1st "No evolution" theory

(Plato)

-One world (hidden) was perfect

-Our world was imperfect copy

-Immutability-species cannot change

1st "No evolution" theory

(Aristotle)

-life could be organized into a hierarchical framework

-framework was like a ladder-Scala Natura

-for up to 2,000 years

Carolus Linnaeus

(1707-1778)

-Binomial Nomenclature

-Homo sapiens, Pan troglodytes

-based on judeo-christian culture

-followed old testament account of creation

-God created all species at once they were immutable

Georges Cuvier

(1769-1832)

-was a no evolution scientists

-championed the idea that species were not immutable

 -correctly claimed reptiles not mammals once ruled the earth

-showed that organisms were made of highly coordinated parts, and thus were too complicated to evolve

• Catastophism—fossils were evidence that life regularly gets “decimated”

Jean Baptiste Lamarck

(1774-1829)

-first scientist to champion evolution

-recognized that organisms could adapt to the environment

-Got both the patterns and mechanisms of evolution wrong!

– spontaneous generation of species

– evolution was goal-directed

– evolution proceeded by the “inheritance of acquired

characteristics”

– adaptation by the “Principle of use or disuse”

Sir Charles Lyell

(1797-1875)

-maybe most famous geologist

-first to recognize the age of the earth

-worked with Hutton (theory of uniformitarianism) to establishthat physical and chemical processes worked slowly and constantly through millenia

-influenced Darwin greatly-->gave Darwin the immense time span of the earth that he needed

-political economist

-An Essay of the Priciple of Population

-recognized that human growth made them suceptable

-Darwin applied this to all organisms

-grandfather of Charles Darwin

-may have anticipated his grandson's findings-->

The Temple of Nature (1802)

• There was a single origin of life

• Evolution has no intrinsic directionality

• Two types of evolutionary change:

– anagenesis—a single lineage changes over time

– cladogenesis—a single lineage splits to form two or

 • Cladogenesis creates biodiversity

• Transitional forms, and vestigial traits

• Comparative studies (homology homology)

• Systematics (study of the relationship of 

species to each other)

• Direct observation

Vestige- a character that is small and degenerate or imperfectly developed in comparison to one or more fully developed in an earlier stage in a past generation or closely related forms

ex. wings on osrtich and enu

Anatomy-digits, wings, etc. too similar for evolution to not be true

Behavior-behavioral traits

Embryology-development

Molecular Biology

-domestication of animals and plants

-bacterial resistence to antibiotics

-insect resistence to pestisides

ex. wild mustard-->kale, brussel sprouts, etc.

Darwin:

• A change in the physical 

characteristics of a 

population across 

generations, such that the 

frequencies of different 

physical types 

(phenotypes) is altered; 

this “microevolution microevolution” can 

lead to “macroevolution macroevolution” if 

it goes on long enough

Today:

• A change in the genetics 

of a population across 

generations, such that the 

frequencies of  different 

genetic combinations 

(genotypes) is altered

a change in the frequency of alleles at one 

or more genetic loci that occurs within a 

population between one generation and 

the next.

• Genetic loci (DNA)

• Allele (DNA)

• Frequency (proportion, aka %)

• Generation (parents
offspring)

• Population (a set of interbreeding organisms of 

a single species)

• A hereditary unit consisting of a sequence 

of DNA that occupies a specific location 

(locus) on a chromosome, and which 

helps to determine some particular 

characteristic in an organism

• Genes can undergo mutation, in which the 

DNA sequence changes. These 

“variations” of a single gene are called 

alleles.

• Diploid organisms

• Humans have 23 pairs of chromosomes

• Homozygote &  heterozygote

• Gene & allele

-cluster of genes on a chromosome

-operate with other genes rather than on their own

-genotype produces a phenotype, which is what selection "sees"

-for selection to cause evolution, the population must be variable

-creates a new allele

-in the same way that some synonyms fit better than others, some alleles have a better fit

• The idea that genotypes change through 

time via selection on phenotypes implies 

that selection has some means of judging 

the “worth” of each organism relative to 

others in its population...