Evolutionary Thought_General Biology 2 - SA2

General Biology 2 - SA2

George-Louis Leclerc

1. 🇫🇷 French nationalist

2. Proposed various causes of evolution with evidence

3. Wrote a 44-volume natural history series

Histoire Naturelle

George-Louis Leclerc wrote this 44-volume natural history series to describe plants and animals

Carolus Linnaeus

1. 🇸🇪 Swedish botanist

2. Developed binomial nomenclature and classification

3. Father of taxonomy

Taxonomy

Carolus Linnaeus proposed this as a way to organize biotic life into a hierarchical structure in which a scientific name was assigned to each organism (Binomial Nomenclature)

Binomial Nomenclature

• Classification system in which each species is assigned a two-part scientific name

• [ Genus ] [ Species ]

Erasmus Darwin

1. 🇬🇧 British physician and naturalist

2. First to formally theorize about evolution in Zoonomia

3. Based his conclusions on development changes in animals, artificial animal breeding, and vestigial structures

Vestigial Structures

Present body parts that lack function

Georges Cuvier

1. 🇫🇷 French Zoologist

2. Established comparative anatomy and paleontology

3. Developed Catastrophism

Catastrophism

• Written by Georges Cuvier

• Organisms are destroyed by natural catastrophes repeatedly, causing evolution and the creation of new species

James Hutton & Charles Lyell

• Proposed Uniformitarianism

Uniformitarianism

• Hutton and Lyell's principle that geologic processes that occurred in the past can be explained by current geologic processes

• The same things that have happened before will play the same way in the future

Jean-Baptiste Lamarck

• Developed Lamarckism

• Proposed two principles: "The Law of Use and Disuse", "The Inheritance of Acquired Characteristics"

• Lamarck's hypothesis: The environment can produce physical changes in an organism which can be inherited by the next generation

Lamarckism

• An evolutionary theory by Jean-Baptiste Lamarck stating that species change over time by the use and disuse of structures and the inheritance of acquired traits

• Opposes Darwinism

The Law of Use and Disuse

A principle which states that parts of the body that are used extensively develop whilst those that are not used deteriorate

The Inheritance of Acquired Characteristics

A principle which states that an organism could pass its modifications to its offspring

Thomas Malthus

1. 🏴󠁧󠁢󠁥󠁮󠁧󠁿 English economist

2. Published "An Essay on the Principle of Population" which stated that the human population's size is limited by the availability of necessary resources

3. Malthus' principle was the basis for Darwin's natural selection

Charles Darwin

1. 🏴󠁧󠁢󠁥󠁮󠁧󠁿 English naturalist

2. Proposed his theory of evolution by natural selection

3. Formulated his theory after his voyage, and wrote the book, "On The Origin of Species"

Natural Selection

A natural process resulting in the evolution of organisms best adapted to the environment

The Voyage of the Beagle

Charles Darwin's famous global voyage, where he found his first evidence of evolution

Galápagos Islands

The place where Charles Darwin made his observations during his voyage

Darwin's Study of Geology and Fossils

Earth must be old

1. Darwin observed geological changes that were the result of slow processes

2. Darwin collected fossils that differed from modern species

Observations of Nature

• Genetic Variation: Genetic variation is inheritable

• Limited Resources: Essential resources (e.g. food, space) are limited in every habitat

• Overproduction of Offspring: More offspring are born than can survive. The capacity to overproduce was a characteristic shared by all species

Inferences from Observations

• Struggle For Existence: Individuals compete for limited resources that enable them to survive

• Unequal Reproductive Success: The inherited characteristics of some individuals make them more likely to survive (natural selection)

• Descent With Modification: A population’s characteristics can change by natural selection, giving rise to new species

Modern Evolutionary Synthesis

• Genes are responsible for hereditary characteristics

• Population, not individuals, that evolve

• Speciation occurs due to the accumulation of small genetic changes