User:Tonyr8669

Evolution and Genetics for Psychology

1)The significance of Darwinism

Evolution is the central explanatory theory of biology the divergence between humans and chimpanzees is quantitative not qualitative at one point there was a shared grandparent

1.1) What problems does the theory of evolution solve?

Two major problems were solved by Darwin's theory of evolution: 1 The problem of history 2 The problem of design

1.1.1)The problem of history

similar bone patterns of vertebrates although they have different functions similar biochemical make up of cells proteins cytochrome c: made up of amino acids 104 different amino acids and same amino acids appear across species rather than not common themes with different "local" variations

Hierarchical organization in nature

if two species are similar in one detail they are more likely to be similar in another detail different species are groups together based on their shared attributes as the hierarchy goes deeper the more divergent the species become from each other Why? This is the problem of history

Solving the problem of history

Solutions: 1) different animals have always been different people always people monkeys always monkeys this cannot explain hierarchical organization Darwin : Gradual modification Phylogeny = family tree

Why does modification occur - natural selection

1.1.2)The problem of design

Creatures seem well designed for the tasks they have to perform The body has many systems that perform special tasks An engineering supermodel

Design in nature:bat echolocation

echolocation appears only when it is needed - in the dark or in murky waters energy inefficient

design oddities in nature

appearance of useless structures

solving the problem of design

a) why are there so many good design structures in nature too complex for chance pre-Darwin - a design agent problem - unparsimonious: no evidential explanation problem - non - explanatory: where does the complexity of the designer come from

b) why are some structural designs useless if the designer were that complex and brilliant why create a useless organ such as the whale pelvis

Darwin's solution to the problem of design

The cumulative effects of natural selection during evolution

Natural Selection The non random survival of useful innovations that, cumulatively can lead to what seem to be well designed structures parsimonious and explanatory vestigial structures - visible

1.2)Evolution by natural selection in a nutshell

Darwin's theory of evolution by natural selection involves Four elements:

1) Variation: There are minor characteristic variances in individual organisms.

2)Heredity: The varied characteristics are passed down from the parents to the offspring.

3)Competition: Some parents leave more offspring than others, some offspring die early, individuals have a different number of offspring that represent what the parent leaves behind.

4)Natural Selection: The offspring that bear advantages due to their characteristics will survive and those that have characteristics that have no advantage will die off.

Useful characteristics are cumulative and the longer the characteristic stays useful the more species will adopt the advantageous trait. - Think about the different organs of our senses, the eye the ear the nose each of these are marvels in engineering, yet gradually came about due to their selective advantages rather than always being there.

Being a useful characteristic enabling survival solves the problem of design as these particular traits were build up slowly and steadily. These slow and steady building blocks are called adaptations.

Homologies and analogies

The problem of history is solved by natural selection as cousins of the original will populate differently with different designs and different adaptations over time(as Dawkins calls it - up the mountain of probability).

Darwins theory of evolution identifies two types of similarity in nature:

1. homologies
2. analogies

1. homologies: These are the similarities that species have that came from a common origin.

i.e human hands and bat wings

Homologies reflect historical constructs for different species

2.analogies: These are the characteristics that vastly different species share in order to cope with their environment.

i.e streamlined shapes that are shared between whales and sharks that have a large degree of variance in the amino acids contained in their proteins but both serve to move through water with ease.

The conceptual power of Darwin's theory

Darwin's theory is based on a process that does not reflect either X: due to chance, X: due to intention, or X: due to a super all powerful designer.

Instead it explains structures in nature differently.

1.3)Incorporating genetics:The modern synthesis

The theory of natural selection was based upon transmissible components passed from parent to offspring and this is why individuals varied but during the time that Darwin was writing it was thought that heredity was a mixture of characteristics that were a combination of the two parents. At the same time a monk by the name of Gregor Mendel was exploring the possibility of hereditary particles that are passed down from one generation to the next. Rather than a blending of characteristics these were individual particles, genes, that were carried by the offspring and passed down to the next generation.

After a long time it was shown that the Mendelian idea was the reason that natural selection is possible. This is what is known as The Modern Synthesis .

Natural selection being the changes in the relative frequencies of different forms of genes in the population over the generations. In other words they are independent yet intertwined.

1.4)Common objections and misunderstandings

There are many misunderstandings about what evolution amounts to in the world

1.4.1) Evolution is just a theory

The word 'theory' can mean that one has an idea about something but there is not any scientific evidence to support it.

In evolutionary terms this is not what is meant by the word 'theory'.

Theory in evolutionary terms means something a lot more technical and scientific.

"A body of principles that explain phenomena in the world and that are used to make particular predictions about them".

Another misunderstanding is that we cannot see evolution happening so it cannot be true.

Organisms with short life spans can be observed to refute this claim such as the finches of the Galapagos islands and the sizes of their beaks. Beak size is heritable and those finches with larger beaks on the islands with an environment that necessitates a larger beak size will survive longer and have a greater chance to reproduce.

1.4.2) There are gaps in the record

Fossil records show that there can be enormous gaps of time between one species and another that are said to be in some way related but this gap means that you cannot be 100% sure.

Fossil existence only proves that evolution actually happened: The evidence more comes from the homologous patterns and adaptations of species so gaps do not disprove anything. One can look at the different species of whale that have a pelvic bone and is completely useless in their underwater environment showing that a previous generation of these whales must have walked on land at one point in time.

10)Our place in Nature

10.1) Reconstructing the tree of Life

10.1.1) The species concept

====grey areas: the genus Canis

10.2)humans as primates

10.2.3) Hominins: human ancestors after the human-chimpanzee divergence

Origins of the genus Homo

====The archaics

10.2.4) Origins of Homo sapiens

History of modern humans since their origins

===10.3

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3)Propositional Logic 2=

3.4) Theorem and sequent Introduction

3.4.3) Sequents and Theorems Proved so Far

====3.4.4) Some additional sequents and Selected P====roofs

5)Quantificational Logic 2

5.7) First-order Theories of Relations

5.7.2) Some additional notation

====5.7.3) n-ary relations and their Properties