY
o South AMERICAN Coast + Galapagos Island
o Surprised at the Diversity of plants and Animals in the different environment. Far
more diverse than Europe.
o He started to doubt the permanence of species – Snakes with Rudimentary hind
limbs, snakes that shake their tails but they don’t rattle, Flightless birds (penguins
– use wings to paddle in the water) (birds use wings for mating rituals not flying)
o Darwin’s Finches – endless numbers – were very different but had similar qualities.
Had a variation in their beak shape. This was related to their feeding habits.
o Heavy set beaks – seeds and nuts use beaks to crush nuts
o Light beaks – Insects - use small beak to get into places
o Most animals reproduce more rapidly than humas, but their populations do not
grow unchecked (there is control) Not all animals reproduce and vast numbers
die.
o Individuals of species differ from one to another in form and function.
Evolution By Natural Selection
Which individuals die in each generation is not arbitrary
Introduction Part 1
Charles Darwin – Shrewsbury School - HMS Beagle 2 – Galapagos Trip
‘Survival Of The Fittest’ – Alfred Wallace
Erasmus Darwin – Grandad – came from a common ancestor.
Taxonomy – Carl Linnaeus
200 years – science influenced by religion – Vatican, Catholic. Church of England ,
thought that Life was created at the same time by God.
Believed that the form of each type of organism was in a permanently fixed state.
No variation, was how it was created.
When this began to be challenged.
o Industrial Revolution – Excavation finds of fossils, unusual rocks, teeth, bones,
whole organisms. And they didn’t resemble any of the creatures of earth –
Dinosaurs.
o Certain Fossils were always in the same rock layers – die to age and compression .
Not ways the case due to tectonic movement.
o Lowers layers – Simple creatures – Trilobite, seed ferns, Dinosaur.
o Higher layers were more complex creatures.
o Mary Anning – Palaeontologist/ fossil collector. Came from a large family . Went
digging on the south coast – white cliffs of dover. Geology.
How are these fossil findings explained
Georges Cuvier – Catastrophism Theory – Biblical floods, natural disasters
These catastrophes produced the layers of rocks and killed species – still taking
into account the biblical element.
He was not wrong as there were major extinction events in history…. But why did
it only kill certain species and not modern species. Modern species have not been
found in the lower and middle layers.
Jean Baptiste Lamark – Frech
Biologist
Noted that older Fossils were
simpler and younger ones were
more complex.
Lamarks theory (1801)
‘inheritance of acquired
characteristics’
, Charles Darwin
o 1859 – On the Origin of Species
o Decent with Modification
Lamark = Variation is acquired – within the
species – variation over their life. Giraffe neck
becomes longer based on the environment.
Interaction with the environment.
Darwin = Variation Is Inherited – take away the
idea of purpose and bring in the idea of chance.
Suitability to the environment thrive. They then
reproduce and pass on the trait that is suitable.
Eg the long neck. ‘Survival of the fittest’.
Alternative explanation for long necks in the giraffe:
Might not be due to selection pressure to reach vegetation, but due to sexual selection
on female choice – males use their necks to fight to compete for females.
HMS BEAGLE 2 SURVEY
o South AMERICAN Coast + Galapagos Island
o Surprised at the Diversity of plants and Animals in the different environment. Far
more diverse than Europe.
o He started to doubt the permanence of species – Snakes with Rudimentary hind
limbs, snakes that shake their tails but they don’t rattle, Flightless birds (penguins
– use wings to paddle in the water) (birds use wings for mating rituals not flying)
o Darwin’s Finches – endless numbers – were very different but had similar qualities.
Had a variation in their beak shape. This was related to their feeding habits.
o Heavy set beaks – seeds and nuts use beaks to crush nuts
o Light beaks – Insects - use small beak to get into places
o Most animals reproduce more rapidly than humas, but their populations do not
grow unchecked (there is control) Not all animals reproduce and vast numbers
die.
o Individuals of species differ from one to another in form and function.
Evolution By Natural Selection
Which individuals die in each generation is not arbitrary
